Datasets:

feedback-to-code

/

mozzarella

like 1

iluwatar/java-design-patterns/955_959

iluwatar/java-design-patterns

iluwatar/java-design-patterns/955

iluwatar/java-design-patterns/959

90ea4506caa653711f69fabb99ee7ac26c4ecce7

a6fdcd4a34802deb13e9301ec15089fb3f430b28

Java 11 support: Modules

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition Java 9 introduces the Java Platform Module System. How should it be utilized in this project? In this task we create a plan what kind of modules are going to be created. Would it be possible to start without modules i.e. let everything belong to the default 'unnamed' module? And then later on possibly create module per pattern. Links: https://blog.codefx.org/java/java-9-migration-guide/ https://www.baeldung.com/java-9-modularity

diff --git a/.travis.yml b/.travis.yml index 58edddeb416e..474732c166b3 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,7 +1,7 @@ language: java dist: trusty # Xenial build environment won't allow installation of Java 8 jdk: -- oraclejdk8 +- openjdk11 env: global: @@ -21,12 +21,6 @@ after_success: - mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarcloud.io -Dsonar.login=$SONAR_TOKEN - bash update-ghpages.sh -# use latest java version available instead of travis default -addons: - apt: - packages: - - oracle-java8-installer - notifications: email: - iluwatar@gmail.com diff --git a/exclude-pmd.properties b/exclude-pmd.properties index 5a4bb138834e..c49916ca964d 100644 --- a/exclude-pmd.properties +++ b/exclude-pmd.properties @@ -24,4 +24,4 @@ com.iluwatar.servicelayer.common.BaseEntity=UnusedPrivateField com.iluwatar.doublechecked.locking.App=EmptyStatementNotInLoop,EmptyWhileStmt com.iluwatar.doublechecked.locking.InventoryTest=EmptyStatementNotInLoop,EmptyWhileStmt -domainapp.dom.modules.simple.QSimpleObject=UnusedFormalParameter \ No newline at end of file +domainapp.dom.modules.simple.QSimpleObject=UnusedFormalParameter,UnusedImports \ No newline at end of file diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 69365bd4b00a..83c18267c5a9 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -78,7 +78,7 @@ <activeByDefault>true</activeByDefault> </activation> <properties> - <datanucleus-maven-plugin.version>4.0.1</datanucleus-maven-plugin.version> + <datanucleus.version>5.2.1</datanucleus.version> </properties> <build> <pluginManagement> @@ -96,7 +96,7 @@ <pluginExecutionFilter> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-maven-plugin</artifactId> - <versionRange>[${datanucleus-maven-plugin.version},)</versionRange> + <versionRange>[${datanucleus.version},)</versionRange> <goals> <goal>enhance</goal> </goals> @@ -115,12 +115,13 @@ <plugin> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-maven-plugin</artifactId> - <version>${datanucleus-maven-plugin.version}</version> + <version>${datanucleus.version}</version> <configuration> + <log4jConfiguration>log4j.properties</log4jConfiguration> + <persistenceUnitName>simple</persistenceUnitName> + <api>JDO</api> <fork>false</fork> - <log4jConfiguration>${basedir}/log4j.properties</log4jConfiguration> <verbose>true</verbose> - <props>${basedir}/datanucleus.properties</props> </configuration> <executions> <execution> @@ -137,6 +138,7 @@ <dependency> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-core</artifactId> + <version>${datanucleus.version}</version> </dependency> <dependency> <groupId>org.datanucleus</groupId> @@ -145,6 +147,7 @@ <dependency> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-api-jdo</artifactId> + <version>${datanucleus.version}</version> </dependency> </dependencies> </profile> @@ -157,7 +160,7 @@ <plugin> <groupId>org.apache.isis.tool</groupId> <artifactId>isis-maven-plugin</artifactId> - <version>1.9.0-SNAPSHOT</version> + <version>${isis.version}</version> <configuration> <isisConfigDir>../webapp/src/main/webapp/WEB-INF</isisConfigDir> </configuration> @@ -165,7 +168,7 @@ <dependency> <groupId>org.apache.isis.example.application</groupId> <artifactId>simpleapp-dom</artifactId> - <version>1.9.0-SNAPSHOT</version> + <version>${isis.version}</version> </dependency> <!-- ... workaround to avoid conflict with plexus-default (not sure why exclusions in the isis-maven-plugin aren't sufficient, though ... --> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index c4dd52dcf652..0d5940df556d 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -85,6 +85,11 @@ <scope>test</scope> </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + <dependency> <groupId>org.hsqldb</groupId> <artifactId>hsqldb</artifactId> diff --git a/pom.xml b/pom.xml index 539da396b2d8..1feafbd559ce 100644 --- a/pom.xml +++ b/pom.xml @@ -56,7 +56,7 @@ <jackson.version>2.8.5</jackson.version> <pmd.version>3.12.0</pmd.version> <jaxb-api.version>2.3.0</jaxb-api.version> - <annotation-api.version>1.3.1</annotation-api.version> + <annotation-api.version>1.3.2</annotation-api.version> </properties> <modules> <module>abstract-factory</module> @@ -329,6 +329,11 @@ <artifactId>logback-core</artifactId> <version>${logback.version}</version> </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <version>2.3.1</version> + </dependency> </dependencies> <build> @@ -370,8 +375,7 @@ <artifactId>maven-compiler-plugin</artifactId> <version>${compiler.version}</version> <configuration> - <source>1.8</source> - <target>1.8</target> + <release>11</release> </configuration> </plugin> <plugin>

test

train

iluwatar

train

iluwatar/java-design-patterns/933_960

iluwatar/java-design-patterns

iluwatar/java-design-patterns/933

iluwatar/java-design-patterns/960

94ca25462667b15d2d4f7d5120c94a0733f53bf7

84c4b034a9f282a0d8739ef7bd4cd83813a7c454

Github reports security vulnerabilities

 

diff --git a/layers/pom.xml b/layers/pom.xml index 8237c8f4f6e0..a6d3d17199f6 100644 --- a/layers/pom.xml +++ b/layers/pom.xml @@ -41,7 +41,11 @@ </dependency> <dependency> <groupId>org.hibernate</groupId> - <artifactId>hibernate-entitymanager</artifactId> + <artifactId>hibernate-core</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> </dependency> <dependency> <groupId>commons-dbcp</groupId> diff --git a/layers/src/main/java/com/iluwatar/layers/CakeBakingServiceImpl.java b/layers/src/main/java/com/iluwatar/layers/CakeBakingServiceImpl.java index e8deee73a767..556a74c7afbf 100644 --- a/layers/src/main/java/com/iluwatar/layers/CakeBakingServiceImpl.java +++ b/layers/src/main/java/com/iluwatar/layers/CakeBakingServiceImpl.java @@ -72,18 +72,23 @@ public void bakeNewCake(CakeInfo cakeInfo) throws CakeBakingException { } } CakeToppingDao toppingBean = context.getBean(CakeToppingDao.class); - CakeTopping topping = toppingBean.findOne(matchingToppings.iterator().next().getId()); + Optional<CakeTopping> topping = toppingBean.findById(matchingToppings.iterator().next().getId()); CakeDao cakeBean = context.getBean(CakeDao.class); - Cake cake = new Cake(); - cake.setTopping(topping); - cake.setLayers(foundLayers); - cakeBean.save(cake); - topping.setCake(cake); - toppingBean.save(topping); - CakeLayerDao layerBean = context.getBean(CakeLayerDao.class); - for (CakeLayer layer : foundLayers) { - layer.setCake(cake); - layerBean.save(layer); + if (topping.isPresent()) { + Cake cake = new Cake(); + cake.setTopping(topping.get()); + cake.setLayers(foundLayers); + cakeBean.save(cake); + topping.get().setCake(cake); + toppingBean.save(topping.get()); + CakeLayerDao layerBean = context.getBean(CakeLayerDao.class); + for (CakeLayer layer : foundLayers) { + layer.setCake(cake); + layerBean.save(layer); + } + } else { + throw new CakeBakingException(String.format("Topping %s is not available", + cakeInfo.cakeToppingInfo.name)); } } diff --git a/layers/src/main/resources/applicationContext.xml b/layers/src/main/resources/applicationContext.xml index eca3670b0fbf..c149094c1fa3 100644 --- a/layers/src/main/resources/applicationContext.xml +++ b/layers/src/main/resources/applicationContext.xml @@ -50,7 +50,7 @@ <property name="dataSource" ref="dataSource" /> <property name="packagesToScan" value="com.iluwatar" /> <property name="persistenceProvider"> - <bean class="org.hibernate.ejb.HibernatePersistence" /> + <bean class="org.hibernate.jpa.HibernatePersistenceProvider" /> </property> <property name="jpaProperties"> <map> diff --git a/pom.xml b/pom.xml index acaaef6181c5..e0f64a534aef 100644 --- a/pom.xml +++ b/pom.xml @@ -28,10 +28,10 @@ <inceptionYear>2014</inceptionYear> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> - <hibernate.version>5.0.1.Final</hibernate.version> - <spring.version>4.2.4.RELEASE</spring.version> - <spring-boot.version>1.3.3.RELEASE</spring-boot.version> - <spring-data.version>1.9.2.RELEASE</spring-data.version> + <hibernate.version>5.2.18.Final</hibernate.version> + <spring.version>5.0.13.RELEASE</spring.version> + <spring-boot.version>2.0.9.RELEASE</spring-boot.version> + <spring-data.version>2.0.14.RELEASE</spring-data.version> <h2.version>1.4.190</h2.version> <junit.version>4.12</junit.version> <junit-jupiter.version>5.0.2</junit-jupiter.version> @@ -40,7 +40,7 @@ <compiler.version>3.8.1</compiler.version> <jacoco.version>0.8.4</jacoco.version> <commons-dbcp.version>1.4</commons-dbcp.version> - <camel.version>2.16.1</camel.version> + <camel.version>2.24.0</camel.version> <guava.version>19.0</guava.version> <mockito.version>1.10.19</mockito.version> <apache-httpcomponents.version>4.5.2</apache-httpcomponents.version> @@ -55,6 +55,7 @@ <aws-lambda-java-events.version>2.0.1</aws-lambda-java-events.version> <jackson.version>2.8.5</jackson.version> <pmd.version>3.12.0</pmd.version> + <log4j.version>1.2.17</log4j.version> <jaxb-api.version>2.3.0</jaxb-api.version> <annotation-api.version>1.3.1</annotation-api.version> </properties> @@ -191,11 +192,6 @@ <artifactId>hibernate-core</artifactId> <version>${hibernate.version}</version> </dependency> - <dependency> - <groupId>org.hibernate</groupId> - <artifactId>hibernate-entitymanager</artifactId> - <version>${hibernate.version}</version> - </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> @@ -300,6 +296,11 @@ <artifactId>mongo-java-driver</artifactId> <version>${mongo-java-driver.version}</version> </dependency> + <dependency> + <groupId>log4j</groupId> + <artifactId>log4j</artifactId> + <version>${log4j.version}</version> + </dependency> <dependency> <groupId>javax.xml.bind</groupId> <artifactId>jaxb-api</artifactId> diff --git a/repository/pom.xml b/repository/pom.xml index 2ccdc9da7ba5..f0340f1260ef 100644 --- a/repository/pom.xml +++ b/repository/pom.xml @@ -44,7 +44,7 @@ </dependency> <dependency> <groupId>org.hibernate</groupId> - <artifactId>hibernate-entitymanager</artifactId> + <artifactId>hibernate-core</artifactId> </dependency> <dependency> <groupId>commons-dbcp</groupId> @@ -71,5 +71,9 @@ <groupId>javax.annotation</groupId> <artifactId>javax.annotation-api</artifactId> </dependency> + <dependency> + <groupId>org.springframework.boot</groupId> + <artifactId>spring-boot-starter-test</artifactId> + </dependency> </dependencies> </project> diff --git a/repository/src/main/java/com/iluwatar/repository/App.java b/repository/src/main/java/com/iluwatar/repository/App.java index d96b4351ea38..c4a885380064 100644 --- a/repository/src/main/java/com/iluwatar/repository/App.java +++ b/repository/src/main/java/com/iluwatar/repository/App.java @@ -23,6 +23,7 @@ package com.iluwatar.repository; import java.util.List; +import java.util.Optional; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @@ -84,17 +85,17 @@ public static void main(String[] args) { nasta.setSurname("Spotakova"); repository.save(nasta); - LOGGER.info("Find by id 2: {}", repository.findOne(2L)); + LOGGER.info("Find by id 2: {}", repository.findById(2L).get()); // Remove record from Person - repository.delete(2L); + repository.deleteById(2L); // count records LOGGER.info("Count Person records: {}", repository.count()); // find by name - Person p = repository.findOne(new PersonSpecifications.NameEqualSpec("John")); - LOGGER.info("Find by John is {}", p); + Optional<Person> p = repository.findOne(new PersonSpecifications.NameEqualSpec("John")); + LOGGER.info("Find by John is {}", p.get()); // find by age persons = repository.findAll(new PersonSpecifications.AgeBetweenSpec(20, 40)); diff --git a/repository/src/main/java/com/iluwatar/repository/AppConfig.java b/repository/src/main/java/com/iluwatar/repository/AppConfig.java index c5ccb7d00002..584c09037be7 100644 --- a/repository/src/main/java/com/iluwatar/repository/AppConfig.java +++ b/repository/src/main/java/com/iluwatar/repository/AppConfig.java @@ -24,6 +24,7 @@ import java.sql.SQLException; import java.util.List; +import java.util.Optional; import java.util.Properties; import javax.sql.DataSource; @@ -32,6 +33,7 @@ import org.hibernate.jpa.HibernatePersistenceProvider; import org.slf4j.Logger; import org.slf4j.LoggerFactory; +import org.springframework.boot.SpringBootConfiguration; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import org.springframework.context.annotation.Bean; import org.springframework.data.jpa.repository.config.EnableJpaRepositories; @@ -44,6 +46,7 @@ * */ @EnableJpaRepositories +@SpringBootConfiguration public class AppConfig { private static final Logger LOGGER = LoggerFactory.getLogger(AppConfig.class); @@ -60,7 +63,7 @@ public DataSource dataSource() { basicDataSource.setUrl("jdbc:h2:~/databases/person"); basicDataSource.setUsername("sa"); basicDataSource.setPassword("sa"); - return (DataSource) basicDataSource; + return basicDataSource; } /** @@ -134,17 +137,17 @@ public static void main(String[] args) { nasta.setSurname("Spotakova"); repository.save(nasta); - LOGGER.info("Find by id 2: {}", repository.findOne(2L)); + LOGGER.info("Find by id 2: {}", repository.findById(2L).get()); // Remove record from Person - repository.delete(2L); + repository.deleteById(2L); // count records LOGGER.info("Count Person records: {}", repository.count()); // find by name - Person p = repository.findOne(new PersonSpecifications.NameEqualSpec("John")); - LOGGER.info("Find by John is {}", p); + Optional<Person> p = repository.findOne(new PersonSpecifications.NameEqualSpec("John")); + LOGGER.info("Find by John is {}", p.get()); // find by age persons = repository.findAll(new PersonSpecifications.AgeBetweenSpec(20, 40)); diff --git a/repository/src/main/resources/applicationContext.xml b/repository/src/main/resources/applicationContext.xml index 26d6cb3f4dc3..b27bb4c85f73 100644 --- a/repository/src/main/resources/applicationContext.xml +++ b/repository/src/main/resources/applicationContext.xml @@ -49,7 +49,7 @@ <property name="dataSource" ref="dataSource" /> <property name="packagesToScan" value="com.iluwatar" /> <property name="persistenceProvider"> - <bean class="org.hibernate.ejb.HibernatePersistence" /> + <bean class="org.hibernate.jpa.HibernatePersistenceProvider" /> </property> <property name="jpaProperties"> <map>

diff --git a/eip-aggregator/src/test/java/com/iluwatar/eip/aggregator/routes/AggregatorRouteTest.java b/eip-aggregator/src/test/java/com/iluwatar/eip/aggregator/routes/AggregatorRouteTest.java index 2c7d207d6f53..2b831e01958b 100644 --- a/eip-aggregator/src/test/java/com/iluwatar/eip/aggregator/routes/AggregatorRouteTest.java +++ b/eip-aggregator/src/test/java/com/iluwatar/eip/aggregator/routes/AggregatorRouteTest.java @@ -28,7 +28,7 @@ import org.junit.jupiter.api.Test; import org.junit.jupiter.api.extension.ExtendWith; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; -import org.springframework.boot.test.SpringApplicationConfiguration; +import org.springframework.boot.test.context.SpringBootTest; import org.springframework.context.annotation.ComponentScan; import org.springframework.test.annotation.DirtiesContext; import org.springframework.test.context.ActiveProfiles; @@ -44,7 +44,7 @@ * </p> */ @ExtendWith(SpringExtension.class) -@SpringApplicationConfiguration(classes = AggregatorRouteTest.class) +@SpringBootTest(classes = AggregatorRouteTest.class) @ActiveProfiles("test") @EnableAutoConfiguration @ComponentScan diff --git a/eip-splitter/src/test/java/com/iluwatar/eip/splitter/routes/SplitterRouteTest.java b/eip-splitter/src/test/java/com/iluwatar/eip/splitter/routes/SplitterRouteTest.java index 9257a4410186..334b77da03c8 100644 --- a/eip-splitter/src/test/java/com/iluwatar/eip/splitter/routes/SplitterRouteTest.java +++ b/eip-splitter/src/test/java/com/iluwatar/eip/splitter/routes/SplitterRouteTest.java @@ -28,7 +28,7 @@ import org.junit.jupiter.api.Test; import org.junit.jupiter.api.extension.ExtendWith; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; -import org.springframework.boot.test.SpringApplicationConfiguration; +import org.springframework.boot.test.context.SpringBootTest; import org.springframework.context.annotation.ComponentScan; import org.springframework.test.annotation.DirtiesContext; import org.springframework.test.context.ActiveProfiles; @@ -42,7 +42,7 @@ * </p> */ @ExtendWith(SpringExtension.class) -@SpringApplicationConfiguration(classes = SplitterRouteTest.class) +@SpringBootTest(classes = SplitterRouteTest.class) @ActiveProfiles("test") @EnableAutoConfiguration @ComponentScan diff --git a/eip-wire-tap/src/test/java/com/iluwatar/eip/wiretap/routes/WireTapRouteTest.java b/eip-wire-tap/src/test/java/com/iluwatar/eip/wiretap/routes/WireTapRouteTest.java index 449f86208258..bb433f350238 100644 --- a/eip-wire-tap/src/test/java/com/iluwatar/eip/wiretap/routes/WireTapRouteTest.java +++ b/eip-wire-tap/src/test/java/com/iluwatar/eip/wiretap/routes/WireTapRouteTest.java @@ -29,7 +29,7 @@ import org.junit.jupiter.api.Test; import org.junit.jupiter.api.extension.ExtendWith; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; -import org.springframework.boot.test.SpringApplicationConfiguration; +import org.springframework.boot.test.context.SpringBootTest; import org.springframework.context.annotation.ComponentScan; import org.springframework.test.annotation.DirtiesContext; import org.springframework.test.context.ActiveProfiles; @@ -45,7 +45,7 @@ * </p> */ @ExtendWith(SpringExtension.class) -@SpringApplicationConfiguration(classes = WireTapRouteTest.class) +@SpringBootTest(classes = WireTapRouteTest.class) @ActiveProfiles("test") @EnableAutoConfiguration @ComponentScan diff --git a/repository/src/test/java/com/iluwatar/repository/AnnotationBasedRepositoryTest.java b/repository/src/test/java/com/iluwatar/repository/AnnotationBasedRepositoryTest.java index 4cfb6e022f51..8d7e1d94b797 100644 --- a/repository/src/test/java/com/iluwatar/repository/AnnotationBasedRepositoryTest.java +++ b/repository/src/test/java/com/iluwatar/repository/AnnotationBasedRepositoryTest.java @@ -28,6 +28,7 @@ import java.util.Arrays; import java.util.List; +import java.util.Optional; import javax.annotation.Resource; @@ -35,9 +36,8 @@ import org.junit.jupiter.api.BeforeEach; import org.junit.jupiter.api.Test; import org.junit.jupiter.api.extension.ExtendWith; -import org.springframework.test.context.ContextConfiguration; +import org.springframework.boot.test.context.SpringBootTest; import org.springframework.test.context.junit.jupiter.SpringExtension; -import org.springframework.test.context.support.AnnotationConfigContextLoader; import com.google.common.collect.Lists; @@ -47,7 +47,7 @@ * */ @ExtendWith(SpringExtension.class) -@ContextConfiguration(classes = { AppConfig.class }, loader = AnnotationConfigContextLoader.class) +@SpringBootTest(classes = { AppConfig.class }) public class AnnotationBasedRepositoryTest { @Resource @@ -66,7 +66,7 @@ public class AnnotationBasedRepositoryTest { @BeforeEach public void setup() { - repository.save(persons); + repository.saveAll(persons); } @Test @@ -119,8 +119,8 @@ public void testFindAllByAgeBetweenSpec() { @Test public void testFindOneByNameEqualSpec() { - Person actual = repository.findOne(new PersonSpecifications.NameEqualSpec("Terry")); - assertEquals(terry, actual); + Optional<Person> actual = repository.findOne(new PersonSpecifications.NameEqualSpec("Terry")); + assertEquals(terry, actual.get()); } @AfterEach diff --git a/repository/src/test/java/com/iluwatar/repository/AppConfigTest.java b/repository/src/test/java/com/iluwatar/repository/AppConfigTest.java index 3fb1b427b232..1839a2523e6c 100644 --- a/repository/src/test/java/com/iluwatar/repository/AppConfigTest.java +++ b/repository/src/test/java/com/iluwatar/repository/AppConfigTest.java @@ -25,9 +25,8 @@ import org.junit.jupiter.api.Test; import org.junit.jupiter.api.extension.ExtendWith; import org.springframework.beans.factory.annotation.Autowired; -import org.springframework.test.context.ContextConfiguration; +import org.springframework.boot.test.context.SpringBootTest; import org.springframework.test.context.junit.jupiter.SpringExtension; -import org.springframework.test.context.support.AnnotationConfigContextLoader; import org.springframework.transaction.annotation.Transactional; import javax.sql.DataSource; @@ -42,7 +41,7 @@ * */ @ExtendWith(SpringExtension.class) -@ContextConfiguration(classes = { AppConfig.class }, loader = AnnotationConfigContextLoader.class) +@SpringBootTest(classes = { AppConfig.class }) public class AppConfigTest { @Autowired diff --git a/repository/src/test/java/com/iluwatar/repository/RepositoryTest.java b/repository/src/test/java/com/iluwatar/repository/RepositoryTest.java index 5b4b8e80c055..dc976cbe72d3 100644 --- a/repository/src/test/java/com/iluwatar/repository/RepositoryTest.java +++ b/repository/src/test/java/com/iluwatar/repository/RepositoryTest.java @@ -28,6 +28,7 @@ import java.util.Arrays; import java.util.List; +import java.util.Optional; import javax.annotation.Resource; @@ -35,7 +36,7 @@ import org.junit.jupiter.api.BeforeEach; import org.junit.jupiter.api.Test; import org.junit.jupiter.api.extension.ExtendWith; -import org.springframework.test.context.ContextConfiguration; +import org.springframework.boot.test.context.SpringBootTest; import org.springframework.test.context.junit.jupiter.SpringExtension; import com.google.common.collect.Lists; @@ -45,7 +46,7 @@ * by {@link org.springframework.data.jpa.domain.Specification} are also test. */ @ExtendWith(SpringExtension.class) -@ContextConfiguration(locations = { "classpath:applicationContext.xml" }) +@SpringBootTest(properties = { "locations=classpath:applicationContext.xml" }) public class RepositoryTest { @Resource @@ -64,7 +65,7 @@ public class RepositoryTest { @BeforeEach public void setup() { - repository.save(persons); + repository.saveAll(persons); } @Test @@ -115,8 +116,8 @@ public void testFindAllByAgeBetweenSpec() { @Test public void testFindOneByNameEqualSpec() { - Person actual = repository.findOne(new PersonSpecifications.NameEqualSpec("Terry")); - assertEquals(terry, actual); + Optional<Person> actual = repository.findOne(new PersonSpecifications.NameEqualSpec("Terry")); + assertEquals(terry, actual.get()); } @AfterEach

test

train

iluwatar

train

iluwatar/java-design-patterns/496_967

iluwatar/java-design-patterns

iluwatar/java-design-patterns/496

iluwatar/java-design-patterns/967

94ca25462667b15d2d4f7d5120c94a0733f53bf7

f903d7e9a9379c79742ecc61a3901bdbe2a0a318

Pipeline pattern

https://msdn.microsoft.com/en-us/library/ff963548.aspx

diff --git a/pipeline/README.md b/pipeline/README.md new file mode 100644 index 000000000000..e990affd62c7 --- /dev/null +++ b/pipeline/README.md @@ -0,0 +1,37 @@ +--- +layout: pattern +title: Pipeline +folder: pipeline +permalink: /patterns/pipeline/ +categories: Behavioral +tags: + - Java + - Functional + - Difficulty-Intermediate +--- + +## Intent +Allows processing of data in a series of stages by giving in an initial input and passing the processed output to be used by the next stages. + +## Applicability +Use the Pipeline pattern when you want to + +* execute individual stages that yields a final value +* add readability to complex sequence of operations by providing a fluent builder as an interface +* improve testability of code since stages will most likely be doing a single thing, complying to the [Single Responsibility Principle (SRP)](https://java-design-patterns.com/principles/#single-responsibility-principle) + +## Typical Use Case + +* implement stages and execute them in an ordered manner + +## Real world examples + +* [java.util.Stream](https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html) +* [Maven Build Lifecycle](http://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html) +* [Functional Java](https://github.com/functionaljava/functionaljava) + +## Credits + +* [The Pipeline Pattern — for fun and profit](https://medium.com/@aaronweatherall/the-pipeline-pattern-for-fun-and-profit-9b5f43a98130) +* [The Pipeline design pattern (in Java)](https://medium.com/@deepakbapat/the-pipeline-design-pattern-in-java-831d9ce2fe21) +* [Pipelines | Microsoft Docs](https://docs.microsoft.com/en-us/previous-versions/msp-n-p/ff963548(v=pandp.10)) \ No newline at end of file diff --git a/pipeline/pom.xml b/pipeline/pom.xml new file mode 100644 index 000000000000..7ad60d5620e4 --- /dev/null +++ b/pipeline/pom.xml @@ -0,0 +1,47 @@ +<?xml version="1.0"?> +<!-- + + The MIT License + Copyright (c) 2014-2016 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.22.0-SNAPSHOT</version> + </parent> + <artifactId>pipeline</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.mockito</groupId> + <artifactId>mockito-core</artifactId> + <scope>test</scope> + </dependency> + </dependencies> +</project> diff --git a/pipeline/src/main/java/com.iluwatar.pipeline/App.java b/pipeline/src/main/java/com.iluwatar.pipeline/App.java new file mode 100644 index 000000000000..7efa2ecca003 --- /dev/null +++ b/pipeline/src/main/java/com.iluwatar.pipeline/App.java @@ -0,0 +1,66 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +/** + * The Pipeline pattern uses ordered stages to process a sequence of input values. + * Each implemented task is represented by a stage of the pipeline. You can think of + * pipelines as similar to assembly lines in a factory, where each item in the assembly + * line is constructed in stages. The partially assembled item is passed from one assembly + * stage to another. The outputs of the assembly line occur in the same order as that of the + * inputs. + * + * Classes used in this example are suffixed with "Handlers", and synonymously refers to the + * "stage". + */ +public class App { + /** + * Specify the initial input type for the first stage handler and the expected output type + * of the last stage handler as type parameters for Pipeline. Use the fluent builder by + * calling addHandler to add more stage handlers on the pipeline. + */ + public static void main(String[] args) { + /* + Suppose we wanted to pass through a String to a series of filtering stages and convert it + as a char array on the last stage. + + - Stage handler 1 (pipe): Removing the alphabets, accepts a String input and returns the + processed String output. This will be used by the next handler as its input. + + - Stage handler 2 (pipe): Removing the digits, accepts a String input and returns the + processed String output. This shall also be used by the last handler we have. + + - Stage handler 3 (pipe): Converting the String input to a char array handler. We would + be returning a different type in here since that is what's specified by the requirement. + This means that at any stages along the pipeline, the handler can return any type of data + as long as it fulfills the requirements for the next handler's input. + + Suppose we wanted to add another handler after ConvertToCharArrayHandler. That handler + then is expected to receive an input of char[] array since that is the type being returned + by the previous handler, ConvertToCharArrayHandler. + */ + new Pipeline<>(new RemoveAlphabetsHandler()) + .addHandler(new RemoveDigitsHandler()) + .addHandler(new ConvertToCharArrayHandler()); + } +} diff --git a/pipeline/src/main/java/com.iluwatar.pipeline/ConvertToCharArrayHandler.java b/pipeline/src/main/java/com.iluwatar.pipeline/ConvertToCharArrayHandler.java new file mode 100644 index 000000000000..b69241914980 --- /dev/null +++ b/pipeline/src/main/java/com.iluwatar.pipeline/ConvertToCharArrayHandler.java @@ -0,0 +1,45 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.Arrays; + +/** + * Stage handler that converts an input String to its char[] array counterpart. + */ +class ConvertToCharArrayHandler implements Handler<String, char[]> { + + private final Logger logger = LoggerFactory.getLogger(ConvertToCharArrayHandler.class); + + @Override + public char[] process(String input) { + char[] characters = input.toCharArray(); + logger.info(String.format("Current handler: %s, input is %s of type %s, output is %s, of type %s", + ConvertToCharArrayHandler.class, input, String.class, Arrays.toString(characters), Character[].class)); + + return characters; + } +} diff --git a/pipeline/src/main/java/com.iluwatar.pipeline/Handler.java b/pipeline/src/main/java/com.iluwatar.pipeline/Handler.java new file mode 100644 index 000000000000..7d2bc0db7f59 --- /dev/null +++ b/pipeline/src/main/java/com.iluwatar.pipeline/Handler.java @@ -0,0 +1,32 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +/** + * Forms a contract to all stage handlers to accept a certain type of input and return a processed output. + * @param <I> the input type of the handler + * @param <O> the processed output type of the handler + */ +interface Handler<I, O> { + O process(I input); +} \ No newline at end of file diff --git a/pipeline/src/main/java/com.iluwatar.pipeline/Pipeline.java b/pipeline/src/main/java/com.iluwatar.pipeline/Pipeline.java new file mode 100644 index 000000000000..8e231bbc4d09 --- /dev/null +++ b/pipeline/src/main/java/com.iluwatar.pipeline/Pipeline.java @@ -0,0 +1,46 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +/** + * Main Pipeline class that initially sets the current handler. Processed output + * of the initial handler is then passed as the input to the next stage handlers. + * @param <I> the type of the input for the first stage handler + * @param <O> the final stage handler's output type + */ +class Pipeline<I, O> { + + private final Handler<I, O> currentHandler; + + Pipeline(Handler<I, O> currentHandler) { + this.currentHandler = currentHandler; + } + + <K> Pipeline<I, K> addHandler(Handler<O, K> newHandler) { + return new Pipeline<>(input -> newHandler.process(currentHandler.process(input))); + } + + O execute(I input) { + return currentHandler.process(input); + } +} \ No newline at end of file diff --git a/pipeline/src/main/java/com.iluwatar.pipeline/RemoveAlphabetsHandler.java b/pipeline/src/main/java/com.iluwatar.pipeline/RemoveAlphabetsHandler.java new file mode 100644 index 000000000000..2085052742fa --- /dev/null +++ b/pipeline/src/main/java/com.iluwatar.pipeline/RemoveAlphabetsHandler.java @@ -0,0 +1,54 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Stage handler that returns a new instance of String without the alphabet characters of the input string. + */ +class RemoveAlphabetsHandler implements Handler<String, String> { + + private final Logger logger = LoggerFactory.getLogger(RemoveAlphabetsHandler.class); + + @Override + public String process(String input) { + StringBuilder inputWithoutAlphabets = new StringBuilder(); + + for (int index = 0; index < input.length(); index++) { + char currentCharacter = input.charAt(index); + if (Character.isAlphabetic(currentCharacter)) { + continue; + } + + inputWithoutAlphabets.append(currentCharacter); + } + + String inputWithoutAlphabetsStr = inputWithoutAlphabets.toString(); + logger.info(String.format("Current handler: %s, input is %s of type %s, output is %s, of type %s", + RemoveAlphabetsHandler.class, input, String.class, inputWithoutAlphabetsStr, String.class)); + + return inputWithoutAlphabetsStr; + } +} \ No newline at end of file diff --git a/pipeline/src/main/java/com.iluwatar.pipeline/RemoveDigitsHandler.java b/pipeline/src/main/java/com.iluwatar.pipeline/RemoveDigitsHandler.java new file mode 100644 index 000000000000..e0c0aa6a87b2 --- /dev/null +++ b/pipeline/src/main/java/com.iluwatar.pipeline/RemoveDigitsHandler.java @@ -0,0 +1,54 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Stage handler that returns a new instance of String without the digit characters of the input string. + */ +class RemoveDigitsHandler implements Handler<String, String> { + + private final Logger logger = LoggerFactory.getLogger(RemoveDigitsHandler.class); + + @Override + public String process(String input) { + StringBuilder inputWithoutDigits = new StringBuilder(); + + for (int index = 0; index < input.length(); index++) { + char currentCharacter = input.charAt(index); + if (Character.isDigit(currentCharacter)) { + continue; + } + + inputWithoutDigits.append(currentCharacter); + } + + String inputWithoutDigitsStr = inputWithoutDigits.toString(); + logger.info(String.format("Current handler: %s, input is %s of type %s, output is %s, of type %s", + RemoveDigitsHandler.class, input, String.class, inputWithoutDigitsStr, String.class)); + + return inputWithoutDigitsStr; + } +} \ No newline at end of file diff --git a/pom.xml b/pom.xml index f1a586eb8b34..325a2ff00025 100644 --- a/pom.xml +++ b/pom.xml @@ -94,6 +94,7 @@ <module>property</module> <module>intercepting-filter</module> <module>producer-consumer</module> + <module>pipeline</module> <module>poison-pill</module> <module>reader-writer-lock</module> <module>lazy-loading</module>

diff --git a/pipeline/src/test/java/com.iluwatar.pipeline/AppTest.java b/pipeline/src/test/java/com.iluwatar.pipeline/AppTest.java new file mode 100644 index 000000000000..79524575c13c --- /dev/null +++ b/pipeline/src/test/java/com.iluwatar.pipeline/AppTest.java @@ -0,0 +1,37 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +import org.junit.jupiter.api.Test; + +/** + * Application Test + */ +public class AppTest { + + @Test + public void test() { + String[] args = {}; + App.main(args); + } +} diff --git a/pipeline/src/test/java/com.iluwatar.pipeline/PipelineTest.java b/pipeline/src/test/java/com.iluwatar.pipeline/PipelineTest.java new file mode 100644 index 000000000000..1a2676e25d05 --- /dev/null +++ b/pipeline/src/test/java/com.iluwatar.pipeline/PipelineTest.java @@ -0,0 +1,45 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.pipeline; + +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertArrayEquals; + +/** + * Test for {@link Pipeline} + */ +public class PipelineTest { + + @Test + public void testAddHandlersToPipeline() { + Pipeline<String, char[]> filters = new Pipeline<>(new RemoveAlphabetsHandler()) + .addHandler(new RemoveDigitsHandler()) + .addHandler(new ConvertToCharArrayHandler()); + + assertArrayEquals( + new char[] {'#', '!', '(', '&', '%', '#', '!'}, + filters.execute("#H!E(L&L0O%THE3R#34E!") + ); + } +}

test

train

iluwatar

train

iluwatar/java-design-patterns/838_968

iluwatar/java-design-patterns

iluwatar/java-design-patterns/838

iluwatar/java-design-patterns/968

94ca25462667b15d2d4f7d5120c94a0733f53bf7

f5455f9887f2613ef2b8ca16eb594d6a962196d8

Buggy dependencies

Hi, there! We are a research team working on third-party library analysis. We have found that some widely-used third-party libraries in your project have major/critical bugs, which will degrade the quality of your project. We highly recommend you to update those libraries to new versions. We have attached the buggy third-party libraries and corresponding jira issue links below for you to have more detailed information. 1 org.apache.httpcomponents httpclient (pom in maven central) version: 4.5.1 Jira issues: Add convenience methods to fluent API class Request affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1696?filter=allopenissues GET request should support body affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1703?filter=allopenissues Delete obsolete clone method affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1709?filter=allopenissues NTLMEngineImpl.Type1Message not thread safe but declared as a constant affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1715?filter=allopenissues HttpClient 4.5.1 may perform multiple requests on the same connection despite having "Connection: close" header. affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1723?filter=allopenissues The deprecated SSLSocketFactory does not contain the SNI fix found in the SSLConnectionSocketFactory class affectsVersions:4.4.1;4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1726?filter=allopenissues org.apache.http.impl.client.AbstractHttpClient#createClientConnectionManager Does not account for context class loader affectsVersions:4.4.1;4.5;4.5.1;4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1727?filter=allopenissues Malformed path not handled well affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1803?filter=allopenissues NTLM authentication error: Unexpected state: MSG_TYPE3_GENERATED affectsVersions:4.5.1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1882?filter=allopenissues 2 org.apache.httpcomponents httpclient (pom.xml) version: 4.5.2 Jira issues: org.apache.http.impl.client.AbstractHttpClient#createClientConnectionManager Does not account for context class loader affectsVersions:4.4.1;4.5;4.5.1;4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1727?filter=allopenissues Memory Leak in OSGi support affectsVersions:4.4.1;4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1749?filter=allopenissues SystemDefaultRoutePlanner: Possible null pointer dereference affectsVersions:4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1766?filter=allopenissues Null pointer dereference in EofSensorInputStream and ResponseEntityProxy affectsVersions:4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1767?filter=allopenissues [OSGi] WeakList needs to support "clear" method affectsVersions:4.5.2;5.0 Alpha1 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1772?filter=allopenissues [OSGi] HttpProxyConfigurationActivator does not unregister HttpClientBuilderFactory affectsVersions:4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1773?filter=allopenissues Why is Retry around Redirect and not the other way round affectsVersions:4.5.2 https://issues.apache.org/jira/projects/HTTPCLIENT/issues/HTTPCLIENT-1800?filter=allopenissues 3 org.slf4j slf4j-api (pom.xml) version: 1.7.21 Jira issues: Cannot re-initialize the SimpleLogger anymore. affectsVersions:1.7.21 https://jira.qos.ch/projects/SLF4J/issues/SLF4J-370?filter=allopenissues Marker lost in EventRecodingLogger affectsVersions:1.7.21 https://jira.qos.ch/projects/SLF4J/issues/SLF4J-379?filter=allopenissues Support for JCL 1.2 affectsVersions:1.7.21 https://jira.qos.ch/projects/SLF4J/issues/SLF4J-383?filter=allopenissues 4 ch.qos.logback logback-classic (pom.xml) version: 1.1.7 Jira issues: SMTPAppender configuration error since Logback 1.1.7 affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1158?filter=allopenissues Don't swallow Errors affectsVersions:1.1.6;1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1159?filter=allopenissues Incorrect "contains multiple setters for the same property" error output for bridge methods affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1164?filter=allopenissues MDCFilter crashes with NPE when value is not set affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1165?filter=allopenissues totalSizeCap not work as expected affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1166?filter=allopenissues Log file handle/descriptor not closed/released after WAR file redeploy affectsVersions:1.1.6;1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1170?filter=allopenissues FilenamePattern used to TimeBasedArchiveRemover is limited for 999 files affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1175?filter=allopenissues SizeAndTimeBasedFNATP should not start in the absence of maxFileSize property affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1176?filter=allopenissues RollingFileAppender throws UnsupportedOperationEx after elapsed period affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1181?filter=allopenissues scanPeriod attribute is required by logback-classic for auto-reload to work affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1194?filter=allopenissues RollingFileAppender generating a large numbers of .tmp files affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1238?filter=allopenissues Allow leading zeros in %i pattern affectsVersions:1.1.7 https://jira.qos.ch/projects/LOGBACK/issues/LOGBACK-1248?filter=allopenissues Sincerely~ FDU Software Engineering Lab Jan 7th,2019

diff --git a/pom.xml b/pom.xml index acaaef6181c5..539da396b2d8 100644 --- a/pom.xml +++ b/pom.xml @@ -43,12 +43,12 @@ <camel.version>2.16.1</camel.version> <guava.version>19.0</guava.version> <mockito.version>1.10.19</mockito.version> - <apache-httpcomponents.version>4.5.2</apache-httpcomponents.version> + <apache-httpcomponents.version>4.5.10</apache-httpcomponents.version> <htmlunit.version>2.22</htmlunit.version> <guice.version>4.0</guice.version> <mongo-java-driver.version>3.3.0</mongo-java-driver.version> - <slf4j.version>1.7.21</slf4j.version> - <logback.version>1.1.7</logback.version> + <slf4j.version>1.7.28</slf4j.version> + <logback.version>1.2.3</logback.version> <aws-lambda-core.version>1.1.0</aws-lambda-core.version> <aws-java-sdk-dynamodb.version>1.11.289</aws-java-sdk-dynamodb.version> <aws-lambda-log4j.version>1.0.0</aws-lambda-log4j.version>

test

train

iluwatar

train

iluwatar/java-design-patterns/549_971

iluwatar/java-design-patterns

iluwatar/java-design-patterns/549

iluwatar/java-design-patterns/971

55b0341c8dc28ab84412d535bee9ecbb461fa081

1d4a7681e2d8699457c557fbab3d69d5f8aa105b

"Aggregator microservices" design pattern doesn't show exception handling

"Aggregator microservices" design pattern doesn't show how exception handling would be done if the one or multiple services used are down and how client calling the aggregator microservice would cope in this situation.

diff --git a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java index e96ac9d43c2c..dbed50fc6610 100644 --- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java +++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java @@ -51,9 +51,23 @@ public class Aggregator { */ @RequestMapping(path = "/product", method = RequestMethod.GET) public Product getProduct() { + var product = new Product(); - product.setTitle(informationClient.getProductTitle()); - product.setProductInventories(inventoryClient.getProductInventories()); + String productTitle = informationClient.getProductTitle(); + Integer productInventory = inventoryClient.getProductInventories(); + + if (productTitle != null) { + product.setTitle(productTitle); + } else { + product.setTitle("Error: Fetching Product Title Failed"); //Fallback to error message + } + + if (productInventory != null) { + product.setProductInventories(productInventory); + } else { + product.setProductInventories(-1); //Fallback to default error inventory + } + return product; } diff --git a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java index ed325be0070f..22369350a203 100644 --- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java +++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java @@ -28,5 +28,5 @@ */ public interface ProductInventoryClient { - int getProductInventories(); + Integer getProductInventories(); } diff --git a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java index c43fe84c61ca..fcd824de7aca 100644 --- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java +++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java @@ -42,8 +42,8 @@ public class ProductInventoryClientImpl implements ProductInventoryClient { private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class); @Override - public int getProductInventories() { - var response = "0"; + public Integer getProductInventories() { + var response = ""; var request = HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:51516/inventories")).build(); var client = HttpClient.newHttpClient(); @@ -55,6 +55,10 @@ public int getProductInventories() { } catch (InterruptedException ie) { LOGGER.error("InterruptedException Occurred", ie); } - return Integer.parseInt(response); + if("".equalsIgnoreCase(response)) { + return null; + } else { + return Integer.parseInt(response); + } } }

train

train

neerajmahajan

train

iluwatar/java-design-patterns/973_975

iluwatar/java-design-patterns

iluwatar/java-design-patterns/973

iluwatar/java-design-patterns/975

71f26c3e59f45d0e62b7137a75705a522d43cdec

e36bbbb22bad5e24c15ea2d185309033580f2ba8

Java 11 support: Update Travis to build on JDK 11

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition The purpose is to update the Travis CI build to use JDK 11, instead of the old JDK 8.

diff --git a/cqrs/pom.xml b/cqrs/pom.xml index beb195473ced..fc89a93b7c79 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -39,4 +39,25 @@ <artifactId>hibernate-core</artifactId> </dependency> </dependencies> + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <scope>test</scope> + <version>2.1.17</version> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index f56ae78deb73..39270f02097e 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -70,4 +70,24 @@ </dependency> </dependencies> + + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> + </project> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 2bc3eec8402b..7319f651939c 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -70,4 +70,25 @@ </dependency> </dependencies> + + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> + + </project> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index efca8d3c4cfb..a9d30924204a 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -70,4 +70,23 @@ </dependency> </dependencies> + + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/naked-objects/dom/exclude-pmd.properties b/naked-objects/dom/exclude-pmd.properties new file mode 100644 index 000000000000..bda3929accc6 --- /dev/null +++ b/naked-objects/dom/exclude-pmd.properties @@ -0,0 +1,24 @@ +# +# The MIT License +# Copyright (c) 2014-2016 Ilkka Seppälä +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# + +domainapp.dom.modules.simple.QSimpleObject=UnusedFormalParameter \ No newline at end of file diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 69365bd4b00a..039afc373727 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -78,7 +78,7 @@ <activeByDefault>true</activeByDefault> </activation> <properties> - <datanucleus-maven-plugin.version>4.0.1</datanucleus-maven-plugin.version> + <datanucleus-maven-plugin.version>5.2.1</datanucleus-maven-plugin.version> </properties> <build> <pluginManagement> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index c4dd52dcf652..f12f4ae1e368 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -122,6 +122,20 @@ </repository> </repositories> --> + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/pom.xml b/pom.xml index d812d27c4c54..efeee185c788 100644 --- a/pom.xml +++ b/pom.xml @@ -56,7 +56,8 @@ <jackson.version>2.8.5</jackson.version> <pmd.version>3.12.0</pmd.version> <log4j.version>1.2.17</log4j.version> - <jaxb-api.version>2.3.0</jaxb-api.version> + <jaxb-api.version>2.3.1</jaxb-api.version> + <jaxb-impl.version>2.3.2</jaxb-impl.version> <annotation-api.version>1.3.1</annotation-api.version> </properties> <modules> @@ -314,6 +315,11 @@ <artifactId>javax.annotation-api</artifactId> <version>${annotation-api.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <version>${jaxb-impl.version}</version> + </dependency> </dependencies> </dependencyManagement> @@ -494,4 +500,27 @@ </plugins> </reporting> + <profiles> + <profile> + <id>jdk11-dep-management</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencyManagement> + <dependencies> + <dependency> + <groupId>org.javassist</groupId> + <artifactId>javassist</artifactId> + <version>3.25.0-GA</version> + </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + <version>1.3.2</version> + </dependency> + </dependencies> + </dependencyManagement> + </profile> + </profiles> + </project> diff --git a/service-layer/pom.xml b/service-layer/pom.xml index 403a896a4613..4edd950740a8 100644 --- a/service-layer/pom.xml +++ b/service-layer/pom.xml @@ -52,4 +52,22 @@ <scope>test</scope> </dependency> </dependencies> + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/trampoline/pom.xml b/trampoline/pom.xml index 1e019ef31297..86726a1186bc 100644 --- a/trampoline/pom.xml +++ b/trampoline/pom.xml @@ -51,7 +51,7 @@ <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> - <version>1.16.18</version> + <version>1.18.10</version> </dependency>

train

train

iluwatar

train

iluwatar/java-design-patterns/948_975

iluwatar/java-design-patterns

iluwatar/java-design-patterns/948

iluwatar/java-design-patterns/975

71f26c3e59f45d0e62b7137a75705a522d43cdec

e36bbbb22bad5e24c15ea2d185309033580f2ba8

Java 11 support: Run the build on JDK 11

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition In this task we run the regular build entirely on the newer JDK 11 in a way that lets us gather all errors instead of stopping the build to the first failure (see https://blog.codefx.org/java/planning-your-java-9-update/). Report the list of errors under this issue.

diff --git a/cqrs/pom.xml b/cqrs/pom.xml index beb195473ced..fc89a93b7c79 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -39,4 +39,25 @@ <artifactId>hibernate-core</artifactId> </dependency> </dependencies> + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <scope>test</scope> + <version>2.1.17</version> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index f56ae78deb73..39270f02097e 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -70,4 +70,24 @@ </dependency> </dependencies> + + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> + </project> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 2bc3eec8402b..7319f651939c 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -70,4 +70,25 @@ </dependency> </dependencies> + + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> + + </project> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index efca8d3c4cfb..a9d30924204a 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -70,4 +70,23 @@ </dependency> </dependencies> + + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/naked-objects/dom/exclude-pmd.properties b/naked-objects/dom/exclude-pmd.properties new file mode 100644 index 000000000000..bda3929accc6 --- /dev/null +++ b/naked-objects/dom/exclude-pmd.properties @@ -0,0 +1,24 @@ +# +# The MIT License +# Copyright (c) 2014-2016 Ilkka Seppälä +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# + +domainapp.dom.modules.simple.QSimpleObject=UnusedFormalParameter \ No newline at end of file diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 69365bd4b00a..039afc373727 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -78,7 +78,7 @@ <activeByDefault>true</activeByDefault> </activation> <properties> - <datanucleus-maven-plugin.version>4.0.1</datanucleus-maven-plugin.version> + <datanucleus-maven-plugin.version>5.2.1</datanucleus-maven-plugin.version> </properties> <build> <pluginManagement> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index c4dd52dcf652..f12f4ae1e368 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -122,6 +122,20 @@ </repository> </repositories> --> + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/pom.xml b/pom.xml index d812d27c4c54..efeee185c788 100644 --- a/pom.xml +++ b/pom.xml @@ -56,7 +56,8 @@ <jackson.version>2.8.5</jackson.version> <pmd.version>3.12.0</pmd.version> <log4j.version>1.2.17</log4j.version> - <jaxb-api.version>2.3.0</jaxb-api.version> + <jaxb-api.version>2.3.1</jaxb-api.version> + <jaxb-impl.version>2.3.2</jaxb-impl.version> <annotation-api.version>1.3.1</annotation-api.version> </properties> <modules> @@ -314,6 +315,11 @@ <artifactId>javax.annotation-api</artifactId> <version>${annotation-api.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <version>${jaxb-impl.version}</version> + </dependency> </dependencies> </dependencyManagement> @@ -494,4 +500,27 @@ </plugins> </reporting> + <profiles> + <profile> + <id>jdk11-dep-management</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencyManagement> + <dependencies> + <dependency> + <groupId>org.javassist</groupId> + <artifactId>javassist</artifactId> + <version>3.25.0-GA</version> + </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + <version>1.3.2</version> + </dependency> + </dependencies> + </dependencyManagement> + </profile> + </profiles> + </project> diff --git a/service-layer/pom.xml b/service-layer/pom.xml index 403a896a4613..4edd950740a8 100644 --- a/service-layer/pom.xml +++ b/service-layer/pom.xml @@ -52,4 +52,22 @@ <scope>test</scope> </dependency> </dependencies> + <profiles> + <profile> + <id>jdk11-deps</id> + <activation> + <jdk>[11,)</jdk> + </activation> + <dependencies> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + </dependencies> + </profile> + </profiles> </project> diff --git a/trampoline/pom.xml b/trampoline/pom.xml index 1e019ef31297..86726a1186bc 100644 --- a/trampoline/pom.xml +++ b/trampoline/pom.xml @@ -51,7 +51,7 @@ <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> - <version>1.16.18</version> + <version>1.18.10</version> </dependency>

train

train

iluwatar

train

iluwatar/java-design-patterns/977_979

iluwatar/java-design-patterns

iluwatar/java-design-patterns/977

iluwatar/java-design-patterns/979

e36bbbb22bad5e24c15ea2d185309033580f2ba8

fcc1c0a27cbf92f07d4a2d9164598c883da74416

Remove maven-pmd-plugin from project

We are using SonarCloud for static source code analysis so maven-pmd-plugin is included really for no particular reason. Let's remove it from the project.

diff --git a/exclude-pmd.properties b/exclude-pmd.properties deleted file mode 100644 index 5a4bb138834e..000000000000 --- a/exclude-pmd.properties +++ /dev/null @@ -1,27 +0,0 @@ -# -# The MIT License -# Copyright (c) 2014-2016 Ilkka Seppälä -# -# Permission is hereby granted, free of charge, to any person obtaining a copy -# of this software and associated documentation files (the "Software"), to deal -# in the Software without restriction, including without limitation the rights -# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -# copies of the Software, and to permit persons to whom the Software is -# furnished to do so, subject to the following conditions: -# -# The above copyright notice and this permission notice shall be included in -# all copies or substantial portions of the Software. -# -# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN -# THE SOFTWARE. -# - -com.iluwatar.servicelayer.common.BaseEntity=UnusedPrivateField -com.iluwatar.doublechecked.locking.App=EmptyStatementNotInLoop,EmptyWhileStmt -com.iluwatar.doublechecked.locking.InventoryTest=EmptyStatementNotInLoop,EmptyWhileStmt -domainapp.dom.modules.simple.QSimpleObject=UnusedFormalParameter \ No newline at end of file diff --git a/pom.xml b/pom.xml index d812d27c4c54..bb3e31d300fb 100644 --- a/pom.xml +++ b/pom.xml @@ -54,7 +54,6 @@ <aws-lambda-log4j.version>1.0.0</aws-lambda-log4j.version> <aws-lambda-java-events.version>2.0.1</aws-lambda-java-events.version> <jackson.version>2.8.5</jackson.version> - <pmd.version>3.12.0</pmd.version> <log4j.version>1.2.17</log4j.version> <jaxb-api.version>2.3.0</jaxb-api.version> <annotation-api.version>1.3.1</annotation-api.version> @@ -434,26 +433,6 @@ </execution> </executions> </plugin> - <plugin> - <groupId>org.apache.maven.plugins</groupId> - <artifactId>maven-pmd-plugin</artifactId> - <version>${pmd.version}</version> - <configuration> - <failOnViolation>true</failOnViolation> - <failurePriority>5</failurePriority> - <printFailingErrors>true</printFailingErrors> - </configuration> - <executions> - <execution> - <goals> - <goal>check</goal> - </goals> - <configuration> - <excludeFromFailureFile>exclude-pmd.properties</excludeFromFailureFile> - </configuration> - </execution> - </executions> - </plugin> <plugin> <groupId>com.mycila</groupId> @@ -481,11 +460,6 @@ <reporting> <plugins> - <plugin> - <groupId>org.apache.maven.plugins</groupId> - <artifactId>maven-pmd-plugin</artifactId> - <version>${pmd.version}</version> - </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jxr-plugin</artifactId>

val

train

iluwatar

train

iluwatar/java-design-patterns/964_980

iluwatar/java-design-patterns

iluwatar/java-design-patterns/964

iluwatar/java-design-patterns/980

e36bbbb22bad5e24c15ea2d185309033580f2ba8

6faec9901a2380800aa50af538c8669539997176

Java 11 support: Upgrade dependencies

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition Upgrade project dependencies so that they support Java 11. Most of the dependencies can be found in main `pom.xml` dependencyManagement section. Links: https://www.infoq.com/articles/upgrading-java-8-to-12/ and https://winterbe.com/posts/2018/08/29/migrate-maven-projects-to-java-11-jigsaw/

diff --git a/.travis.yml b/.travis.yml index 84b031fadcc1..45323dcfd457 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,7 +1,6 @@ language: java dist: xenial jdk: -- openjdk8 - openjdk11 env: diff --git a/cqrs/pom.xml b/cqrs/pom.xml index fc89a93b7c79..9c9458505aba 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -38,26 +38,18 @@ <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <scope>test</scope> + <version>2.1.17</version> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <scope>test</scope> + </dependency> + </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - <scope>test</scope> - <version>2.1.17</version> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - <scope>test</scope> - </dependency> - </dependencies> - </profile> - </profiles> + </project> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index 39270f02097e..6a5e32845cfc 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -47,6 +47,15 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,23 +80,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 7319f651939c..9769d08034a7 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,24 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - - </project> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index a9d30924204a..c96063418c46 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,22 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> </project> diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 039afc373727..e816c76bbd78 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -36,6 +36,17 @@ </excludes> </resource> </resources> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-compiler-plugin</artifactId> + <version>${compiler.version}</version> + <configuration> + <source>8</source> + <target>8</target> + </configuration> + </plugin> + </plugins> </build> <dependencies> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index f12f4ae1e368..7365a71a9acb 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -90,6 +90,11 @@ <artifactId>hsqldb</artifactId> </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + <!-- uncomment to enable enhanced cucumber-jvm reporting http://www.masterthought.net/section/cucumber-reporting @@ -122,20 +127,5 @@ </repository> </repositories> --> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/pom.xml b/pom.xml index efeee185c788..b3756e1c06fb 100644 --- a/pom.xml +++ b/pom.xml @@ -58,7 +58,7 @@ <log4j.version>1.2.17</log4j.version> <jaxb-api.version>2.3.1</jaxb-api.version> <jaxb-impl.version>2.3.2</jaxb-impl.version> - <annotation-api.version>1.3.1</annotation-api.version> + <annotation-api.version>1.3.2</annotation-api.version> </properties> <modules> <module>abstract-factory</module> @@ -320,6 +320,11 @@ <artifactId>jaxb-impl</artifactId> <version>${jaxb-impl.version}</version> </dependency> + <dependency> + <groupId>org.javassist</groupId> + <artifactId>javassist</artifactId> + <version>3.25.0-GA</version> + </dependency> </dependencies> </dependencyManagement> @@ -380,8 +385,8 @@ <artifactId>maven-compiler-plugin</artifactId> <version>${compiler.version}</version> <configuration> - <source>1.8</source> - <target>1.8</target> + <source>11</source> + <target>11</target> </configuration> </plugin> <plugin> @@ -500,27 +505,4 @@ </plugins> </reporting> - <profiles> - <profile> - <id>jdk11-dep-management</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencyManagement> - <dependencies> - <dependency> - <groupId>org.javassist</groupId> - <artifactId>javassist</artifactId> - <version>3.25.0-GA</version> - </dependency> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - <version>1.3.2</version> - </dependency> - </dependencies> - </dependencyManagement> - </profile> - </profiles> - </project> diff --git a/service-layer/pom.xml b/service-layer/pom.xml index 4edd950740a8..057a701341a7 100644 --- a/service-layer/pom.xml +++ b/service-layer/pom.xml @@ -41,6 +41,14 @@ <groupId>com.h2database</groupId> <artifactId>h2</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> @@ -52,22 +60,5 @@ <scope>test</scope> </dependency> </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> + </project>

val

train

iluwatar

train

iluwatar/java-design-patterns/976_980

iluwatar/java-design-patterns

iluwatar/java-design-patterns/976

iluwatar/java-design-patterns/980

e36bbbb22bad5e24c15ea2d185309033580f2ba8

6faec9901a2380800aa50af538c8669539997176

Java 11 support: Build with JDK11

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition Configure Maven plugins to use Java 11 and verify that build works using JDK11 (see https://winterbe.com/posts/2018/08/29/migrate-maven-projects-to-java-11-jigsaw/ and https://www.baeldung.com/maven-java-version)

diff --git a/.travis.yml b/.travis.yml index 84b031fadcc1..45323dcfd457 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,7 +1,6 @@ language: java dist: xenial jdk: -- openjdk8 - openjdk11 env: diff --git a/cqrs/pom.xml b/cqrs/pom.xml index fc89a93b7c79..9c9458505aba 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -38,26 +38,18 @@ <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <scope>test</scope> + <version>2.1.17</version> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <scope>test</scope> + </dependency> + </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - <scope>test</scope> - <version>2.1.17</version> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - <scope>test</scope> - </dependency> - </dependencies> - </profile> - </profiles> + </project> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index 39270f02097e..6a5e32845cfc 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -47,6 +47,15 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,23 +80,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 7319f651939c..9769d08034a7 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,24 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - - </project> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index a9d30924204a..c96063418c46 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,22 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> </project> diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 039afc373727..e816c76bbd78 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -36,6 +36,17 @@ </excludes> </resource> </resources> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-compiler-plugin</artifactId> + <version>${compiler.version}</version> + <configuration> + <source>8</source> + <target>8</target> + </configuration> + </plugin> + </plugins> </build> <dependencies> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index f12f4ae1e368..7365a71a9acb 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -90,6 +90,11 @@ <artifactId>hsqldb</artifactId> </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + <!-- uncomment to enable enhanced cucumber-jvm reporting http://www.masterthought.net/section/cucumber-reporting @@ -122,20 +127,5 @@ </repository> </repositories> --> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/pom.xml b/pom.xml index efeee185c788..b3756e1c06fb 100644 --- a/pom.xml +++ b/pom.xml @@ -58,7 +58,7 @@ <log4j.version>1.2.17</log4j.version> <jaxb-api.version>2.3.1</jaxb-api.version> <jaxb-impl.version>2.3.2</jaxb-impl.version> - <annotation-api.version>1.3.1</annotation-api.version> + <annotation-api.version>1.3.2</annotation-api.version> </properties> <modules> <module>abstract-factory</module> @@ -320,6 +320,11 @@ <artifactId>jaxb-impl</artifactId> <version>${jaxb-impl.version}</version> </dependency> + <dependency> + <groupId>org.javassist</groupId> + <artifactId>javassist</artifactId> + <version>3.25.0-GA</version> + </dependency> </dependencies> </dependencyManagement> @@ -380,8 +385,8 @@ <artifactId>maven-compiler-plugin</artifactId> <version>${compiler.version}</version> <configuration> - <source>1.8</source> - <target>1.8</target> + <source>11</source> + <target>11</target> </configuration> </plugin> <plugin> @@ -500,27 +505,4 @@ </plugins> </reporting> - <profiles> - <profile> - <id>jdk11-dep-management</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencyManagement> - <dependencies> - <dependency> - <groupId>org.javassist</groupId> - <artifactId>javassist</artifactId> - <version>3.25.0-GA</version> - </dependency> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - <version>1.3.2</version> - </dependency> - </dependencies> - </dependencyManagement> - </profile> - </profiles> - </project> diff --git a/service-layer/pom.xml b/service-layer/pom.xml index 4edd950740a8..057a701341a7 100644 --- a/service-layer/pom.xml +++ b/service-layer/pom.xml @@ -41,6 +41,14 @@ <groupId>com.h2database</groupId> <artifactId>h2</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> @@ -52,22 +60,5 @@ <scope>test</scope> </dependency> </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> + </project>

train

train

iluwatar

train

iluwatar/java-design-patterns/950_980

iluwatar/java-design-patterns

iluwatar/java-design-patterns/950

iluwatar/java-design-patterns/980

e36bbbb22bad5e24c15ea2d185309033580f2ba8

6faec9901a2380800aa50af538c8669539997176

Java 11 support: JDeps

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition There’s a tool, JDeps, that’s part of the JDK 11 that you can run with a flag of -jdkinternals to check to see if a set of classes is using something it shouldn’t. Run JDeps on the project and its dependencies (see https://blog.codefx.org/tools/jdeps-tutorial-analyze-java-project-dependencies/) and report findings under this issue.

diff --git a/.travis.yml b/.travis.yml index 84b031fadcc1..45323dcfd457 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,7 +1,6 @@ language: java dist: xenial jdk: -- openjdk8 - openjdk11 env: diff --git a/cqrs/pom.xml b/cqrs/pom.xml index fc89a93b7c79..9c9458505aba 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -38,26 +38,18 @@ <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <scope>test</scope> + <version>2.1.17</version> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <scope>test</scope> + </dependency> + </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - <scope>test</scope> - <version>2.1.17</version> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - <scope>test</scope> - </dependency> - </dependencies> - </profile> - </profiles> + </project> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index 39270f02097e..6a5e32845cfc 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -47,6 +47,15 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,23 +80,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 7319f651939c..9769d08034a7 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,24 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - - </project> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index a9d30924204a..c96063418c46 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,22 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> </project> diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 039afc373727..e816c76bbd78 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -36,6 +36,17 @@ </excludes> </resource> </resources> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-compiler-plugin</artifactId> + <version>${compiler.version}</version> + <configuration> + <source>8</source> + <target>8</target> + </configuration> + </plugin> + </plugins> </build> <dependencies> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index f12f4ae1e368..7365a71a9acb 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -90,6 +90,11 @@ <artifactId>hsqldb</artifactId> </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + <!-- uncomment to enable enhanced cucumber-jvm reporting http://www.masterthought.net/section/cucumber-reporting @@ -122,20 +127,5 @@ </repository> </repositories> --> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/pom.xml b/pom.xml index efeee185c788..b3756e1c06fb 100644 --- a/pom.xml +++ b/pom.xml @@ -58,7 +58,7 @@ <log4j.version>1.2.17</log4j.version> <jaxb-api.version>2.3.1</jaxb-api.version> <jaxb-impl.version>2.3.2</jaxb-impl.version> - <annotation-api.version>1.3.1</annotation-api.version> + <annotation-api.version>1.3.2</annotation-api.version> </properties> <modules> <module>abstract-factory</module> @@ -320,6 +320,11 @@ <artifactId>jaxb-impl</artifactId> <version>${jaxb-impl.version}</version> </dependency> + <dependency> + <groupId>org.javassist</groupId> + <artifactId>javassist</artifactId> + <version>3.25.0-GA</version> + </dependency> </dependencies> </dependencyManagement> @@ -380,8 +385,8 @@ <artifactId>maven-compiler-plugin</artifactId> <version>${compiler.version}</version> <configuration> - <source>1.8</source> - <target>1.8</target> + <source>11</source> + <target>11</target> </configuration> </plugin> <plugin> @@ -500,27 +505,4 @@ </plugins> </reporting> - <profiles> - <profile> - <id>jdk11-dep-management</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencyManagement> - <dependencies> - <dependency> - <groupId>org.javassist</groupId> - <artifactId>javassist</artifactId> - <version>3.25.0-GA</version> - </dependency> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - <version>1.3.2</version> - </dependency> - </dependencies> - </dependencyManagement> - </profile> - </profiles> - </project> diff --git a/service-layer/pom.xml b/service-layer/pom.xml index 4edd950740a8..057a701341a7 100644 --- a/service-layer/pom.xml +++ b/service-layer/pom.xml @@ -41,6 +41,14 @@ <groupId>com.h2database</groupId> <artifactId>h2</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> @@ -52,22 +60,5 @@ <scope>test</scope> </dependency> </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> + </project>

test

train

iluwatar

train

iluwatar/java-design-patterns/949_980

iluwatar/java-design-patterns

iluwatar/java-design-patterns/949

iluwatar/java-design-patterns/980

e36bbbb22bad5e24c15ea2d185309033580f2ba8

6faec9901a2380800aa50af538c8669539997176

Java 11 support: Run the project against Java 11 runtime

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition Build the project using the old JDK 8, but try to run some of the pattern examples we have against a newer Java 11 runtime (see https://blog.codefx.org/java/planning-your-java-9-update/). Record the errors under this issue.

diff --git a/.travis.yml b/.travis.yml index 84b031fadcc1..45323dcfd457 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,7 +1,6 @@ language: java dist: xenial jdk: -- openjdk8 - openjdk11 env: diff --git a/cqrs/pom.xml b/cqrs/pom.xml index fc89a93b7c79..9c9458505aba 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -38,26 +38,18 @@ <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + <scope>test</scope> + <version>2.1.17</version> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + <scope>test</scope> + </dependency> + </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - <scope>test</scope> - <version>2.1.17</version> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - <scope>test</scope> - </dependency> - </dependencies> - </profile> - </profiles> + </project> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index 39270f02097e..6a5e32845cfc 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -47,6 +47,15 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,23 +80,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 7319f651939c..9769d08034a7 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,24 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - - </project> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index a9d30924204a..c96063418c46 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -47,6 +47,16 @@ <version>${camel.version}</version> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> + + <!-- Testing --> <dependency> <groupId>com.github.sbrannen</groupId> @@ -71,22 +81,4 @@ </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> </project> diff --git a/naked-objects/dom/pom.xml b/naked-objects/dom/pom.xml index 039afc373727..e816c76bbd78 100644 --- a/naked-objects/dom/pom.xml +++ b/naked-objects/dom/pom.xml @@ -36,6 +36,17 @@ </excludes> </resource> </resources> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-compiler-plugin</artifactId> + <version>${compiler.version}</version> + <configuration> + <source>8</source> + <target>8</target> + </configuration> + </plugin> + </plugins> </build> <dependencies> diff --git a/naked-objects/integtests/pom.xml b/naked-objects/integtests/pom.xml index f12f4ae1e368..7365a71a9acb 100644 --- a/naked-objects/integtests/pom.xml +++ b/naked-objects/integtests/pom.xml @@ -90,6 +90,11 @@ <artifactId>hsqldb</artifactId> </dependency> + <dependency> + <groupId>javax.annotation</groupId> + <artifactId>javax.annotation-api</artifactId> + </dependency> + <!-- uncomment to enable enhanced cucumber-jvm reporting http://www.masterthought.net/section/cucumber-reporting @@ -122,20 +127,5 @@ </repository> </repositories> --> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> - </project> diff --git a/pom.xml b/pom.xml index efeee185c788..b3756e1c06fb 100644 --- a/pom.xml +++ b/pom.xml @@ -58,7 +58,7 @@ <log4j.version>1.2.17</log4j.version> <jaxb-api.version>2.3.1</jaxb-api.version> <jaxb-impl.version>2.3.2</jaxb-impl.version> - <annotation-api.version>1.3.1</annotation-api.version> + <annotation-api.version>1.3.2</annotation-api.version> </properties> <modules> <module>abstract-factory</module> @@ -320,6 +320,11 @@ <artifactId>jaxb-impl</artifactId> <version>${jaxb-impl.version}</version> </dependency> + <dependency> + <groupId>org.javassist</groupId> + <artifactId>javassist</artifactId> + <version>3.25.0-GA</version> + </dependency> </dependencies> </dependencyManagement> @@ -380,8 +385,8 @@ <artifactId>maven-compiler-plugin</artifactId> <version>${compiler.version}</version> <configuration> - <source>1.8</source> - <target>1.8</target> + <source>11</source> + <target>11</target> </configuration> </plugin> <plugin> @@ -500,27 +505,4 @@ </plugins> </reporting> - <profiles> - <profile> - <id>jdk11-dep-management</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencyManagement> - <dependencies> - <dependency> - <groupId>org.javassist</groupId> - <artifactId>javassist</artifactId> - <version>3.25.0-GA</version> - </dependency> - <dependency> - <groupId>javax.annotation</groupId> - <artifactId>javax.annotation-api</artifactId> - <version>1.3.2</version> - </dependency> - </dependencies> - </dependencyManagement> - </profile> - </profiles> - </project> diff --git a/service-layer/pom.xml b/service-layer/pom.xml index 4edd950740a8..057a701341a7 100644 --- a/service-layer/pom.xml +++ b/service-layer/pom.xml @@ -41,6 +41,14 @@ <groupId>com.h2database</groupId> <artifactId>h2</artifactId> </dependency> + <dependency> + <groupId>com.sun.xml.bind</groupId> + <artifactId>jaxb-impl</artifactId> + </dependency> + <dependency> + <groupId>javax.xml.bind</groupId> + <artifactId>jaxb-api</artifactId> + </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> @@ -52,22 +60,5 @@ <scope>test</scope> </dependency> </dependencies> - <profiles> - <profile> - <id>jdk11-deps</id> - <activation> - <jdk>[11,)</jdk> - </activation> - <dependencies> - <dependency> - <groupId>com.sun.xml.bind</groupId> - <artifactId>jaxb-impl</artifactId> - </dependency> - <dependency> - <groupId>javax.xml.bind</groupId> - <artifactId>jaxb-api</artifactId> - </dependency> - </dependencies> - </profile> - </profiles> + </project>

train

train

iluwatar

train

iluwatar/java-design-patterns/413_986

iluwatar/java-design-patterns

iluwatar/java-design-patterns/413

iluwatar/java-design-patterns/986

088bb764f35ec5d37e58ef1eb66bfce80378db5d

7e698a90dd7664e119ec0b082883ea48dc12ae2e

Circuit Breaker pattern

http://martinfowler.com/bliki/CircuitBreaker.html The basic idea behind the circuit breaker is very simple. You wrap a protected function call in a circuit breaker object, which monitors for failures. Once the failures reach a certain threshold, the circuit breaker trips, and all further calls to the circuit breaker return with an error, without the protected call being made at all. Usually you'll also want some kind of monitor alert if the circuit breaker trips. A production ready implementation of pattern can be found here. https://github.com/Comcast/jrugged/blob/master/jrugged-core/src/main/java/org/fishwife/jrugged/CircuitBreaker.java

diff --git a/circuit-breaker/README.md b/circuit-breaker/README.md new file mode 100644 index 000000000000..db75ca58c0d0 --- /dev/null +++ b/circuit-breaker/README.md @@ -0,0 +1,188 @@ +--- +layout: pattern +title: CircuitBreaker +folder: circuit-breaker +permalink: /patterns/circuit-breaker/ +categories: Other +tags: + - Java + - Performance + - Difficulty-Intermediate +--- + +## Intent + +Handle costly remote *procedure/service* calls in such a way that the failure of a **single** service/component cannot bring the whole application down, and we can reconnect to the service as soon as possible. + +## Explanation + +Real world example + +> Imagine a Web App that has both local (example: files and images) and remote (example: database entries) to serve. The database might not be responding due to a variety of reasons, so if the application keeps trying to read from the database using multiple threads/processes, soon all of them will hang and our entire web application will crash. We should be able to detect this situation and show the user an appropriate message so that he/she can explore other parts of the app unaffected by the database failure without any problem. + +In plain words + +> Allows us to save resources when we know a remote service failed. Useful when all parts of our application are highly decoupled from each other, and failure of one component doesn't mean the other parts will stop working. + +Wikipedia says + +> **Circuit breaker** is a design pattern used in modern software development. It is used to detect failures and encapsulates the logic of preventing a failure from constantly recurring, during maintenance, temporary external system failure or unexpected system difficulties. + +So, how does this all come together? + +## Programmatic Example +With the above example in mind we will imitate the functionality in a simple manner. We have two services: A *monitoring service* which will mimic the web app and will make both **local** and **remote** calls. + +The service architecture is as follows: + + + +In terms of code, the End user application is: + +```java +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + public static void main(String[] args) { + var obj = new MonitoringService(); + var circuitBreaker = new CircuitBreaker(3000, 1, 2000 * 1000 * 1000); + var serverStartTime = System.nanoTime(); + while (true) { + LOGGER.info(obj.localResourceResponse()); + LOGGER.info(obj.remoteResourceResponse(circuitBreaker, serverStartTime)); + LOGGER.info(circuitBreaker.getState()); + try { + Thread.sleep(5 * 1000); + } catch (InterruptedException e) { + LOGGER.error(e.getMessage()); + } + } + } +} +``` + +The monitoring service is: + +``` java +public class MonitoringService { + + public String localResourceResponse() { + return "Local Service is working"; + } + + public String remoteResourceResponse(CircuitBreaker circuitBreaker, long serverStartTime) { + try { + return circuitBreaker.call("delayedService", serverStartTime); + } catch (Exception e) { + return e.getMessage(); + } + } +} +``` +As it can be seen, it does the call to get local resources directly, but it wraps the call to remote (costly) service in a circuit breaker object, which prevents faults as follows: + +```java +public class CircuitBreaker { + private final long timeout; + private final long retryTimePeriod; + long lastFailureTime; + int failureCount; + private final int failureThreshold; + private State state; + private final long futureTime = 1000 * 1000 * 1000 * 1000; + + CircuitBreaker(long timeout, int failureThreshold, long retryTimePeriod) { + this.state = State.CLOSED; + this.failureThreshold = failureThreshold; + this.timeout = timeout; + this.retryTimePeriod = retryTimePeriod; + this.lastFailureTime = System.nanoTime() + futureTime; + this.failureCount = 0; + } + + private void reset() { + this.failureCount = 0; + this.lastFailureTime = System.nanoTime() + futureTime; + this.state = State.CLOSED; + } + + private void recordFailure() { + failureCount = failureCount + 1; + this.lastFailureTime = System.nanoTime(); + } + + protected void setState() { + if (failureCount > failureThreshold) { + if ((System.nanoTime() - lastFailureTime) > retryTimePeriod) { + state = State.HALF_OPEN; + } else { + state = State.OPEN; + } + } else { + state = State.CLOSED; + } + } + + public String getState() { + return state.name(); + } + + public void setStateForBypass(State state) { + this.state = state; + } + + public String call(String serviceToCall, long serverStartTime) throws Exception { + setState(); + if (state == State.OPEN) { + return "This is stale response from API"; + } else { + if (serviceToCall.equals("delayedService")) { + var delayedService = new DelayedService(20); + var response = delayedService.response(serverStartTime); + if (response.split(" ")[3].equals("working")) { + reset(); + return response; + } else { + recordFailure(); + throw new Exception("Remote service not responding"); + } + } else { + throw new Exception("Unknown Service Name"); + } + } + } +} +``` + +How does the above pattern prevent failures? Let's understand via this finite state machine implemented by it. + + + +- We initialize the Circuit Breaker object with certain parameters: **timeout**, **failureThreshold** and **retryTimePeriod** which help determine how resilient the API is. +- Initially, we are in the **closed** state and the remote call to API happens. +- Every time the call succeeds, we reset the state to as it was in the beginning. +- If the number of failures cross a certain threshold, we move to the **open** state, which acts just like an open circuit and prevents remote service calls from being made, thus saving resources. (Here, we return the response called ```stale response from API```) +- Once we exceed the retry timeout period, we move to the **half-open** state and make another call to the remote service again to check if the service is working so that we can serve fresh content. A *failure* sets it back to **open** state and another attempt is made after retry timeout period, while a *success* sets it to **closed** state so that everything starts working normally again. + + +## Applicability +Use the Circuit Breaker pattern when + +- Building a fault-tolerant application where failure of some services shouldn't bring the entire application down. +- Building an continuously incremental/continuous delivery application, as some of it's components can be upgraded without shutting it down entirely. + +## Related Patterns + +- [Retry Pattern](https://github.com/iluwatar/java-design-patterns/tree/master/retry) + +## Real world examples +* [Spring Circuit Breaker module](https://spring.io/guides/gs/circuit-breaker) +* [Netflix Hystrix API](https://github.com/Netflix/Hystrix) + +## Credits + +* [Understanding Circuit Breaker Pattern](https://itnext.io/understand-circuitbreaker-design-pattern-with-simple-practical-example-92a752615b42) +* [Martin Fowler on Circuit Breaker](https://martinfowler.com/bliki/CircuitBreaker.html) +* [Fault tolerance in a high volume, distributed system](https://medium.com/netflix-techblog/fault-tolerance-in-a-high-volume-distributed-system-91ab4faae74a) +* [Microsoft docs](https://docs.microsoft.com/en-us/azure/architecture/patterns/circuit-breaker) diff --git a/circuit-breaker/pom.xml b/circuit-breaker/pom.xml new file mode 100644 index 000000000000..b6587b061f7a --- /dev/null +++ b/circuit-breaker/pom.xml @@ -0,0 +1,40 @@ +<!-- + + The MIT License + Copyright (c) 2014 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.22.0-SNAPSHOT</version> + </parent> + <artifactId>circuit-breaker</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + </dependencies> +</project> diff --git a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/App.java b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/App.java new file mode 100644 index 000000000000..d1d361b16063 --- /dev/null +++ b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/App.java @@ -0,0 +1,86 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * <p> + * The intention of the Circuit Builder pattern is to handle remote failures + * robustly, which is to mean that if a service is dependant on n number of + * other services, and m of them fail, we should be able to recover from that + * failure by ensuring that the user can still use the services that are actually + * functional, and resources are not tied up by uselessly by the services which + * are not working. However, we should also be able to detect when any of the m + * failing services become operational again, so that we can use it + * </p> + * <p> + * In this example, the circuit breaker pattern is demonstrated by using two services: + * {@link MonitoringService} and {@link DelayedService}. The monitoring service + * is responsible for calling two services: a local service and a remote service {@link DelayedService} + * , and by using the circuit breaker construction we ensure that if the call to + * remote service is going to fail, we are going to save our resources and not make the + * function call at all, by wrapping our call to the remote service in the circuit + * breaker object. + * </p> + * <p> + * This works as follows: The {@link CircuitBreaker} object can be in one of three + * states: <b>Open</b>, <b>Closed</b> and <b>Half-Open</b>, which represents the real + * world circuits. If the state is closed (initial), we assume everything is alright + * and perform the function call. However, every time the call fails, we note it + * and once it crosses a threshold, we set the state to Open, preventing any further + * calls to the remote server. Then, after a certain retry period (during which we + * expect thee service to recover), we make another call to the remote server and + * this state is called the Half-Open state, where it stays till the service is down, + * and once it recovers, it goes back to the closed state and the cycle continues. + * </p> + */ +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + /** + * Program entry point + * + * @param args command line args + */ + public static void main(String[] args) { + //Create an object of monitoring service which makes both local and remote calls + var obj = new MonitoringService(); + //Set the circuit Breaker parameters + var circuitBreaker = new CircuitBreaker(3000, 1, 2000 * 1000 * 1000); + var serverStartTime = System.nanoTime(); + while (true) { + LOGGER.info(obj.localResourceResponse()); + LOGGER.info(obj.remoteResourceResponse(circuitBreaker, serverStartTime)); + LOGGER.info(circuitBreaker.getState()); + try { + Thread.sleep(5 * 1000); + } catch (InterruptedException e) { + LOGGER.error(e.getMessage()); + } + } + } +} diff --git a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/CircuitBreaker.java b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/CircuitBreaker.java new file mode 100644 index 000000000000..ad014f9fdae0 --- /dev/null +++ b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/CircuitBreaker.java @@ -0,0 +1,128 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +/** + * The circuit breaker class with all configurations + */ +public class CircuitBreaker { + private final long timeout; + private final long retryTimePeriod; + long lastFailureTime; + int failureCount; + private final int failureThreshold; + private State state; + private final long futureTime = 1000 * 1000 * 1000 * 1000; + + /** + * Constructor to create an instance of Circuit Breaker + * @param timeout Timeout for the API request. Not necessary for this simple example + * @param failureThreshold Number of failures we receive from the depended service before changing state to 'OPEN' + * @param retryTimePeriod Time period after which a new request is made to remote service for status check. + */ + CircuitBreaker(long timeout, int failureThreshold, long retryTimePeriod) { + // We start in a closed state hoping that everything is fine + this.state = State.CLOSED; + this.failureThreshold = failureThreshold; + // Timeout for the API request. Used to break the calls made to remote resource if it exceeds the limit + this.timeout = timeout; + this.retryTimePeriod = retryTimePeriod; + //An absurd amount of time in future which basically indicates the last failure never happened + this.lastFailureTime = System.nanoTime() + futureTime; + this.failureCount = 0; + } + + //Reset everything to defaults + private void reset() { + this.failureCount = 0; + this.lastFailureTime = System.nanoTime() + futureTime; + this.state = State.CLOSED; + } + + private void recordFailure() { + failureCount = failureCount + 1; + this.lastFailureTime = System.nanoTime(); + } + + protected void setState() { + if (failureCount > failureThreshold) { //Then something is wrong with remote service + if ((System.nanoTime() - lastFailureTime) > retryTimePeriod) { + //We have waited long enough and should try checking if service is up + state = State.HALF_OPEN; + } else { + //Service would still probably be down + state = State.OPEN; + } + } else { + //Everything is working fine + state = State.CLOSED; + } + } + + public String getState() { + return state.name(); + } + + /** + * Break the circuit beforehand if it is known service is down + * Or connect the circuit manually if service comes online before expected + * @param state State at which circuit is in + */ + public void setStateForBypass(State state) { + this.state = state; + } + + /** + * @param serviceToCall The name of the service in String. Can be changed to data URLs in case of web applications + * @param serverStartTime Time at which actual server was started which makes calls to this service + * @return Value from the remote resource, stale response or a custom exception + */ + public String call(String serviceToCall, long serverStartTime) throws Exception { + setState(); + if (state == State.OPEN) { + // return cached response if no the circuit is in OPEN state + return "This is stale response from API"; + } else { + // Make the API request if the circuit is not OPEN + if (serviceToCall.equals("delayedService")) { + var delayedService = new DelayedService(20); + var response = delayedService.response(serverStartTime); + //In a real application, this would be run in a thread and the timeout + //parameter of the circuit breaker would be utilized to know if service + //is working. Here, we simulate that based on server response itself + if (response.split(" ")[3].equals("working")) { + // Yay!! the API responded fine. Let's reset everything. + reset(); + return response; + } else { + // Uh-oh!! the call still failed. Let's update that in our records. + recordFailure(); + throw new Exception("Remote service not responding"); + } + } else { + throw new Exception("Unknown Service Name"); + } + } + } +} \ No newline at end of file diff --git a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DelayedService.java b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DelayedService.java new file mode 100644 index 000000000000..33217b8e721b --- /dev/null +++ b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DelayedService.java @@ -0,0 +1,61 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.circuitbreaker; + +/** +* This simulates the remote service +* It responds only after a certain timeout period (default set to 20 seconds) +*/ +public class DelayedService { + private final int delay; + + /** + * Constructor to create an instance of DelayedService, which is down for first few seconds + * @param delay the delay after which service would behave properly, in seconds + */ + public DelayedService(int delay) { + this.delay = delay; + } + + public DelayedService() { + this.delay = 60; + } + + /** + * @param serverStartTime Time at which actual server was started which makes calls to this service + * @return The state of the service + */ + public String response(long serverStartTime) { + var currentTime = System.nanoTime(); + //Since currentTime and serverStartTime are both in nanoseconds, we convert it to + //seconds by diving by 10e9 and ensure floating point division by multiplying it + //with 1.0 first. We then check if it is greater or less than specified delay and then + //send the reply + if ((currentTime - serverStartTime) * 1.0 / (1000 * 1000 * 1000) < delay) { + //Can use Thread.sleep() here to block and simulate a hung server + return "Delayed service is down"; + } else { + return "Delayed service is working"; + } + } +} diff --git a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/MonitoringService.java b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/MonitoringService.java new file mode 100644 index 000000000000..e301ff3ca52b --- /dev/null +++ b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/MonitoringService.java @@ -0,0 +1,50 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +/** + * The service class which makes local and remote calls + * Uses {@link CircuitBreaker} object to ensure remote calls don't use up resources + */ +public class MonitoringService { + + //Assumption: Local service won't fail, no need to wrap it in a circuit breaker logic + public String localResourceResponse() { + return "Local Service is working"; + } + + /** + * Try to get result from remote server + * @param circuitBreaker The circuitBreaker object with all parameters + * @param serverStartTime Time at which actual server was started which makes calls to this service + * @return result from the remote response or exception raised by it. + */ + public String remoteResourceResponse(CircuitBreaker circuitBreaker, long serverStartTime) { + try { + return circuitBreaker.call("delayedService", serverStartTime); + } catch (Exception e) { + return e.getMessage(); + } + } +} \ No newline at end of file diff --git a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/State.java b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/State.java new file mode 100644 index 000000000000..87982153ccd0 --- /dev/null +++ b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/State.java @@ -0,0 +1,33 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +/** + * Enumeration for states the circuit breaker could be in + */ +public enum State { + CLOSED, + OPEN, + HALF_OPEN +} \ No newline at end of file diff --git a/pom.xml b/pom.xml index 50e7c7de5439..9e61e716b864 100644 --- a/pom.xml +++ b/pom.xml @@ -181,6 +181,7 @@ <module>bytecode</module> <module>leader-election</module> <module>data-locality</module> + <module>circuit-breaker</module> </modules>

diff --git a/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/CircuitBreakerTest.java b/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/CircuitBreakerTest.java new file mode 100644 index 000000000000..5780e9355c58 --- /dev/null +++ b/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/CircuitBreakerTest.java @@ -0,0 +1,80 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import org.junit.jupiter.api.Test; + +/** + * + * Circuit Breaker test + * + */ +public class CircuitBreakerTest { + + //long timeout, int failureThreshold, long retryTimePeriod + @Test + public void testSetState() { + var circuitBreaker = new CircuitBreaker(1,1,100); + //Right now, failureCount<failureThreshold, so state should be closed + assertEquals(circuitBreaker.getState(), "CLOSED"); + circuitBreaker.failureCount = 4; + circuitBreaker.lastFailureTime = System.nanoTime(); + circuitBreaker.setState(); + //Since failureCount>failureThreshold, and lastFailureTime is nearly equal to current time, + //state should be half-open + assertEquals(circuitBreaker.getState(), "HALF_OPEN"); + //Since failureCount>failureThreshold, and lastFailureTime is much lesser current time, + //state should be open + circuitBreaker.lastFailureTime = System.nanoTime() - 1000 * 1000 * 1000 * 1000; + circuitBreaker.setState(); + assertEquals(circuitBreaker.getState(), "OPEN"); + //Now set it back again to closed to test idempotency + circuitBreaker.failureCount = 0; + circuitBreaker.setState(); + assertEquals(circuitBreaker.getState(), "CLOSED"); + } + + @Test + public void testSetStateForBypass() { + var circuitBreaker = new CircuitBreaker(1,1,100); + //Right now, failureCount<failureThreshold, so state should be closed + //Bypass it and set it to open + circuitBreaker.setStateForBypass(State.OPEN); + assertEquals(circuitBreaker.getState(), "OPEN"); + } + + @Test + public void testApiResponses() { + var circuitBreaker = new CircuitBreaker(1,1,100); + try { + //Call with the paramater start_time set to huge amount of time in past so that service + //replies with "Ok". Also, state is CLOSED in start + var response = circuitBreaker.call("delayedService", System.nanoTime() - 60 * 1000 * 1000 * 1000); + assertEquals(response, "Delayed service is working"); + } catch (Exception e) { + System.out.println(e.getMessage()); + } + } +} diff --git a/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/DelayedServiceTest.java b/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/DelayedServiceTest.java new file mode 100644 index 000000000000..7b9c33795144 --- /dev/null +++ b/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/DelayedServiceTest.java @@ -0,0 +1,42 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import org.junit.jupiter.api.Test; + +/** + * + * Monitoring Service test + * + */ +public class DelayedServiceTest { + + //Improves code coverage + @Test + public void testDefaultConstructor() { + var obj = new DelayedService(); + assertEquals(obj.response(System.nanoTime()), "Delayed service is down"); + } +} diff --git a/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/MonitoringServiceTest.java b/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/MonitoringServiceTest.java new file mode 100644 index 000000000000..280da63e5e91 --- /dev/null +++ b/circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/MonitoringServiceTest.java @@ -0,0 +1,63 @@ +/** + * The MIT License + * Copyright (c) 2014 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.circuitbreaker; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import org.junit.jupiter.api.Test; + +/** + * + * Monitoring Service test + * + */ +public class MonitoringServiceTest { + + //long timeout, int failureThreshold, long retryTimePeriod + @Test + public void testLocalResponse() { + var monitoringService = new MonitoringService(); + var response = monitoringService.localResourceResponse(); + assertEquals(response, "Local Service is working"); + } + + @Test + public void testRemoteResponse() { + var monitoringService = new MonitoringService(); + var circuitBreaker = new CircuitBreaker(1,1,100); + //Set time in past to make the server work + var serverStartTime = System.nanoTime() / 10; + var response = monitoringService.remoteResourceResponse(circuitBreaker, serverStartTime); + assertEquals(response, "Delayed service is working"); + } + + @Test + public void testRemoteResponse2() { + MonitoringService monitoringService = new MonitoringService(); + CircuitBreaker circuitBreaker = new CircuitBreaker(1,1,100); + //Set time as current time as initially server fails + long serverStartTime = System.nanoTime(); + String response = monitoringService.remoteResourceResponse(circuitBreaker, serverStartTime); + assertEquals(response, "Remote service not responding"); + } +}

test

train

npathai

train

iluwatar/java-design-patterns/988_992

iluwatar/java-design-patterns

iluwatar/java-design-patterns/988

iluwatar/java-design-patterns/992

9ebbc421dd96b84c50808ca8ac4a520042e73b8f

7de53f9853d575c7a341eefeac77949e6d660349

Java 11 support: HttpClient

This task is part of the Java 11 transition plan https://github.com/iluwatar/java-design-patterns/wiki/16.-Java-11-Transition Patterns Aggregator Microservices and API Gateway are currently using Apache HttpClient in their implementation. Java 11 provides its own HttpClient and we should switch to that instead to get rid of unnecessary external dependencies. Links: https://winterbe.com/posts/2018/09/24/java-11-tutorial/#http-client

diff --git a/aggregator-microservices/aggregator-service/pom.xml b/aggregator-microservices/aggregator-service/pom.xml index 6ad8c3c8c5a4..f1ea05a6ec4d 100644 --- a/aggregator-microservices/aggregator-service/pom.xml +++ b/aggregator-microservices/aggregator-service/pom.xml @@ -53,10 +53,6 @@ <artifactId>mockito-core</artifactId> <scope>test</scope> </dependency> - <dependency> - <groupId>org.apache.httpcomponents</groupId> - <artifactId>httpclient</artifactId> - </dependency> </dependencies> <build> diff --git a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java index 131fbf8695cd..c731a695d2a3 100644 --- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java +++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java @@ -22,18 +22,16 @@ */ package com.iluwatar.aggregator.microservices; -import org.apache.http.client.ClientProtocolException; -import org.apache.http.client.methods.CloseableHttpResponse; -import org.apache.http.client.methods.HttpGet; -import org.apache.http.impl.client.CloseableHttpClient; -import org.apache.http.impl.client.HttpClients; -import org.apache.http.util.EntityUtils; +import java.io.IOException; +import java.net.URI; +import java.net.http.HttpClient; +import java.net.http.HttpRequest; +import java.net.http.HttpResponse; + import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; -import java.io.IOException; - /** * An adapter to communicate with information micro-service. */ @@ -45,16 +43,17 @@ public class ProductInformationClientImpl implements ProductInformationClient { @Override public String getProductTitle() { String response = null; - try (CloseableHttpClient httpClient = HttpClients.createDefault()) { - HttpGet httpGet = new HttpGet("http://localhost:51515/information"); - try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) { - response = EntityUtils.toString(httpResponse.getEntity()); - } - } catch (ClientProtocolException cpe) { - LOGGER.error("ClientProtocolException Occured", cpe); + HttpRequest request = + HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:51515/information")).build(); + HttpClient client = HttpClient.newHttpClient(); + try { + HttpResponse<String> httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString()); + response = httpResponse.body(); } catch (IOException ioe) { - LOGGER.error("IOException Occurred", ioe); - } + LOGGER.error("IOException Occurred", ioe); + } catch (InterruptedException ie) { + LOGGER.error("InterruptedException Occurred", ie); + } return response; } } diff --git a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java index 780dccb78e20..7e855fffe149 100644 --- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java +++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java @@ -22,39 +22,39 @@ */ package com.iluwatar.aggregator.microservices; -import org.apache.http.client.ClientProtocolException; -import org.apache.http.client.methods.CloseableHttpResponse; -import org.apache.http.client.methods.HttpGet; -import org.apache.http.impl.client.CloseableHttpClient; -import org.apache.http.impl.client.HttpClients; -import org.apache.http.util.EntityUtils; +import java.io.IOException; +import java.net.URI; +import java.net.http.HttpClient; +import java.net.http.HttpRequest; +import java.net.http.HttpResponse; + import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; -import java.io.IOException; - /** * An adapter to communicate with inventory micro-service. */ @Component public class ProductInventoryClientImpl implements ProductInventoryClient { - private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class); + private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class); - @Override - public int getProductInventories() { - String response = "0"; - try (CloseableHttpClient httpClient = HttpClients.createDefault()) { - HttpGet httpGet = new HttpGet("http://localhost:51516/inventories"); - try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) { - response = EntityUtils.toString(httpResponse.getEntity()); - } - } catch (ClientProtocolException cpe) { - LOGGER.error("ClientProtocolException Occured", cpe); - } catch (IOException ioe) { - LOGGER.error("IOException Occurred", ioe); - } - return Integer.parseInt(response); - } + @Override + public int getProductInventories() { + String response = "0"; + + HttpRequest request = + HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:51516/inventories")).build(); + HttpClient client = HttpClient.newHttpClient(); + try { + HttpResponse<String> httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString()); + response = httpResponse.body(); + } catch (IOException ioe) { + LOGGER.error("IOException Occurred", ioe); + } catch (InterruptedException ie) { + LOGGER.error("InterruptedException Occurred", ie); + } + return Integer.parseInt(response); + } } diff --git a/api-gateway/api-gateway-service/pom.xml b/api-gateway/api-gateway-service/pom.xml index 44a8bde37923..fdea5c2a4993 100644 --- a/api-gateway/api-gateway-service/pom.xml +++ b/api-gateway/api-gateway-service/pom.xml @@ -39,10 +39,6 @@ <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> </dependency> - <dependency> - <groupId>org.apache.httpcomponents</groupId> - <artifactId>httpclient</artifactId> - </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> diff --git a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java index ebabfe839b69..63dd270e965f 100644 --- a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java +++ b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java @@ -22,35 +22,42 @@ */ package com.iluwatar.api.gateway; -import org.apache.http.client.methods.CloseableHttpResponse; -import org.apache.http.client.methods.HttpGet; -import org.apache.http.impl.client.CloseableHttpClient; -import org.apache.http.impl.client.HttpClients; -import org.apache.http.util.EntityUtils; -import org.springframework.stereotype.Component; - import java.io.IOException; +import java.net.URI; +import java.net.http.HttpClient; +import java.net.http.HttpRequest; +import java.net.http.HttpResponse; +import java.net.http.HttpResponse.BodyHandlers; + +import org.springframework.stereotype.Component; /** * An adapter to communicate with the Image microservice */ @Component public class ImageClientImpl implements ImageClient { - /** - * Makes a simple HTTP Get request to the Image microservice - * @return The path to the image - */ - @Override - public String getImagePath() { - String response = null; - try (CloseableHttpClient httpClient = HttpClients.createDefault()) { - HttpGet httpGet = new HttpGet("http://localhost:50005/image-path"); - try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) { - response = EntityUtils.toString(httpResponse.getEntity()); - } - } catch (IOException e) { - e.printStackTrace(); - } - return response; - } + /** + * Makes a simple HTTP Get request to the Image microservice + * @return The path to the image + */ + @Override + public String getImagePath() { + String response = null; + + HttpClient httpClient = + HttpClient.newHttpClient(); + HttpRequest httpGet = + HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:50005/image-path")).build(); + + try { + HttpResponse<String> httpResponse = httpClient.send(httpGet, BodyHandlers.ofString()); + response = httpResponse.body(); + } catch (IOException e) { + e.printStackTrace(); + } catch (InterruptedException e) { + e.printStackTrace(); + } + + return response; + } } diff --git a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java index 87f44761c649..e8ef38bff3b2 100644 --- a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java +++ b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java @@ -22,35 +22,43 @@ */ package com.iluwatar.api.gateway; -import org.apache.http.client.methods.CloseableHttpResponse; -import org.apache.http.client.methods.HttpGet; -import org.apache.http.impl.client.CloseableHttpClient; -import org.apache.http.impl.client.HttpClients; -import org.apache.http.util.EntityUtils; -import org.springframework.stereotype.Component; - import java.io.IOException; +import java.net.URI; +import java.net.http.HttpClient; +import java.net.http.HttpRequest; +import java.net.http.HttpResponse; +import java.net.http.HttpResponse.BodyHandlers; + +import org.springframework.stereotype.Component; /** * An adapter to communicate with the Price microservice */ @Component public class PriceClientImpl implements PriceClient { - /** - * Makes a simple HTTP Get request to the Price microservice - * @return The price of the product - */ - @Override - public String getPrice() { - String response = null; - try (CloseableHttpClient httpClient = HttpClients.createDefault()) { - HttpGet httpGet = new HttpGet("http://localhost:50006/price"); - try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) { - response = EntityUtils.toString(httpResponse.getEntity()); - } - } catch (IOException e) { - e.printStackTrace(); - } - return response; - } + /** + * Makes a simple HTTP Get request to the Price microservice + * @return The price of the product + */ + @Override + public String getPrice() { + + String response = null; + + HttpClient httpClient = + HttpClient.newHttpClient(); + HttpRequest httpGet = + HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:50006/price")).build(); + + try { + HttpResponse<String> httpResponse = httpClient.send(httpGet, BodyHandlers.ofString()); + response = httpResponse.body(); + } catch (IOException e) { + e.printStackTrace(); + } catch (InterruptedException e) { + e.printStackTrace(); + } + + return response; + } } diff --git a/pom.xml b/pom.xml index 9b4672fb3b6e..80b0b3e706e8 100644 --- a/pom.xml +++ b/pom.xml @@ -43,7 +43,6 @@ <camel.version>2.24.0</camel.version> <guava.version>19.0</guava.version> <mockito.version>1.10.19</mockito.version> - <apache-httpcomponents.version>4.5.10</apache-httpcomponents.version> <htmlunit.version>2.22</htmlunit.version> <guice.version>4.0</guice.version> <mongo-java-driver.version>3.3.0</mongo-java-driver.version> @@ -212,11 +211,6 @@ <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> - <dependency> - <groupId>org.apache.httpcomponents</groupId> - <artifactId>httpclient</artifactId> - <version>${apache-httpcomponents.version}</version> - </dependency> <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId>

test

train

iluwatar

train

iluwatar/java-design-patterns/996_997

iluwatar/java-design-patterns

iluwatar/java-design-patterns/996

iluwatar/java-design-patterns/997

9ebbc421dd96b84c50808ca8ac4a520042e73b8f

72b174619fa8f936bff553ef19e741f4a11efb6c

Sonar analysis in master branch is failing


diff --git a/.sonarcloud.properties b/.sonarcloud.properties deleted file mode 100644 index c6b26bf5df8b..000000000000 --- a/.sonarcloud.properties +++ /dev/null @@ -1,38 +0,0 @@ -# -# The MIT License -# Copyright © 2014-2019 Ilkka Seppälä -# -# Permission is hereby granted, free of charge, to any person obtaining a copy -# of this software and associated documentation files (the "Software"), to deal -# in the Software without restriction, including without limitation the rights -# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -# copies of the Software, and to permit persons to whom the Software is -# furnished to do so, subject to the following conditions: -# -# The above copyright notice and this permission notice shall be included in -# all copies or substantial portions of the Software. -# -# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN -# THE SOFTWARE. -# - -# Path to sources -#sonar.sources=. -#sonar.exclusions= -#sonar.inclusions= - -# Path to tests -#sonar.tests= -#sonar.test.exclusions= -#sonar.test.inclusions= - -# Source encoding -#sonar.sourceEncoding=UTF-8 - -# Exclusions for copy-paste detection -#sonar.cpd.exclusions= diff --git a/.travis.yml b/.travis.yml index 45323dcfd457..6cd971428327 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,23 +1,27 @@ language: java -dist: xenial +dist: bionic jdk: - openjdk11 +sudo: required env: global: - GH_REF: github.com/iluwatar/java-design-patterns.git - secure: LxTDuNS/rBWIvKkaEqr79ImZAe48mCdoYCF41coxNXgNoippo4GIBArknqtv+XvdkiuRZ1yGyj6pn8GU33c/yn+krddTUkVCwTbVatbalW5jhQjDbHYym/JcxaK9ZS/3JTeGcWrBgiPqHEEDhCf26vPZsXoMSeVCEORVKTp1BSg= - - secure: "eoWlW9GyTJY04P8K3pxayXwU9/hmptQg/LfirispQkV9YvmziCfSzXnatnBhNfud98sCzY8BScXnb+OWLTnjLKpId4rtEqb0aJ40Jc32cUKzgzFAUn7cNcDAbUIfyPAGVqyQqfj/11wYSADwWMMOPlW97ExUtoyiH2WenXuRHso=" services: - xvfb -# default install command is just "mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V" -install: -- mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -e +addons: + sonarcloud: + organization: "iluwatar" + token: + secure: "FpHwMYPMkdWU6CeIB7+O3qIeIM4vJMp47UjkKK53f0w0s6tPZofZZkab+gcL2TqKSil7sFVB/AQXU1cUubflRszwcLbNsc8H2yFehD79o0o0Mqd1Dd5ip/q0KQbHkkln+InFlVLfvrLB4Xd4mlQVxbGhqpULBhXjKzFzQlRFcuU=" +script: + # the following command line builds the project, runs the tests with coverage and then execute the SonarCloud analysis + - mvn clean verify sonar:sonar -Dsonar.projectKey=iluwatar_java-design-patterns after_success: -- mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarcloud.io -Dsonar.login=$SONAR_TOKEN - bash update-ghpages.sh notifications: @@ -29,5 +33,3 @@ notifications: on_success: change # options: [always|never|change] default: always on_failure: always # options: [always|never|change] default: always on_start: never # options: [always|never|change] default: always - -sudo: required diff --git a/pom.xml b/pom.xml index 4ed357181a12..d6cd3a6e60c3 100644 --- a/pom.xml +++ b/pom.xml @@ -353,37 +353,6 @@ <build> <pluginManagement> <plugins> - <!-- This plugin's configuration is used to store Eclipse m2e settings - only. It has no influence on the Maven build itself. TODO: Remove when the - m2e plugin can correctly bind to Maven lifecycle --> - <plugin> - <groupId>org.eclipse.m2e</groupId> - <artifactId>lifecycle-mapping</artifactId> - <version>1.0.0</version> - <configuration> - <lifecycleMappingMetadata> - <pluginExecutions> - <pluginExecution> - <pluginExecutionFilter> - <groupId>org.jacoco</groupId> - <artifactId> - jacoco-maven-plugin - </artifactId> - <versionRange> - [0.6.2,) - </versionRange> - <goals> - <goal>prepare-agent</goal> - </goals> - </pluginExecutionFilter> - <action> - <ignore/> - </action> - </pluginExecution> - </pluginExecutions> - </lifecycleMappingMetadata> - </configuration> - </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> @@ -410,20 +379,6 @@ </pluginManagement> <plugins> - <plugin> - <groupId>org.jacoco</groupId> - <artifactId>jacoco-maven-plugin</artifactId> - <version>${jacoco.version}</version> - <executions> - <execution> - <id>prepare-agent</id> - <goals> - <goal>prepare-agent</goal> - </goals> - </execution> - </executions> - </plugin> - <!--checkstyle plug-in. checking against googles styles see config at checkstyle.xml --> @@ -471,6 +426,27 @@ </execution> </executions> </plugin> + + <plugin> + <groupId>org.jacoco</groupId> + <artifactId>jacoco-maven-plugin</artifactId> + <version>${jacoco.version}</version> + <executions> + <execution> + <id>prepare-agent</id> + <goals> + <goal>prepare-agent</goal> + </goals> + </execution> + <execution> + <id>report</id> + <goals> + <goal>report</goal> + </goals> + </execution> + </executions> + </plugin> + </plugins> </build>

val

train

iluwatar

train

iluwatar/java-design-patterns/554_998

iluwatar/java-design-patterns

iluwatar/java-design-patterns/554

iluwatar/java-design-patterns/998

7e698a90dd7664e119ec0b082883ea48dc12ae2e

a5646b63c19455051fb49fd5a455a28159708d49

Subclass Sandbox pattern

http://gameprogrammingpatterns.com/subclass-sandbox.html

diff --git a/pom.xml b/pom.xml index 9e61e716b864..36d501a92054 100644 --- a/pom.xml +++ b/pom.xml @@ -61,6 +61,7 @@ <jaxb-api.version>2.3.1</jaxb-api.version> <jaxb-impl.version>2.3.2</jaxb-impl.version> <annotation-api.version>1.3.2</annotation-api.version> + <system-rules.version>1.19.0</system-rules.version> </properties> <modules> <module>abstract-factory</module> @@ -181,8 +182,8 @@ <module>bytecode</module> <module>leader-election</module> <module>data-locality</module> + <module>subclass-sandbox</module> <module>circuit-breaker</module> - </modules> <repositories> @@ -323,6 +324,12 @@ <artifactId>javassist</artifactId> <version>3.25.0-GA</version> </dependency> + <dependency> + <groupId>com.github.stefanbirkner</groupId> + <artifactId>system-rules</artifactId> + <version>${system-rules.version}</version> + <scope>test</scope> + </dependency> </dependencies> </dependencyManagement> diff --git a/subclass-sandbox/README.md b/subclass-sandbox/README.md new file mode 100644 index 000000000000..674991f0895c --- /dev/null +++ b/subclass-sandbox/README.md @@ -0,0 +1,29 @@ + +--- +layout: pattern +title: Subclass Sandbox +folder: subclass-sandbox +permalink: /patterns/subclass-sandbox/ +categories: Other +tags: + - Java + - Difficulty-Beginner +--- + +## Intent +The subclass sandbox pattern describes a basic idea, while not having a lot of detailed mechanics. You will need the pattern when you have several similar subclasses. If you have to make a tiny change, then change the base class, while all subclasses shouldn't have to be touched. So the base class has to be able to provide all of the operations a derived class needs to perform. + +## Applicability +The Subclass Sandbox pattern is a very simple, common pattern lurking in lots of codebases, even outside of games. If you have a non-virtual protected method laying around, you’re probably already using something like this. Subclass Sandbox is a good fit when: + +- You have a base class with a number of derived classes. + +- The base class is able to provide all of the operations that a derived class may need to perform. + +- There is behavioral overlap in the subclasses and you want to make it easier to share code between them. + +- You want to minimize coupling between those derived classes and the rest of the program. + +## Credits + +* [Game Programming Patterns - Subclass Sandbox]([http://gameprogrammingpatterns.com/subclass-sandbox.html](http://gameprogrammingpatterns.com/subclass-sandbox.html)) \ No newline at end of file diff --git a/subclass-sandbox/pom.xml b/subclass-sandbox/pom.xml new file mode 100644 index 000000000000..8016ba471ed0 --- /dev/null +++ b/subclass-sandbox/pom.xml @@ -0,0 +1,49 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + The MIT License + Copyright ? 2014 Ilkka Sepp?l? + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <parent> + <artifactId>java-design-patterns</artifactId> + <groupId>com.iluwatar</groupId> + <version>1.22.0-SNAPSHOT</version> + </parent> + <modelVersion>4.0.0</modelVersion> + + <artifactId>subclass-sandbox</artifactId> + + <dependencies> + <dependency> + <groupId>junit</groupId> + <artifactId>junit</artifactId> + </dependency> + <dependency> + <groupId>com.github.stefanbirkner</groupId> + <artifactId>system-rules</artifactId> + </dependency> + </dependencies> + +</project> \ No newline at end of file diff --git a/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/App.java b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/App.java new file mode 100644 index 000000000000..2e1f41c056c4 --- /dev/null +++ b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/App.java @@ -0,0 +1,53 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * The subclass sandbox pattern describes a basic idea, while not having a lot + * of detailed mechanics. You will need the pattern when you have several similar + * subclasses. If you have to make a tiny change, then change the base class, + * while all subclasses shouldn't have to be touched. So the base class has to be + * able to provide all of the operations a derived class needs to perform. + */ +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + /** + * Entry point of the main program. + * @param args Program runtime arguments. + */ + public static void main(String[] args) { + LOGGER.info("Use superpower: sky launch"); + var skyLaunch = new SkyLaunch(); + skyLaunch.activate(); + LOGGER.info("Use superpower: ground dive"); + var groundDive = new GroundDive(); + groundDive.activate(); + } + +} diff --git a/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/GroundDive.java b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/GroundDive.java new file mode 100644 index 000000000000..f284e125fba7 --- /dev/null +++ b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/GroundDive.java @@ -0,0 +1,44 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.slf4j.LoggerFactory; + +/** + * GroundDive superpower. + */ +public class GroundDive extends Superpower { + + public GroundDive() { + super(); + logger = LoggerFactory.getLogger(GroundDive.class); + } + + @Override + protected void activate() { + move(0, 0, -20); + playSound("GROUNDDIVE_SOUND", 5); + spawnParticles("GROUNDDIVE_PARTICLE", 20); + } +} diff --git a/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/SkyLaunch.java b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/SkyLaunch.java new file mode 100644 index 000000000000..16c94bd0ca57 --- /dev/null +++ b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/SkyLaunch.java @@ -0,0 +1,44 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.slf4j.LoggerFactory; + +/** + * SkyLaunch superpower. + */ +public class SkyLaunch extends Superpower { + + public SkyLaunch() { + super(); + logger = LoggerFactory.getLogger(SkyLaunch.class); + } + + @Override + protected void activate() { + move(0, 0, 20); + playSound("SKYLAUNCH_SOUND", 1); + spawnParticles("SKYLAUNCH_PARTICLE", 100); + } +} diff --git a/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/Superpower.java b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/Superpower.java new file mode 100644 index 000000000000..d4875d586d62 --- /dev/null +++ b/subclass-sandbox/src/main/java/com/iluwatar/subclasssandbox/Superpower.java @@ -0,0 +1,69 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.slf4j.Logger; + +/** + * Superpower abstract class. In this class the basic operations of all types of + * superpowers are provided as protected methods. + */ +public abstract class Superpower { + + protected Logger logger; + + /** + * Subclass of superpower should implement this sandbox method by calling the + * methods provided in this super class. + */ + protected abstract void activate(); + + /** + * Move to (x, y, z). + * @param x X coordinate. + * @param y Y coordinate. + * @param z Z coordinate. + */ + protected void move(double x, double y, double z) { + logger.info("Move to ( " + x + ", " + y + ", " + z + " )"); + } + + /** + * Play sound effect for the superpower. + * @param soundName Sound name. + * @param volumn Value of volumn. + */ + protected void playSound(String soundName, int volumn) { + logger.info("Play " + soundName + " with volumn " + volumn); + } + + /** + * Spawn particles for the superpower. + * @param particleType Particle type. + * @param count Count of particles to be spawned. + */ + protected void spawnParticles(String particleType, int count) { + logger.info("Spawn " + count + " particle with type " + particleType); + } +}

diff --git a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/AppTest.java b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/AppTest.java new file mode 100644 index 000000000000..207c71ef9ef0 --- /dev/null +++ b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/AppTest.java @@ -0,0 +1,38 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.junit.Test; + +/** + * App unit tests. + */ +public class AppTest { + + @Test + public void testMain() { + String[] args = {}; + App.main(args); + } +} diff --git a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java new file mode 100644 index 000000000000..7b4645742376 --- /dev/null +++ b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java @@ -0,0 +1,92 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.junit.Assert; +import org.junit.Rule; +import org.junit.Test; +import org.junit.contrib.java.lang.system.SystemOutRule; + +/** + * GroundDive unit tests. + */ +public class GroundDiveTest { + + @Rule + public SystemOutRule log = new SystemOutRule().enableLog(); + + @Test + public void testMove() { + log.clearLog(); + var groundDive = new GroundDive(); + groundDive.move(1.0, 1.0, 1.0); + var outputLog = getLogContent(log.getLog()); + var expectedLog = "Move to ( 1.0, 1.0, 1.0 )"; + Assert.assertEquals(outputLog, expectedLog); + } + + @Test + public void testPlaySound() { + log.clearLog(); + var groundDive = new GroundDive(); + groundDive.playSound("SOUND_NAME", 1); + var outputLog = getLogContent(log.getLog()); + var expectedLog = "Play SOUND_NAME with volumn 1"; + Assert.assertEquals(outputLog, expectedLog); + } + + @Test + public void testSpawnParticles() { + log.clearLog(); + var groundDive = new GroundDive(); + groundDive.spawnParticles("PARTICLE_TYPE", 100); + final var outputLog = getLogContent(log.getLog()); + final var expectedLog = "Spawn 100 particle with type PARTICLE_TYPE"; + Assert.assertEquals(outputLog, expectedLog); + } + + @Test + public void testActivate() { + log.clearLog(); + var groundDive = new GroundDive(); + groundDive.activate();; + String[] logs = log.getLog().split("\n"); + final var expectedSize = 3; + final var log1 = logs[0].split("-")[1].trim() + " -" + logs[0].split("-")[2].trim(); + final var expectedLog1 = "Move to ( 0.0, 0.0, -20.0 )"; + final var log2 = getLogContent(logs[1]); + final var expectedLog2 = "Play GROUNDDIVE_SOUND with volumn 5"; + final var log3 = getLogContent(logs[2]); + final var expectedLog3 = "Spawn 20 particle with type GROUNDDIVE_PARTICLE"; + Assert.assertEquals(logs.length, expectedSize); + Assert.assertEquals(log1, expectedLog1); + Assert.assertEquals(log2, expectedLog2); + Assert.assertEquals(log3, expectedLog3); + } + + private String getLogContent(String log) { + return log.split("-")[1].trim(); + } + +} diff --git a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java new file mode 100644 index 000000000000..5ba84c0b55cc --- /dev/null +++ b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java @@ -0,0 +1,91 @@ +/** + * The MIT License + * Copyright (c) 2014-2016 Ilkka Seppälä + * <p> + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * <p> + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * <p> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.subclasssandbox; + +import org.junit.Assert; +import org.junit.Rule; +import org.junit.Test; +import org.junit.contrib.java.lang.system.SystemOutRule; + +/** + * SkyLaunch unit tests. + */ +public class SkyLaunchTest { + + @Rule + public SystemOutRule log = new SystemOutRule().enableLog(); + + @Test + public void testMove() { + log.clearLog(); + var skyLaunch = new SkyLaunch(); + skyLaunch.move(1.0, 1.0, 1.0); + var outputLog = getLogContent(log.getLog()); + var expectedLog = "Move to ( 1.0, 1.0, 1.0 )"; + Assert.assertEquals(outputLog, expectedLog); + } + + @Test + public void testPlaySound() { + log.clearLog(); + var skyLaunch = new SkyLaunch(); + skyLaunch.playSound("SOUND_NAME", 1); + var outputLog = getLogContent(log.getLog()); + var expectedLog = "Play SOUND_NAME with volumn 1"; + Assert.assertEquals(outputLog, expectedLog); + } + + @Test + public void testSpawnParticles() { + log.clearLog(); + var skyLaunch = new SkyLaunch(); + skyLaunch.spawnParticles("PARTICLE_TYPE", 100); + var outputLog = getLogContent(log.getLog()); + var expectedLog = "Spawn 100 particle with type PARTICLE_TYPE"; + Assert.assertEquals(outputLog, expectedLog); + } + + @Test + public void testActivate() { + log.clearLog(); + var skyLaunch = new SkyLaunch(); + skyLaunch.activate();; + String[] logs = log.getLog().split("\n"); + final var expectedSize = 3; + final var log1 = getLogContent(logs[0]); + final var expectedLog1 = "Move to ( 0.0, 0.0, 20.0 )"; + final var log2 = getLogContent(logs[1]); + final var expectedLog2 = "Play SKYLAUNCH_SOUND with volumn 1"; + final var log3 = getLogContent(logs[2]); + final var expectedLog3 = "Spawn 100 particle with type SKYLAUNCH_PARTICLE"; + Assert.assertEquals(logs.length, expectedSize); + Assert.assertEquals(log1, expectedLog1); + Assert.assertEquals(log2, expectedLog2); + Assert.assertEquals(log3, expectedLog3); + } + + private String getLogContent(String log) { + return log.split("-")[1].trim(); + } +}

train

train

iluwatar

train

iluwatar/java-design-patterns/1001_1008

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1001

iluwatar/java-design-patterns/1008

7e698a90dd7664e119ec0b082883ea48dc12ae2e

27c131c2cb850a92b5b346b24dce20eae91cc84f

Intermittent test failure in Spatial Partition pattern


diff --git a/spatial-partition/src/main/java/com/iluwatar/spatialpartition/Rect.java b/spatial-partition/src/main/java/com/iluwatar/spatialpartition/Rect.java index 3d2f01d77d3d..71d4eda5bfa7 100644 --- a/spatial-partition/src/main/java/com/iluwatar/spatialpartition/Rect.java +++ b/spatial-partition/src/main/java/com/iluwatar/spatialpartition/Rect.java @@ -28,14 +28,14 @@ */ public class Rect { - int x; - int y; - int width; - int height; + double x; + double y; + double width; + double height; //(x,y) - centre of rectangle - Rect(int x, int y, int width, int height) { + Rect(double x, double y, double width, double height) { this.x = x; this.y = y; this.width = width;

test

train

iluwatar

train

iluwatar/java-design-patterns/1007_1015

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1007

iluwatar/java-design-patterns/1015

a5646b63c19455051fb49fd5a455a28159708d49

880b234d8fa328619e2505650849fec4c319d9fa

JUnit5 test are not able to run in Eclipse

Steps to recreate: 1. In Eclipse, select a unit test to run by right-clicking and selecting: "Run Configurations." Select a JUnit execution and ensure that the JUnit5 runner is selected:  1. Click the Run button. 1. The following error is shown:  and the following stack trace is displayed: ``` java.lang.NoClassDefFoundError: org/junit/platform/commons/PreconditionViolationException at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.createUnfilteredTest(JUnit5TestLoader.java:75) at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.createTest(JUnit5TestLoader.java:66) at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.loadTests(JUnit5TestLoader.java:53) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:525) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209) Caused by: java.lang.ClassNotFoundException: org.junit.platform.commons.PreconditionViolationException at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ... 7 more ``` Workaround: Run the mvn test on the command line and the tests will execute. According to the following Stackoverflow: https://stackoverflow.com/questions/57040675/java-lang-noclassdeffounderror-org-junit-platform-commons-preconditionviolation adding the following dependency to the project will fix. (I've tried with the example project and it seems to work). ``` <dependency> <groupId>org.junit.platform</groupId> <artifactId>junit-platform-commons</artifactId> <version>1.5.2</version> </dependency> ```

diff --git a/pom.xml b/pom.xml index 020c784c62fd..22dedc14a59e 100644 --- a/pom.xml +++ b/pom.xml @@ -39,7 +39,7 @@ <spring-data.version>2.0.14.RELEASE</spring-data.version> <h2.version>1.4.190</h2.version> <junit.version>4.12</junit.version> - <junit-jupiter.version>5.0.2</junit-jupiter.version> + <junit-jupiter.version>5.5.2</junit-jupiter.version> <junit-vintage.version>${junit.version}.2</junit-vintage.version> <sping-test-junit5.version>1.0.2</sping-test-junit5.version> <compiler.version>3.8.1</compiler.version> @@ -242,6 +242,12 @@ <version>${junit.version}</version> <scope>test</scope> </dependency> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-api</artifactId> + <version>${junit-jupiter.version}</version> + <scope>test</scope> + </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId>

train

train

oconnelc

train

iluwatar/java-design-patterns/1011_1017

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1011

iluwatar/java-design-patterns/1017

880b234d8fa328619e2505650849fec4c319d9fa

c308ca09e5018aecd9ee409d6fdddb0d18d3a3de

SonarCloud reports vulnerabilities

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blocker level vulnerabilities. In this task those are fixed or marked as false positives. To mark false positives, `SuppressWarnings` annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity vulnerabilities in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=VULNERABILITY) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues)

diff --git a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java index cd30afc4807c..ccbe6f2fe68c 100644 --- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java +++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java @@ -22,11 +22,12 @@ */ package com.iluwatar.aggregator.microservices; +import javax.annotation.Resource; + import org.springframework.web.bind.annotation.RequestMapping; +import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; -import javax.annotation.Resource; - /** * The aggregator aggregates calls on various micro-services, collects * data and further publishes them under a REST endpoint. @@ -47,7 +48,7 @@ public class Aggregator { * * @return a Product. */ - @RequestMapping("/product") + @RequestMapping(path = "/product", method = RequestMethod.GET) public Product getProduct() { Product product = new Product(); product.setTitle(informationClient.getProductTitle()); diff --git a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java index cbabad1e6ff6..dc4249c6eb3d 100644 --- a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java +++ b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java @@ -23,6 +23,7 @@ package com.iluwatar.api.gateway; import org.springframework.web.bind.annotation.RequestMapping; +import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; @@ -43,7 +44,7 @@ public class ApiGateway { * Retrieves product information that desktop clients need * @return Product information for clients on a desktop */ - @RequestMapping("/desktop") + @RequestMapping(path = "/desktop", method = RequestMethod.GET) public DesktopProduct getProductDesktop() { DesktopProduct desktopProduct = new DesktopProduct(); desktopProduct.setImagePath(imageClient.getImagePath()); @@ -55,7 +56,7 @@ public DesktopProduct getProductDesktop() { * Retrieves product information that mobile clients need * @return Product information for clients on a mobile device */ - @RequestMapping("/mobile") + @RequestMapping(path = "/mobile", method = RequestMethod.GET) public MobileProduct getProductMobile() { MobileProduct mobileProduct = new MobileProduct(); mobileProduct.setPrice(priceClient.getPrice()); diff --git a/naked-objects/webapp/src/main/webapp/about/index.html b/naked-objects/webapp/src/main/webapp/about/index.html index 176bfc13a3f6..e929c5b6da33 100644 --- a/naked-objects/webapp/src/main/webapp/about/index.html +++ b/naked-objects/webapp/src/main/webapp/about/index.html @@ -82,12 +82,12 @@ <p> This app has been generated using Apache Isis' - <a href="http://isis.apache.org/intro/getting-started/simple%61pp-archetype.html" target="_blank">SimpleApp</a> archetype, + <a href="http://isis.apache.org/intro/getting-started/simple%61pp-archetype.html" target="_blank" rel="noopener noreferrer">SimpleApp</a> archetype, to create a purposefully minimal application that nevertheless includes fixture data, integration tests and BDD specs. <br/> <br/> - The app itself consists of a single domain class, <a href="https://github.com/apache/isis/blob/master/example/application/simple%61pp/dom/src/main/java/dom/simple/SimpleObject.java" target="_blank"><tt>SimpleObject</tt></a>, - along with an equally simple (factory/repository) domain service, <a href="https://github.com/apache/isis/blob/master/example/application/simple%61pp/dom/src/main/java/dom/simple/SimpleObjects.java" target="_blank"><tt>SimpleObjects</tt></a>. + The app itself consists of a single domain class, <a href="https://github.com/apache/isis/blob/master/example/application/simple%61pp/dom/src/main/java/dom/simple/SimpleObject.java" target="_blank" rel="noopener noreferrer"><tt>SimpleObject</tt></a>, + along with an equally simple (factory/repository) domain service, <a href="https://github.com/apache/isis/blob/master/example/application/simple%61pp/dom/src/main/java/dom/simple/SimpleObjects.java" target="_blank" rel="noopener noreferrer"><tt>SimpleObjects</tt></a>. </p> <p>To access the app:</p> @@ -98,8 +98,8 @@ </p> <p> provides accesses to a generic UI for end-users, - Isis' <a href="http://isis.apache.org/components/viewers/wicket/about.html" target="_blank">Wicket Viewer</a>. - As its name suggests, this viewer is built on top of <a href="http://wicket.apache.org" target="_blank">Apache Wicket</a>&trade;. + Isis' <a href="http://isis.apache.org/components/viewers/wicket/about.html" target="_blank" rel="noopener noreferrer">Wicket Viewer</a>. + As its name suggests, this viewer is built on top of <a href="http://wicket.apache.org" target="_blank" rel="noopener noreferrer">Apache Wicket</a>&trade;. </p> </li> <li> @@ -118,7 +118,7 @@ <p> The default user/password is <b><i>sven/pass</i></b> (as configured in the - <a href="https://github.com/apache/isis/blob/master/example/application/simple%61pp/webapp/src/main/webapp/WEB-INF/shiro.ini" target="_blank">shiro.ini</a> file). + <a href="https://github.com/apache/isis/blob/master/example/application/simple%61pp/webapp/src/main/webapp/WEB-INF/shiro.ini" target="_blank" rel="noopener noreferrer">shiro.ini</a> file). </p> </div>

test

train

iluwatar

train

iluwatar/java-design-patterns/1016_1018

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1016

iluwatar/java-design-patterns/1018

2982db456db68f5a1e30eb7f53bea1dac054f974

0c60a95d8f0da0275db6b16f685444db96fe1837

Checkstyle should use google_checks.xml

At the moment maven-checkstyle-plugin in main pom.xml has been configured to use custom rules defined in checkstyle.xml. However there shouldn't be many modifications compared to the builtin google_checks.xml and it would be beneficial to start using this so that own rules wouldn't have to be maintained.

diff --git a/checkstyle.xml b/checkstyle.xml deleted file mode 100644 index d66281f178c6..000000000000 --- a/checkstyle.xml +++ /dev/null @@ -1,197 +0,0 @@ -<?xml version="1.0"?> -<!-- - - The MIT License - Copyright © 2014-2019 Ilkka Seppälä - - Permission is hereby granted, free of charge, to any person obtaining a copy - of this software and associated documentation files (the "Software"), to deal - in the Software without restriction, including without limitation the rights - to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - copies of the Software, and to permit persons to whom the Software is - furnished to do so, subject to the following conditions: - - The above copyright notice and this permission notice shall be included in - all copies or substantial portions of the Software. - - THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - THE SOFTWARE. - ---> -<!DOCTYPE module PUBLIC - "-//Puppy Crawl//DTD Check Configuration 1.3//EN" - "http://www.puppycrawl.com/dtds/configuration_1_3.dtd"> - -<!-- - - Source = https://github.com/checkstyle/checkstyle/tree/master/src/main/resources - - Checkstyle configurartion that checks the Google coding conventions from: - - - Google Java Style - https://google-styleguide.googlecode.com/svn-history/r130/trunk/javaguide.html - - Checkstyle is very configurable. Be sure to read the documentation at - http://checkstyle.sf.net (or in your downloaded distribution). - - Most Checks are configurable, be sure to consult the documentation. - - To completely disable a check, just comment it out or delete it from the file. - - Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov. - - --> - -<module name="Checker"> - <property name="charset" value="UTF-8"/> - - <property name="fileExtensions" value="java, xml, properties"/> - - <property name="severity" value="error"/> - - <!-- Checks for whitespace --> - <!-- See http://checkstyle.sf.net/config_whitespace.html --> - <module name="FileTabCharacter"> - <property name="eachLine" value="true"/> - </module> - - <module name="TreeWalker"> - <module name="OuterTypeFilename"/> - <module name="IllegalTokenText"> - <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/> - <property name="format" - value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/> - <property name="message" value="Avoid using corresponding octal or Unicode escape."/> - </module> - <module name="AvoidEscapedUnicodeCharacters"> - <property name="allowEscapesForControlCharacters" value="true"/> - <property name="allowByTailComment" value="true"/> - <property name="allowNonPrintableEscapes" value="true"/> - </module> - <module name="LineLength"> - <property name="max" value="120"/> - <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/> - </module> - <module name="OneTopLevelClass"/> - <module name="NoLineWrap"/> - <module name="EmptyBlock"> - <property name="option" value="TEXT"/> - <property name="tokens" - value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/> - </module> - <module name="NeedBraces"/> - <module name="LeftCurly"/> - <module name="RightCurly"/> - <module name="RightCurly"> - <property name="option" value="alone"/> - <property name="tokens" - value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO, STATIC_INIT, INSTANCE_INIT"/> - </module> - <module name="WhitespaceAround"> - <property name="allowEmptyConstructors" value="true"/> - <property name="allowEmptyMethods" value="true"/> - <property name="allowEmptyTypes" value="true"/> - <property name="allowEmptyLoops" value="true"/> - <message key="ws.notFollowed" - value="WhitespaceAround: ''{0}'' is not followed by whitespace."/> - <message key="ws.notPreceded" - value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/> - </module> - <module name="OneStatementPerLine"/> - <module name="MultipleVariableDeclarations"/> - <module name="ArrayTypeStyle"/> - <module name="MissingSwitchDefault"/> - <module name="FallThrough"/> - <module name="UpperEll"/> - <module name="ModifierOrder"/> - <module name="SeparatorWrap"> - <property name="tokens" value="DOT"/> - <property name="option" value="nl"/> - </module> - <module name="SeparatorWrap"> - <property name="tokens" value="COMMA"/> - <property name="option" value="EOL"/> - </module> - - <!-- Checks for Naming Conventions. --> - <!-- See http://checkstyle.sf.net/config_naming.html --> - <module name="ConstantName"/> - <module name="LocalFinalVariableName"/> - <module name="LocalVariableName"/> - <module name="MemberName"/> - <module name="MethodName"/> - <module name="PackageName"/> - <module name="ParameterName"/> - <module name="StaticVariableName"/> - <module name="TypeName"/> - - <module name="NoFinalizer"/> - <module name="GenericWhitespace"> - <message key="ws.followed" - value="GenericWhitespace ''{0}'' is followed by whitespace."/> - <message key="ws.preceded" - value="GenericWhitespace ''{0}'' is preceded with whitespace."/> - <message key="ws.illegalFollow" - value="GenericWhitespace ''{0}'' should followed by whitespace."/> - <message key="ws.notPreceded" - value="GenericWhitespace ''{0}'' is not preceded with whitespace."/> - </module> - <module name="Indentation"> - <property name="basicOffset" value="2"/> - <property name="braceAdjustment" value="0"/> - <property name="caseIndent" value="2"/> - <property name="throwsIndent" value="4"/> - <property name="lineWrappingIndentation" value="4"/> - <property name="arrayInitIndent" value="2"/> - </module> - <module name="AbbreviationAsWordInName"> - <property name="ignoreFinal" value="false"/> - <property name="allowedAbbreviationLength" value="1"/> - </module> - <module name="OverloadMethodsDeclarationOrder"/> - <module name="MethodParamPad"/> - <module name="OperatorWrap"> - <property name="option" value="NL"/> - <property name="tokens" - value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR "/> - </module> - <module name="AnnotationLocation"> - <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/> - </module> - <module name="AnnotationLocation"> - <property name="tokens" value="VARIABLE_DEF"/> - <property name="allowSamelineMultipleAnnotations" value="true"/> - </module> - <module name="NonEmptyAtclauseDescription"/> - <module name="JavadocTagContinuationIndentation"/> - <module name="AtclauseOrder"> - <property name="tagOrder" value="@param, @return, @throws, @deprecated"/> - <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/> - </module> - <module name="JavadocMethod"> - <property name="scope" value="public"/> - <property name="allowMissingParamTags" value="true"/> - <property name="allowMissingThrowsTags" value="true"/> - <property name="allowMissingReturnTag" value="true"/> - <property name="minLineCount" value="2"/> - <property name="allowedAnnotations" value="Override, Test, Before, After, Parameters, Given, When, BeforeClass, AfterClass, Parameterized, ParameterizedTest, BeforeAll, BeforeEach"/> - <property name="allowThrowsTagsForSubclasses" value="true"/> - </module> - <module name="JavadocType"> - <property name="scope" value="public"/> - <property name="allowUnknownTags" value="true"/> - </module> - <module name="MethodName"> - <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/> - <message key="name.invalidPattern" - value="Method name ''{0}'' must match pattern ''{1}''."/> - </module> - <module name="SingleLineJavadoc"/> - </module> - -</module> diff --git a/pom.xml b/pom.xml index 22dedc14a59e..0ef4890ca065 100644 --- a/pom.xml +++ b/pom.xml @@ -395,11 +395,10 @@ </goals> <phase>validate</phase> <configuration> - <configLocation>checkstyle.xml</configLocation> + <configLocation>google_checks.xml</configLocation> <suppressionsLocation>checkstyle-suppressions.xml</suppressionsLocation> <encoding>UTF-8</encoding> - <consoleOutput>true</consoleOutput> - <failsOnError>true</failsOnError> + <failOnViolation>true</failOnViolation> <includeTestSourceDirectory>true</includeTestSourceDirectory> </configuration> </execution>

val

train

iluwatar

train

iluwatar/java-design-patterns/1010_1023

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1010

iluwatar/java-design-patterns/1023

f671f03d13966c9c5b3b65625224912336db86dd

82f9a6c2323b412036965fc51e5ec155b6cf7741

SonarCloud reports bugs

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blocker and critical severity bugs. In this task those are fixed or marked as false positives. To mark false positives, `SuppressWarnings` annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity bugs in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=BUG) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues)

diff --git a/hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java b/hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java index bc4e963e1808..29a9d3233889 100644 --- a/hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java +++ b/hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java @@ -102,8 +102,7 @@ public static void submitTickets(LotteryService lotteryService, int numTickets) } private static PlayerDetails getRandomPlayerDetails() { - Random random = new Random(); - int idx = random.nextInt(PLAYERS.size()); + int idx = RANDOM.nextInt(PLAYERS.size()); return PLAYERS.get(idx); } } diff --git a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java index e04cce4f018a..6014da0cf1ce 100644 --- a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java +++ b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java @@ -71,8 +71,7 @@ Cell getNewCell() { } void addNewCell(Cell c) { - Random rand = new Random(); - c.candy = randomCode[rand.nextInt(randomCode.length)]; //changing candytype to new + c.candy = randomCode[RANDOM.nextInt(randomCode.length)]; //changing candytype to new this.pool.add(c); pointer++; }

test

train

iluwatar

train

iluwatar/java-design-patterns/1009_1030

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1009

iluwatar/java-design-patterns/1030

acaa6cdc62b92e874357f02239dd8f51dc155f6b

1cb1bdcb5778f911f67af70068f4d304f9094097

Redundant dependency declarations on child poms

I've noticed that there are redeclaration of dependencies (e.g: junit 5 engine/mockito) on our modules. I don't think we'll be needing those since they are already specified on the parent pom. Might be a good idea to have an issue that will do cleanups on child poms. Wdyt? @iluwatar

diff --git a/cqrs/pom.xml b/cqrs/pom.xml index b3afda05c226..feab9d1acacb 100644 --- a/cqrs/pom.xml +++ b/cqrs/pom.xml @@ -50,8 +50,8 @@ <dependency> <groupId>com.sun.xml.bind</groupId> <artifactId>jaxb-impl</artifactId> - <scope>test</scope> <version>2.1.17</version> + <scope>test</scope> </dependency> <dependency> <groupId>javax.xml.bind</groupId> diff --git a/eip-aggregator/pom.xml b/eip-aggregator/pom.xml index 3410b4504379..e4b96d0aa75d 100644 --- a/eip-aggregator/pom.xml +++ b/eip-aggregator/pom.xml @@ -43,7 +43,6 @@ <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-core</artifactId> - <version>${camel.version}</version> </dependency> <dependency> diff --git a/eip-splitter/pom.xml b/eip-splitter/pom.xml index 906a43d22a27..6aef2dc09953 100644 --- a/eip-splitter/pom.xml +++ b/eip-splitter/pom.xml @@ -43,7 +43,6 @@ <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-core</artifactId> - <version>${camel.version}</version> </dependency> <dependency> diff --git a/eip-wire-tap/pom.xml b/eip-wire-tap/pom.xml index f44bbd232979..ae896f0d0399 100644 --- a/eip-wire-tap/pom.xml +++ b/eip-wire-tap/pom.xml @@ -43,7 +43,6 @@ <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-core</artifactId> - <version>${camel.version}</version> </dependency> <dependency> diff --git a/trampoline/pom.xml b/trampoline/pom.xml index a0f25fc39b56..99ef231ef534 100644 --- a/trampoline/pom.xml +++ b/trampoline/pom.xml @@ -38,7 +38,6 @@ <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> - <version>4.12</version> <scope>test</scope> </dependency>

train

train

jjjimenez100

train

iluwatar/java-design-patterns/1037_1045

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1037

iluwatar/java-design-patterns/1045

fadad43f8b85daabc06f87fb55784a4aac9c2a54

5d47488fe9165374821d2c3d3c0bf84a421cf110

Error when building from submodule directories

When running `mvn clean install` from project's submodules, the following error message is outputted ``` Failed to execute goal com.mycila:license-maven-plugin:3.0:format (install-format) on project adapter: Resource license-plugin-header-style.xml not found in file system, classpath or URL: no protocol: license-plugin-header-style.xml ``` Building from the submodules should work as well as building from the multimodule root.

diff --git a/pom.xml b/pom.xml index b6c1b4472a88..1bcf73b8b4d5 100644 --- a/pom.xml +++ b/pom.xml @@ -406,6 +406,31 @@ </executions> </plugin> + <!-- Resolves ${projectRoot} to the project root directory. + Used by the license-maven-plugin to find the correct location of + license-plugin-header-style.xml when built from a submodule directory. --> + <plugin> + <groupId>org.commonjava.maven.plugins</groupId> + <artifactId>directory-maven-plugin</artifactId> + <version>0.3.1</version> + <executions> + <execution> + <id>directories</id> + <goals> + <goal>directory-of</goal> + </goals> + <phase>initialize</phase> + <configuration> + <property>projectRoot</property> + <project> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + </project> + </configuration> + </execution> + </executions> + </plugin> + <plugin> <groupId>com.mycila</groupId> <artifactId>license-maven-plugin</artifactId> @@ -417,7 +442,7 @@ </properties> <skipExistingHeaders>true</skipExistingHeaders> <headerDefinitions> - <headerDefinition>license-plugin-header-style.xml</headerDefinition> + <headerDefinition>${projectRoot}${file.separator}license-plugin-header-style.xml</headerDefinition> </headerDefinitions> <mapping> <java>SLASHSTAR_CUSTOM_STYLE</java>

val

train

iluwatar

train

iluwatar/java-design-patterns/1161_1214

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1161

iluwatar/java-design-patterns/1214

be1c0b81433ab4965be95f76c072c49908ca1378

751b3b945206bed390730f780070a73f5fe2d500

Aggregator Microservices

Credits link in Aggregator Microservices is responded with a blank page. The current link is http://blog.arungupta.me/microservice-design-patterns/

diff --git a/aggregator-microservices/README.md b/aggregator-microservices/README.md index 4d64178a66a5..74a411fc5cfb 100644 --- a/aggregator-microservices/README.md +++ b/aggregator-microservices/README.md @@ -27,4 +27,4 @@ Use the Aggregator Microservices pattern when you need a unified API for various ## Credits -* [Microservice Design Patterns](http://blog.arungupta.me/microservice-design-patterns/) +* [Microservice Design Patterns](http://web.archive.org/web/20190705163602/http://blog.arungupta.me/microservice-design-patterns/)

train

train

karthikmucheli

train

iluwatar/java-design-patterns/1218_1221

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1218

iluwatar/java-design-patterns/1221

751b3b945206bed390730f780070a73f5fe2d500

1c26bd741615e73579e5b70fdc84d96ca23c69e8

Arrange, Act, Assert pattern

AAA is a way to structure your unit tests so they're easier to read, maintain, and enhance. Reference: https://blog.ncrunch.net/post/arrange-act-assert-aaa-testing.aspx

diff --git a/arrange-act-assert/README.md b/arrange-act-assert/README.md new file mode 100644 index 000000000000..02b7ee8b7398 --- /dev/null +++ b/arrange-act-assert/README.md @@ -0,0 +1,30 @@ +--- +layout: pattern +title: Arrange/Act/Assert +folder: arrange-act-assert +permalink: /patterns/arrange-act-assert/ +categories: Idiom +tags: + - Testing +--- + +## Also known as +Given/When/Then + +## Intent +The Arrange/Act/Assert (AAA) is a pattern for organizing unit tests. +It breaks tests down into three clear and distinct steps: +1. Arrange: Perform the setup and initialization required for the test. +2. Act: Take action(s) required for the test. +3. Assert: Verify the outcome(s) of the test. + +## Applicability +Use Arrange/Act/Assert pattern when + +* you need to structure your unit tests so they're easier to read, maintain, and enhance. + +## Credits + +* [Arrange, Act, Assert: What is AAA Testing?](https://blog.ncrunch.net/post/arrange-act-assert-aaa-testing.aspx) +* [Bill Wake: 3A – Arrange, Act, Assert](https://xp123.com/articles/3a-arrange-act-assert/) +* [Martin Fowler: GivenWhenThen](https://martinfowler.com/bliki/GivenWhenThen.html) diff --git a/arrange-act-assert/etc/arrange-act-assert.urm.puml b/arrange-act-assert/etc/arrange-act-assert.urm.puml new file mode 100644 index 000000000000..4b22d2a4e4bb --- /dev/null +++ b/arrange-act-assert/etc/arrange-act-assert.urm.puml @@ -0,0 +1,11 @@ +@startuml +package com.iluwatar.arrangeactassert { + class Cash { + - amount : int + ~ Cash(amount : int) + ~ count() : int + ~ minus(subtrahend : int) : boolean + ~ plus(addend : int) + } +} +@enduml \ No newline at end of file diff --git a/arrange-act-assert/pom.xml b/arrange-act-assert/pom.xml new file mode 100644 index 000000000000..bb0387e7a6aa --- /dev/null +++ b/arrange-act-assert/pom.xml @@ -0,0 +1,44 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + The MIT License + Copyright © 2014-2019 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <parent> + <artifactId>java-design-patterns</artifactId> + <groupId>com.iluwatar</groupId> + <version>1.23.0-SNAPSHOT</version> + </parent> + <modelVersion>4.0.0</modelVersion> + + <artifactId>arrange-act-assert</artifactId> + <dependencies> + <dependency> + <groupId>junit</groupId> + <artifactId>junit</artifactId> + <scope>test</scope> + </dependency> + </dependencies> +</project> \ No newline at end of file diff --git a/arrange-act-assert/src/main/java/com/iluwatar/arrangeactassert/Cash.java b/arrange-act-assert/src/main/java/com/iluwatar/arrangeactassert/Cash.java new file mode 100644 index 000000000000..71269359ea58 --- /dev/null +++ b/arrange-act-assert/src/main/java/com/iluwatar/arrangeactassert/Cash.java @@ -0,0 +1,57 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.arrangeactassert; + +/** + * Arrange/Act/Assert (AAA) is a unit test pattern. In this simple example, we have a ({@link Cash}) + * object for plus, minus and counting amount. + */ +public class Cash { + + private int amount; + + Cash(int amount) { + this.amount = amount; + } + + //plus + void plus(int addend) { + amount += addend; + } + + //minus + boolean minus(int subtrahend) { + if (amount >= subtrahend) { + amount -= subtrahend; + return true; + } else { + return false; + } + } + + //count + int count() { + return amount; + } +} diff --git a/pom.xml b/pom.xml index b81cfe8d483e..97deda70313b 100644 --- a/pom.xml +++ b/pom.xml @@ -184,6 +184,7 @@ <module>combinator</module> <module>update-method</module> <module>leader-followers</module> + <module>arrange-act-assert</module> </modules> <repositories>

diff --git a/arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java b/arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java new file mode 100644 index 000000000000..d7841843db37 --- /dev/null +++ b/arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java @@ -0,0 +1,99 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.arrangeactassert; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +import org.junit.Test; + +/** + * Arrange/Act/Assert (AAA) is a pattern for organizing unit tests. It is a way to structure your + * tests so they're easier to read, maintain and enhance. + * + * <p>It breaks tests down into three clear and distinct steps: + * <p>1. Arrange: Perform the setup and initialization required for the test. + * <p>2. Act: Take action(s) required for the test. + * <p>3. Assert: Verify the outcome(s) of the test. + * + * <p>This pattern has several significant benefits. It creates a clear separation between a test's + * setup, operations, and results. This structure makes the code easier to read and understand. If + * you place the steps in order and format your code to separate them, you can scan a test and + * quickly comprehend what it does. + * + * <p>It also enforces a certain degree of discipline when you write your tests. You have to think + * clearly about the three steps your test will perform. But it makes tests more natural to write at + * the same time since you already have an outline. + * + * <p>In ({@link CashAAATest}) we have four test methods. Each of them has only one reason to + * change and one reason to fail. In a large and complicated code base, tests that honor the single + * responsibility principle are much easier to troubleshoot. + */ +public class CashAAATest { + + @Test + public void testPlus() { + //Arrange + var cash = new Cash(3); + //Act + cash.plus(4); + //Assert + assertEquals(cash.count(), 7); + } + + @Test + public void testMinus() { + //Arrange + var cash = new Cash(8); + //Act + var result = cash.minus(5); + //Assert + assertTrue(result); + assertEquals(cash.count(), 3); + } + + @Test + public void testInsufficientMinus() { + //Arrange + var cash = new Cash(1); + //Act + var result = cash.minus(6); + //Assert + assertFalse(result); + assertEquals(cash.count(), 1); + } + + @Test + public void testUpdate() { + //Arrange + var cash = new Cash(5); + //Act + cash.plus(6); + var result = cash.minus(3); + //Assert + assertTrue(result); + assertEquals(cash.count(), 8); + } +} diff --git a/arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java b/arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java new file mode 100644 index 000000000000..3f8c33d5ea95 --- /dev/null +++ b/arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java @@ -0,0 +1,59 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.arrangeactassert; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +import org.junit.Test; + +/** + * ({@link CashAAATest}) is an anti-example of AAA pattern. This test is functionally correct, but + * with the addition of new feature, it needs refactoring. There are an awful lot of steps in that + * test method, but it verifies the class' important behavior in just eleven lines. It violates the + * single responsibility principle. If this test method failed after a small code change, it might + * take some digging to discover why. + */ +public class CashAntiAAATest { + + @Test + public void testCash() { + //initialize + var cash = new Cash(3); + //test plus + cash.plus(4); + assertEquals(cash.count(), 7); + //test minus + cash = new Cash(8); + assertTrue(cash.minus(5)); + assertEquals(cash.count(), 3); + assertFalse(cash.minus(6)); + assertEquals(cash.count(), 3); + //test update + cash.plus(5); + assertTrue(cash.minus(5)); + assertEquals(cash.count(), 3); + } +}

train

train

iluwatar

train

iluwatar/java-design-patterns/1339_1342

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1339

iluwatar/java-design-patterns/1342

4b88214baef78c362806311d88f96bebb0cd4d21

54c0b1725c522666e7dbdcb973719cefb7a9daed

Service Layer logging broken

At the moment the Service Layer pattern example does not produce log output at all.

diff --git a/service-layer/src/main/resources/logback.xml b/service-layer/src/main/resources/logback.xml index 47fe422366d8..e6678aff2e8f 100644 --- a/service-layer/src/main/resources/logback.xml +++ b/service-layer/src/main/resources/logback.xml @@ -43,6 +43,7 @@ <logger name="com.iluwatar" additivity="false"> <level value="DEBUG"/> <appender-ref ref="FILE"/> + <appender-ref ref="STDOUT"/> </logger> <logger name="org.hibernate" additivity="false">

val

train

iluwatar

train

iluwatar/java-design-patterns/1324_1472

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1324

iluwatar/java-design-patterns/1472

9ff5b9e7c09277cc51c3b26224608c699b457156

97285d37244fd0d524b6e9d9aa8dae48f1fa0cc3

Inheritence in Command pattern

I see that the `Command` is a class instead of `interface` and all the target actions extends this class. Typically `Command` should be interface and the targets should implement the interface. So should we rewrite the command pattern to implement interface rather than using inheritance?

diff --git a/command/README.md b/command/README.md index fc0a11d9ffe8..b763cf4dd1c5 100644 --- a/command/README.md +++ b/command/README.md @@ -75,19 +75,18 @@ public class Wizard { Next we present the spell hierarchy. ```java -public abstract class Command { +public interface Command { - public abstract void execute(Target target); + void execute(Target target); - public abstract void undo(); + void undo(); - public abstract void redo(); + void redo(); - @Override - public abstract String toString(); + String toString(); } -public class InvisibilitySpell extends Command { +public class InvisibilitySpell implements Command { private Target target; @@ -117,7 +116,7 @@ public class InvisibilitySpell extends Command { } } -public class ShrinkSpell extends Command { +public class ShrinkSpell implements Command { private Size oldSize; private Target target; diff --git a/command/etc/command.urm.puml b/command/etc/command.urm.puml index a8b773418ee3..c9c172226fa3 100644 --- a/command/etc/command.urm.puml +++ b/command/etc/command.urm.puml @@ -4,7 +4,7 @@ package com.iluwatar.command { + App() + main(args : String[]) {static} } - abstract class Command { + interface Command { + Command() + execute(Target) {abstract} + redo() {abstract} @@ -77,7 +77,7 @@ ShrinkSpell --> "-oldSize" Size InvisibilitySpell --> "-target" Target ShrinkSpell --> "-target" Target Target --> "-visibility" Visibility -Goblin --|> Target -InvisibilitySpell --|> Command -ShrinkSpell --|> Command -@enduml \ No newline at end of file +Goblin --|> Target +InvisibilitySpell ..|> Command +ShrinkSpell ..|> Command +@enduml diff --git a/command/src/main/java/com/iluwatar/command/Command.java b/command/src/main/java/com/iluwatar/command/Command.java index 85deff74efd8..83010f1604d0 100644 --- a/command/src/main/java/com/iluwatar/command/Command.java +++ b/command/src/main/java/com/iluwatar/command/Command.java @@ -26,15 +26,12 @@ /** * Interface for Commands. */ -public abstract class Command { +public interface Command { + void execute(Target target); - public abstract void execute(Target target); + void undo(); - public abstract void undo(); - - public abstract void redo(); - - @Override - public abstract String toString(); + void redo(); + String toString(); } diff --git a/command/src/main/java/com/iluwatar/command/InvisibilitySpell.java b/command/src/main/java/com/iluwatar/command/InvisibilitySpell.java index 3e0f7bbf4fef..33e053cc2e3b 100644 --- a/command/src/main/java/com/iluwatar/command/InvisibilitySpell.java +++ b/command/src/main/java/com/iluwatar/command/InvisibilitySpell.java @@ -26,7 +26,7 @@ /** * InvisibilitySpell is a concrete command. */ -public class InvisibilitySpell extends Command { +public class InvisibilitySpell implements Command { private Target target; diff --git a/command/src/main/java/com/iluwatar/command/ShrinkSpell.java b/command/src/main/java/com/iluwatar/command/ShrinkSpell.java index 87497bb7bed8..3f21fc7c1fc7 100644 --- a/command/src/main/java/com/iluwatar/command/ShrinkSpell.java +++ b/command/src/main/java/com/iluwatar/command/ShrinkSpell.java @@ -26,7 +26,7 @@ /** * ShrinkSpell is a concrete command. */ -public class ShrinkSpell extends Command { +public class ShrinkSpell implements Command { private Size oldSize; private Target target;

train

train

ravening

train

iluwatar/java-design-patterns/1338_1485

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1338

iluwatar/java-design-patterns/1485

1e90d0d645e637cb716b1f3f40d259345fd8bf9d

2c6f1832b0d328240e270dc0051d4c9e1af682ee

Logging in API Gateway

At the moment api-gateway pattern does not use a proper logger as in other examples. In this issue we fix that.

diff --git a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java index 52dd065ffc35..6fea815fc86d 100644 --- a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java +++ b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java @@ -23,11 +23,16 @@ package com.iluwatar.api.gateway; +import static org.slf4j.LoggerFactory.getLogger; + import java.io.IOException; import java.net.URI; import java.net.http.HttpClient; import java.net.http.HttpRequest; +import java.net.http.HttpResponse; import java.net.http.HttpResponse.BodyHandlers; + +import org.slf4j.Logger; import org.springframework.stereotype.Component; /** @@ -35,6 +40,8 @@ */ @Component public class ImageClientImpl implements ImageClient { + private static final Logger LOGGER = getLogger(ImageClientImpl.class); + /** * Makes a simple HTTP Get request to the Image microservice. * @@ -49,12 +56,26 @@ public String getImagePath() { .build(); try { + LOGGER.info("Sending request to fetch image path"); var httpResponse = httpClient.send(httpGet, BodyHandlers.ofString()); + logResponse(httpResponse); return httpResponse.body(); } catch (IOException | InterruptedException e) { - e.printStackTrace(); + LOGGER.error("Failure occurred while getting image path", e); } return null; } + + private void logResponse(HttpResponse<String> httpResponse) { + if (isSuccessResponse(httpResponse.statusCode())) { + LOGGER.info("Image path received successfully"); + } else { + LOGGER.warn("Image path request failed"); + } + } + + private boolean isSuccessResponse(int responseCode) { + return responseCode >= 200 && responseCode <= 299; + } } diff --git a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java index 0dc44a51bced..f773d0d54c7a 100644 --- a/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java +++ b/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java @@ -23,18 +23,26 @@ package com.iluwatar.api.gateway; +import static org.slf4j.LoggerFactory.getLogger; + import java.io.IOException; import java.net.URI; import java.net.http.HttpClient; import java.net.http.HttpRequest; +import java.net.http.HttpResponse; import java.net.http.HttpResponse.BodyHandlers; + +import org.slf4j.Logger; import org.springframework.stereotype.Component; + /** * An adapter to communicate with the Price microservice. */ @Component public class PriceClientImpl implements PriceClient { + private static final Logger LOGGER = getLogger(PriceClientImpl.class); + /** * Makes a simple HTTP Get request to the Price microservice. * @@ -49,12 +57,26 @@ public String getPrice() { .build(); try { + LOGGER.info("Sending request to fetch price info"); var httpResponse = httpClient.send(httpGet, BodyHandlers.ofString()); + logResponse(httpResponse); return httpResponse.body(); } catch (IOException | InterruptedException e) { - e.printStackTrace(); + LOGGER.error("Failure occurred while getting price info", e); } return null; } + + private void logResponse(HttpResponse<String> httpResponse) { + if (isSuccessResponse(httpResponse.statusCode())) { + LOGGER.info("Price info received successfully"); + } else { + LOGGER.warn("Price info request failed"); + } + } + + private boolean isSuccessResponse(int responseCode) { + return responseCode >= 200 && responseCode <= 299; + } } diff --git a/api-gateway/image-microservice/src/main/java/com/iluwatar/image/microservice/ImageController.java b/api-gateway/image-microservice/src/main/java/com/iluwatar/image/microservice/ImageController.java index b1f6dd3f7eb6..a96ef4f413a7 100644 --- a/api-gateway/image-microservice/src/main/java/com/iluwatar/image/microservice/ImageController.java +++ b/api-gateway/image-microservice/src/main/java/com/iluwatar/image/microservice/ImageController.java @@ -23,15 +23,20 @@ package com.iluwatar.image.microservice; +import static org.slf4j.LoggerFactory.getLogger; + +import org.slf4j.Logger; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; + /** * Exposes the Image microservice's endpoints. */ @RestController public class ImageController { + private static final Logger LOGGER = getLogger(ImageController.class); /** * An endpoint for a user to retrieve an image path. @@ -40,6 +45,7 @@ public class ImageController { */ @RequestMapping(value = "/image-path", method = RequestMethod.GET) public String getImagePath() { + LOGGER.info("Successfully found image path"); return "/product-image.png"; } } diff --git a/api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceController.java b/api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceController.java index cf2f5eb4f83b..dbcd59952945 100644 --- a/api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceController.java +++ b/api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceController.java @@ -23,15 +23,20 @@ package com.iluwatar.price.microservice; +import static org.slf4j.LoggerFactory.getLogger; + +import org.slf4j.Logger; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; + /** * Exposes the Price microservice's endpoints. */ @RestController public class PriceController { + private static final Logger LOGGER = getLogger(PriceController.class); /** * An endpoint for a user to retrieve a product's price. @@ -40,6 +45,7 @@ public class PriceController { */ @RequestMapping(value = "/price", method = RequestMethod.GET) public String getPrice() { + LOGGER.info("Successfully found price info"); return "20"; } }

train

train

iluwatar

train

iluwatar/java-design-patterns/1500_1505

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1500

iluwatar/java-design-patterns/1505

6d83ceba285fb2a62119f6169d8041ec05c196c4

15d795bf8a92c65cbb42a5889a351e317729c031

Use the same JUnit version everywhere

At the moment there are some modules that are still using JUnit 4. Most of the codebase uses JUnit 5, but even with that there are different versions. For example `unit-of-work` and `partial-response` declare their own versions. In this ticket let's try to apply the same version of JUnit 5 everywhere upgrading from JUnit 4 where needed. ## This issue has been partially addressed using #1542 and #1668 Tests from two modules [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) and [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) are not being executed. Respective issues have been opened for resolving the tests in favour of these two modules. - [x] #1667 against [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) - [ ] #1669 against [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) Resolving these two issues should close this [current issue](https://github.com/iluwatar/java-design-patterns/issues/1500)

diff --git a/pom.xml b/pom.xml index 1275ce115c83..3b7ad35686b6 100644 --- a/pom.xml +++ b/pom.xml @@ -52,7 +52,7 @@ <jaxb-api.version>2.3.1</jaxb-api.version> <jaxb-impl.version>2.3.2</jaxb-impl.version> <annotation-api.version>1.3.2</annotation-api.version> - <system-rules.version>1.19.0</system-rules.version> + <system-lambda.version>1.1.0</system-lambda.version> <urm.version>2.0.0</urm.version> <mockito-junit-jupiter.version>3.5.0</mockito-junit-jupiter.version> <!-- SonarCloud --> @@ -338,8 +338,8 @@ </dependency> <dependency> <groupId>com.github.stefanbirkner</groupId> - <artifactId>system-rules</artifactId> - <version>${system-rules.version}</version> + <artifactId>system-lambda</artifactId> + <version>${system-lambda.version}</version> <scope>test</scope> </dependency> </dependencies> diff --git a/subclass-sandbox/pom.xml b/subclass-sandbox/pom.xml index ac718291e2a4..a912ada3fdeb 100644 --- a/subclass-sandbox/pom.xml +++ b/subclass-sandbox/pom.xml @@ -42,7 +42,7 @@ </dependency> <dependency> <groupId>com.github.stefanbirkner</groupId> - <artifactId>system-rules</artifactId> + <artifactId>system-lambda</artifactId> </dependency> <dependency> <groupId>org.junit.jupiter</groupId>

diff --git a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java index 97e2ac67d16f..3b379946c6f0 100644 --- a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java +++ b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java @@ -23,55 +23,48 @@ package com.iluwatar.subclasssandbox; +import com.github.stefanbirkner.systemlambda.Statement; import org.junit.Assert; -import org.junit.Rule; import org.junit.Test; -import org.junit.contrib.java.lang.system.SystemOutRule; + +import static com.github.stefanbirkner.systemlambda.SystemLambda.tapSystemOutNormalized; /** * GroundDive unit tests. */ public class GroundDiveTest { - @Rule - public SystemOutRule log = new SystemOutRule().enableLog(); - @Test - public void testMove() { - log.clearLog(); + public void testMove() throws Exception { var groundDive = new GroundDive(); groundDive.move(1.0, 1.0, 1.0); - var outputLog = getLogContent(log.getLog()); + var outputLog = getLogContent(() -> groundDive.move(1.0, 1.0, 1.0)); var expectedLog = "Move to ( 1.0, 1.0, 1.0 )"; Assert.assertEquals(outputLog, expectedLog); } @Test - public void testPlaySound() { - log.clearLog(); + public void testPlaySound() throws Exception { var groundDive = new GroundDive(); - groundDive.playSound("SOUND_NAME", 1); - var outputLog = getLogContent(log.getLog()); + var outputLog = getLogContent(() -> groundDive.playSound("SOUND_NAME", 1)); var expectedLog = "Play SOUND_NAME with volumn 1"; Assert.assertEquals(outputLog, expectedLog); } @Test - public void testSpawnParticles() { - log.clearLog(); + public void testSpawnParticles() throws Exception { var groundDive = new GroundDive(); - groundDive.spawnParticles("PARTICLE_TYPE", 100); - final var outputLog = getLogContent(log.getLog()); + final var outputLog = getLogContent( + () -> groundDive.spawnParticles("PARTICLE_TYPE", 100)); final var expectedLog = "Spawn 100 particle with type PARTICLE_TYPE"; Assert.assertEquals(outputLog, expectedLog); } @Test - public void testActivate() { - log.clearLog(); + public void testActivate() throws Exception { var groundDive = new GroundDive(); - groundDive.activate(); - var logs = log.getLog().split("\n"); + var logs = tapSystemOutNormalized(groundDive::activate) + .split("\n"); final var expectedSize = 3; final var log1 = logs[0].split("-")[1].trim() + " -" + logs[0].split("-")[2].trim(); final var expectedLog1 = "Move to ( 0.0, 0.0, -20.0 )"; @@ -85,6 +78,11 @@ public void testActivate() { Assert.assertEquals(log3, expectedLog3); } + private String getLogContent(Statement statement) throws Exception { + var log = tapSystemOutNormalized(statement); + return getLogContent(log); + } + private String getLogContent(String log) { return log.split("-")[1].trim(); } diff --git a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java index e192737f6320..d285e6c7ddb2 100644 --- a/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java +++ b/subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java @@ -23,55 +23,47 @@ package com.iluwatar.subclasssandbox; +import com.github.stefanbirkner.systemlambda.Statement; import org.junit.Assert; -import org.junit.Rule; import org.junit.Test; -import org.junit.contrib.java.lang.system.SystemOutRule; + +import static com.github.stefanbirkner.systemlambda.SystemLambda.tapSystemOutNormalized; /** * SkyLaunch unit tests. */ public class SkyLaunchTest { - @Rule - public SystemOutRule log = new SystemOutRule().enableLog(); - @Test - public void testMove() { - log.clearLog(); + public void testMove() throws Exception { var skyLaunch = new SkyLaunch(); - skyLaunch.move(1.0, 1.0, 1.0); - var outputLog = getLogContent(log.getLog()); + var outputLog = getLogContent(() -> skyLaunch.move(1.0, 1.0, 1.0)); var expectedLog = "Move to ( 1.0, 1.0, 1.0 )"; Assert.assertEquals(outputLog, expectedLog); } @Test - public void testPlaySound() { - log.clearLog(); + public void testPlaySound() throws Exception { var skyLaunch = new SkyLaunch(); - skyLaunch.playSound("SOUND_NAME", 1); - var outputLog = getLogContent(log.getLog()); + var outputLog = getLogContent(() -> skyLaunch.playSound("SOUND_NAME", 1)); var expectedLog = "Play SOUND_NAME with volumn 1"; Assert.assertEquals(outputLog, expectedLog); } @Test - public void testSpawnParticles() { - log.clearLog(); + public void testSpawnParticles() throws Exception { var skyLaunch = new SkyLaunch(); - skyLaunch.spawnParticles("PARTICLE_TYPE", 100); - var outputLog = getLogContent(log.getLog()); + var outputLog = getLogContent( + () -> skyLaunch.spawnParticles("PARTICLE_TYPE", 100)); var expectedLog = "Spawn 100 particle with type PARTICLE_TYPE"; Assert.assertEquals(outputLog, expectedLog); } @Test - public void testActivate() { - log.clearLog(); + public void testActivate() throws Exception { var skyLaunch = new SkyLaunch(); - skyLaunch.activate(); - var logs = log.getLog().split("\n"); + var logs = tapSystemOutNormalized(skyLaunch::activate) + .split("\n"); final var expectedSize = 3; final var log1 = getLogContent(logs[0]); final var expectedLog1 = "Move to ( 0.0, 0.0, 20.0 )"; @@ -85,6 +77,11 @@ public void testActivate() { Assert.assertEquals(log3, expectedLog3); } + private String getLogContent(Statement statement) throws Exception { + var log = tapSystemOutNormalized(statement); + return getLogContent(log); + } + private String getLogContent(String log) { return log.split("-")[1].trim(); }

train

train

iluwatar

train

iluwatar/java-design-patterns/1486_1507

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1486

iluwatar/java-design-patterns/1507

9dd46d7b4a4329d07956b263dd627272e25db707

9b464e0be1a54f26bd50508d619f294d2147fa8d

Upgrade mockito

The current version declared in the main `pom.xml` is very old: ``` <mockito.version>1.10.19</mockito.version> ``` Let's try to upgrade it to a newer version in this task.

diff --git a/pom.xml b/pom.xml index 56b95520435e..6d779700f9f5 100644 --- a/pom.xml +++ b/pom.xml @@ -39,7 +39,7 @@ <commons-dbcp.version>1.4</commons-dbcp.version> <camel.version>2.24.0</camel.version> <guava.version>19.0</guava.version> - <mockito.version>1.10.19</mockito.version> + <mockito.version>3.5.6</mockito.version> <htmlunit.version>2.22</htmlunit.version> <guice.version>4.0</guice.version> <mongo-java-driver.version>3.12.1</mongo-java-driver.version> @@ -206,6 +206,18 @@ <dependencyManagement> <dependencies> + <dependency> + <groupId>net.bytebuddy</groupId> + <artifactId>byte-buddy</artifactId> + <version>1.9.7</version> + <scope>test</scope> + </dependency> + <dependency> + <groupId>net.bytebuddy</groupId> + <artifactId>byte-buddy-agent</artifactId> + <version>1.9.7</version> + <scope>test</scope> + </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId>

test

train

iluwatar

train

iluwatar/java-design-patterns/1313_1522

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1313

iluwatar/java-design-patterns/1522

ef326ee77e03077714f38df36f92ffa58ebaffa9

ebc0e8b3cd79ce644c927ad0a64dd0539d6da4e3

Separated Interface pattern

https://www.youtube.com/watch?v=d3k-hOA7k2Y

diff --git a/pom.xml b/pom.xml index da3084ab2c51..1026685881db 100644 --- a/pom.xml +++ b/pom.xml @@ -196,6 +196,7 @@ <module>transaction-script</module> <module>filterer</module> <module>factory</module> + <module>separated-interface</module> </modules> <repositories> diff --git a/separated-interface/README.md b/separated-interface/README.md new file mode 100644 index 000000000000..ca7a12e44d95 --- /dev/null +++ b/separated-interface/README.md @@ -0,0 +1,119 @@ +--- +layout: pattern +title: Separated Interface +folder: separated-interface +permalink: /patterns/separated-interface/ +categories: Structural +tags: + - Decoupling +--- + + +## Intent +Separate the interface definition and implementation in different packages. This allows the client to be completely unaware of the implementation. + +## Explanation + +Real world example + +> An Invoice generator may be created with ability to use different Tax calculators that may be added in the invoice depending upon type of purchase, region etc. + +In plain words + +> Separated interface pattern encourages to keep the implementations of an interface decoupled from the client and its definition, so the client is not dependent on the implementation. + +A client code may abstract some specific functionality to an interface, and define the definition of the interface as an SPI ([Service Programming Interface](https://en.wikipedia.org/wiki/Service_provider_interface) is an API intended and open to be implemented or extended by a third party). Another package may implement this interface definition with a concrete logic, which will be injected into the client code at runtime (with a third class, injecting the implementation in the client) or at compile time (using Plugin pattern with some configurable file). + +**Programmatic Example** + +**Client** An Invoice generator class accepts the cost of the product and calculates the total amount payable inclusive of tax + +```java +public class InvoiceGenerator { + + private final TaxCalculator taxCalculator; + + private final double amount; + + public InvoiceGenerator(double amount, TaxCalculator taxCalculator) { + this.amount = amount; + this.taxCalculator = taxCalculator; + } + + public double getAmountWithTax() { + return amount + taxCalculator.calculate(amount); + } + +} +``` +The tax calculation logic is delegated to the ```TaxCalculator``` interface + +```java + +public interface TaxCalculator { + + double calculate(double amount); + +} + +``` + +**Implementation package** +In another package (which the client is completely unaware of) there exist multiple implementations of the ```TaxCalculator``` interface +```ForeignTaxCalculator``` which levies 60% tax for international products. +```java +public class ForeignTaxCalculator implements TaxCalculator { + + public static final double TAX_PERCENTAGE = 60; + + @Override + public double calculate(double amount) { + return amount * TAX_PERCENTAGE / 100.0; + } + +} +``` + +```DomesticTaxCalculator``` which levies 20% tax for international products. +```java +public class DomesticTaxCalculator implements TaxCalculator { + + public static final double TAX_PERCENTAGE = 20; + + @Override + public double calculate(double amount) { + return amount * TAX_PERCENTAGE / 100.0; + } + +} +``` + +These both implementations are instantiated and injected in the client class by the ```App.java``` class + +```java + var internationalProductInvoice = new InvoiceGenerator(PRODUCT_COST, new ForeignTaxCalculator()); + + LOGGER.info("Foreign Tax applied: {}", "" + internationalProductInvoice.getAmountWithTax()); + + var domesticProductInvoice = new InvoiceGenerator(PRODUCT_COST, new DomesticTaxCalculator()); + + LOGGER.info("Domestic Tax applied: {}", "" + domesticProductInvoice.getAmountWithTax()); +``` + +## Class diagram + + +## Applicability +Use the Separated interface pattern when + +* You are developing a framework package, and your framework needs to call some application code through interfaces. +* You have separate packages implementing the functionalities which may be plugged in your client code at runtime or compile-time. +* Your code resides in a layer that is not allowed to call the interface implementation layer by rule. For example, a domain layer needs to call a data mapper. + +## Tutorial + +* [Separated Interface Tutorial](https://www.youtube.com/watch?v=d3k-hOA7k2Y) + +## Credits + +* [Martin Fowler](https://www.martinfowler.com/eaaCatalog/separatedInterface.html) diff --git a/separated-interface/etc/separated-interface.urm.puml b/separated-interface/etc/separated-interface.urm.puml new file mode 100644 index 000000000000..eab2ad60c98e --- /dev/null +++ b/separated-interface/etc/separated-interface.urm.puml @@ -0,0 +1,36 @@ +@startuml +package com.iluwatar.separatedinterface { + class App { + - LOGGER : Logger {static} + + PRODUCT_COST : double {static} + + App() + + main(args : String[]) {static} + } +} +package com.iluwatar.separatedinterface.taxes { + class DomesticTaxCalculator { + + TAX_PERCENTAGE : double {static} + + DomesticTaxCalculator() + + calculate(amount : double) : double + } + class ForeignTaxCalculator { + + TAX_PERCENTAGE : double {static} + + ForeignTaxCalculator() + + calculate(amount : double) : double + } +} +package com.iluwatar.separatedinterface.invoice { + class InvoiceGenerator { + - amount : double + - taxCalculator : TaxCalculator + + InvoiceGenerator(amount : double, taxCalculator : TaxCalculator) + + getAmountWithTax() : double + } + interface TaxCalculator { + + calculate(double) : double {abstract} + } +} +InvoiceGenerator --> "-taxCalculator" TaxCalculator +DomesticTaxCalculator ..|> TaxCalculator +ForeignTaxCalculator ..|> TaxCalculator +@enduml \ No newline at end of file diff --git a/separated-interface/pom.xml b/separated-interface/pom.xml new file mode 100644 index 000000000000..da7584a93b6e --- /dev/null +++ b/separated-interface/pom.xml @@ -0,0 +1,71 @@ +<?xml version="1.0"?> +<!-- + + The MIT License + Copyright © 2014-2019 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.24.0-SNAPSHOT</version> + </parent> + <artifactId>separated-interface</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-params</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.mockito</groupId> + <artifactId>mockito-core</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.separatedinterface.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> diff --git a/separated-interface/src/main/java/com/iluwatar/separatedinterface/App.java b/separated-interface/src/main/java/com/iluwatar/separatedinterface/App.java new file mode 100644 index 000000000000..1951e738b77d --- /dev/null +++ b/separated-interface/src/main/java/com/iluwatar/separatedinterface/App.java @@ -0,0 +1,62 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface; + +import com.iluwatar.separatedinterface.invoice.InvoiceGenerator; +import com.iluwatar.separatedinterface.taxes.DomesticTaxCalculator; +import com.iluwatar.separatedinterface.taxes.ForeignTaxCalculator; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * <p>The Separated Interface pattern encourages to separate the interface definition and + * implementation in different packages. This allows the client to be completely unaware of the + * implementation.</p> + * + * <p>In this class the {@link InvoiceGenerator} class is injected with different instances of + * {@link com.iluwatar.separatedinterface.invoice.TaxCalculator} implementations located in separate + * packages, to receive different responses for both of the implementations.</p> + */ +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + public static final double PRODUCT_COST = 50.0; + + /** + * Program entry point. + * + * @param args command line args + */ + public static void main(String[] args) { + //Create the invoice generator with product cost as 50 and foreign product tax + var internationalProductInvoice = new InvoiceGenerator(PRODUCT_COST, + new ForeignTaxCalculator()); + LOGGER.info("Foreign Tax applied: {}", "" + internationalProductInvoice.getAmountWithTax()); + + //Create the invoice generator with product cost as 50 and domestic product tax + var domesticProductInvoice = new InvoiceGenerator(PRODUCT_COST, new DomesticTaxCalculator()); + LOGGER.info("Domestic Tax applied: {}", "" + domesticProductInvoice.getAmountWithTax()); + } +} diff --git a/separated-interface/src/main/java/com/iluwatar/separatedinterface/invoice/InvoiceGenerator.java b/separated-interface/src/main/java/com/iluwatar/separatedinterface/invoice/InvoiceGenerator.java new file mode 100644 index 000000000000..c17ed5ac55e3 --- /dev/null +++ b/separated-interface/src/main/java/com/iluwatar/separatedinterface/invoice/InvoiceGenerator.java @@ -0,0 +1,51 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.invoice; + +/** + * InvoiceGenerator class generates an invoice, accepting the product cost and calculating the total + * price payable inclusive tax (calculated by {@link TaxCalculator}). + */ +public class InvoiceGenerator { + + /** + * The TaxCalculator interface to calculate the payable tax. + */ + private final TaxCalculator taxCalculator; + + /** + * The base product amount without tax. + */ + private final double amount; + + public InvoiceGenerator(double amount, TaxCalculator taxCalculator) { + this.amount = amount; + this.taxCalculator = taxCalculator; + } + + public double getAmountWithTax() { + return amount + taxCalculator.calculate(amount); + } + +} \ No newline at end of file diff --git a/separated-interface/src/main/java/com/iluwatar/separatedinterface/invoice/TaxCalculator.java b/separated-interface/src/main/java/com/iluwatar/separatedinterface/invoice/TaxCalculator.java new file mode 100644 index 000000000000..aa4b81a84995 --- /dev/null +++ b/separated-interface/src/main/java/com/iluwatar/separatedinterface/invoice/TaxCalculator.java @@ -0,0 +1,30 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.invoice; + +public interface TaxCalculator { + + double calculate(double amount); + +} diff --git a/separated-interface/src/main/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculator.java b/separated-interface/src/main/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculator.java new file mode 100644 index 000000000000..788afb90ab85 --- /dev/null +++ b/separated-interface/src/main/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculator.java @@ -0,0 +1,40 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.taxes; + +import com.iluwatar.separatedinterface.invoice.TaxCalculator; + +/** + * TaxCalculator for Domestic goods with 20% tax. + */ +public class DomesticTaxCalculator implements TaxCalculator { + + public static final double TAX_PERCENTAGE = 20; + + @Override + public double calculate(double amount) { + return amount * TAX_PERCENTAGE / 100.0; + } + +} diff --git a/separated-interface/src/main/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculator.java b/separated-interface/src/main/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculator.java new file mode 100644 index 000000000000..c2b12e2f5637 --- /dev/null +++ b/separated-interface/src/main/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculator.java @@ -0,0 +1,40 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.taxes; + +import com.iluwatar.separatedinterface.invoice.TaxCalculator; + +/** + * TaxCalculator for foreign goods with 60% tax. + */ +public class ForeignTaxCalculator implements TaxCalculator { + + public static final double TAX_PERCENTAGE = 60; + + @Override + public double calculate(double amount) { + return amount * TAX_PERCENTAGE / 100.0; + } + +}

diff --git a/separated-interface/src/test/java/com/iluwatar/separatedinterface/AppTest.java b/separated-interface/src/test/java/com/iluwatar/separatedinterface/AppTest.java new file mode 100644 index 000000000000..4114f9bb73d0 --- /dev/null +++ b/separated-interface/src/test/java/com/iluwatar/separatedinterface/AppTest.java @@ -0,0 +1,41 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface; + +import org.junit.jupiter.api.Test; + +import com.iluwatar.separatedinterface.App; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +/** + * Application test. + */ +class AppTest { + + @Test + void shouldExecuteWithoutException() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} diff --git a/separated-interface/src/test/java/com/iluwatar/separatedinterface/invoice/InvoiceGeneratorTest.java b/separated-interface/src/test/java/com/iluwatar/separatedinterface/invoice/InvoiceGeneratorTest.java new file mode 100644 index 000000000000..ac75d3b70c69 --- /dev/null +++ b/separated-interface/src/test/java/com/iluwatar/separatedinterface/invoice/InvoiceGeneratorTest.java @@ -0,0 +1,48 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.invoice; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.Test; + +import static org.mockito.Mockito.*; + +public class InvoiceGeneratorTest { + + private InvoiceGenerator target; + + @Test + public void testGenerateTax() { + var productCost = 50.0; + var tax = 10.0; + TaxCalculator taxCalculatorMock = mock(TaxCalculator.class); + doReturn(tax).when(taxCalculatorMock).calculate(productCost); + + target = new InvoiceGenerator(productCost, taxCalculatorMock); + + Assertions.assertEquals(target.getAmountWithTax(), productCost + tax); + verify(taxCalculatorMock, times(1)).calculate(productCost); + } + +} diff --git a/separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculatorTest.java b/separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculatorTest.java new file mode 100644 index 000000000000..dac3ec2d6a28 --- /dev/null +++ b/separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculatorTest.java @@ -0,0 +1,41 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.taxes; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.Test; + +public class DomesticTaxCalculatorTest { + + private DomesticTaxCalculator target; + + @Test + public void testTaxCalculation(){ + target = new DomesticTaxCalculator(); + + var tax=target.calculate(100.0); + Assertions.assertEquals(tax,20.0); + } + +} diff --git a/separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculatorTest.java b/separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculatorTest.java new file mode 100644 index 000000000000..22526b6dfc13 --- /dev/null +++ b/separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculatorTest.java @@ -0,0 +1,41 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.separatedinterface.taxes; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.Test; + +public class ForeignTaxCalculatorTest { + + private ForeignTaxCalculator target; + + @Test + public void testTaxCalculation(){ + target = new ForeignTaxCalculator(); + + var tax=target.calculate(100.0); + Assertions.assertEquals(tax,60.0); + } + +}

train

train

iluwatar

train

iluwatar/java-design-patterns/1500_1529

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1500

iluwatar/java-design-patterns/1529

a125879d15e82af50b757baa9f7d81efbd1c3235

f0067828058d87352bcc7a072a53837b47f235b8

Use the same JUnit version everywhere

At the moment there are some modules that are still using JUnit 4. Most of the codebase uses JUnit 5, but even with that there are different versions. For example `unit-of-work` and `partial-response` declare their own versions. In this ticket let's try to apply the same version of JUnit 5 everywhere upgrading from JUnit 4 where needed. ## This issue has been partially addressed using #1542 and #1668 Tests from two modules [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) and [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) are not being executed. Respective issues have been opened for resolving the tests in favour of these two modules. - [x] #1667 against [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) - [ ] #1669 against [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) Resolving these two issues should close this [current issue](https://github.com/iluwatar/java-design-patterns/issues/1500)

diff --git a/trampoline/pom.xml b/trampoline/pom.xml index fff117bf8a72..d78236473725 100644 --- a/trampoline/pom.xml +++ b/trampoline/pom.xml @@ -35,11 +35,6 @@ </parent> <artifactId>trampoline</artifactId> <dependencies> - <dependency> - <groupId>junit</groupId> - <artifactId>junit</artifactId> - <scope>test</scope> - </dependency> <dependency> <groupId>org.junit.jupiter</groupId> diff --git a/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java b/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java index 36ad73e3e961..16e34ff10e01 100644 --- a/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java +++ b/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java @@ -98,12 +98,12 @@ public T get() { return trampoline(this); } - T trampoline(final Trampoline<T> trampoline) { + private T trampoline(final Trampoline<T> trampoline) { return Stream.iterate(trampoline, Trampoline::jump) .filter(Trampoline::complete) .findFirst() .map(Trampoline::result) - .orElseThrow(); + .get(); } }; }

diff --git a/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java b/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java index c5d6571cdd51..664a95634f5c 100644 --- a/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java +++ b/trampoline/src/test/java/com/iluwatar/trampoline/TrampolineAppTest.java @@ -23,10 +23,9 @@ package com.iluwatar.trampoline; -import static org.junit.Assert.assertEquals; - -import org.junit.Test; +import static org.junit.jupiter.api.Assertions.assertEquals; +import org.junit.jupiter.api.Test; /** * Test for trampoline pattern. @@ -37,7 +36,7 @@ public class TrampolineAppTest { @Test public void testTrampolineWithFactorialFunction() { long result = TrampolineApp.loop(10, 1).result(); - assertEquals("Be equal", 3628800, result); + assertEquals(3_628_800, result); } } \ No newline at end of file

test

train

iluwatar

train

iluwatar/java-design-patterns/1500_1542

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1500

iluwatar/java-design-patterns/1542

c3c90e2bd451cdd60947704d1250c8b245881199

903453229cb7d5996f4f52a5f5d88f34e6eb1d5a

Use the same JUnit version everywhere

At the moment there are some modules that are still using JUnit 4. Most of the codebase uses JUnit 5, but even with that there are different versions. For example `unit-of-work` and `partial-response` declare their own versions. In this ticket let's try to apply the same version of JUnit 5 everywhere upgrading from JUnit 4 where needed. ## This issue has been partially addressed using #1542 and #1668 Tests from two modules [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) and [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) are not being executed. Respective issues have been opened for resolving the tests in favour of these two modules. - [x] #1667 against [**serverless**](https://github.com/iluwatar/java-design-patterns/tree/master/serverless) - [ ] #1669 against [**naked-objects**](https://github.com/iluwatar/java-design-patterns/tree/master/naked-objects) Resolving these two issues should close this [current issue](https://github.com/iluwatar/java-design-patterns/issues/1500)

diff --git a/pom.xml b/pom.xml index 48fa6fdcf801..8b00646c5e2b 100644 --- a/pom.xml +++ b/pom.xml @@ -41,8 +41,8 @@ <spring-data.version>2.0.14.RELEASE</spring-data.version> <h2.version>1.4.190</h2.version> <junit.version>4.12</junit.version> - <junit-jupiter.version>5.5.2</junit-jupiter.version> - <junit-vintage.version>${junit.version}.2</junit-vintage.version> + <junit-jupiter.version>5.7.1</junit-jupiter.version> + <junit-vintage.version>${junit-jupiter.version}</junit-vintage.version> <sping-test-junit5.version>1.0.2</sping-test-junit5.version> <compiler.version>3.8.1</compiler.version> <jacoco.version>0.8.6</jacoco.version> @@ -274,12 +274,6 @@ <artifactId>camel-stream</artifactId> <version>${camel.version}</version> </dependency> - <dependency> - <groupId>junit</groupId> - <artifactId>junit</artifactId> - <version>${junit.version}</version> - <scope>test</scope> - </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-api</artifactId> diff --git a/saga/pom.xml b/saga/pom.xml index 07d327885258..80eb70f752ad 100644 --- a/saga/pom.xml +++ b/saga/pom.xml @@ -35,11 +35,6 @@ <artifactId>saga</artifactId> <dependencies> - <dependency> - <groupId>junit</groupId> - <artifactId>junit</artifactId> - <scope>test</scope> - </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> diff --git a/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java b/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java index b28a148039cb..1d2ea91d31a6 100644 --- a/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java +++ b/trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java @@ -98,7 +98,7 @@ public T get() { return trampoline(this); } - private T trampoline(final Trampoline<T> trampoline) { + T trampoline(final Trampoline<T> trampoline) { return Stream.iterate(trampoline, Trampoline::jump) .filter(Trampoline::complete) .findFirst() diff --git a/update-method/pom.xml b/update-method/pom.xml index b49ab3c070b2..b70520a99898 100644 --- a/update-method/pom.xml +++ b/update-method/pom.xml @@ -35,10 +35,6 @@ <artifactId>update-method</artifactId> <dependencies> - <dependency> - <groupId>junit</groupId> - <artifactId>junit</artifactId> - </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId>

diff --git a/saga/src/test/java/com/iluwatar/saga/choreography/SagaApplicationTest.java b/saga/src/test/java/com/iluwatar/saga/choreography/SagaApplicationTest.java index 52b407b57294..67ac0f2fae1d 100644 --- a/saga/src/test/java/com/iluwatar/saga/choreography/SagaApplicationTest.java +++ b/saga/src/test/java/com/iluwatar/saga/choreography/SagaApplicationTest.java @@ -23,18 +23,19 @@ package com.iluwatar.saga.choreography; -import com.iluwatar.saga.orchestration.SagaApplication; -import org.junit.Test; - import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; +import com.iluwatar.saga.orchestration.SagaApplication; +import org.junit.jupiter.api.Test; + /*** * empty test */ -public class SagaApplicationTest { +class SagaApplicationTest { + @Test - public void shouldExecuteWithoutException() { + void shouldExecuteWithoutException() { assertDoesNotThrow(() -> SagaApplication.main(new String[]{})); } -} \ No newline at end of file +} diff --git a/saga/src/test/java/com/iluwatar/saga/choreography/SagaChoreographyTest.java b/saga/src/test/java/com/iluwatar/saga/choreography/SagaChoreographyTest.java index b1ddcf13f465..749a66ac5617 100644 --- a/saga/src/test/java/com/iluwatar/saga/choreography/SagaChoreographyTest.java +++ b/saga/src/test/java/com/iluwatar/saga/choreography/SagaChoreographyTest.java @@ -23,24 +23,25 @@ package com.iluwatar.saga.choreography; -import org.junit.Assert; -import org.junit.Test; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertEquals; /** * test to check choreography saga */ -public class SagaChoreographyTest { +class SagaChoreographyTest { @Test - public void executeTest() { + void executeTest() { var sd = serviceDiscovery(); var service = sd.findAny(); var badOrderSaga = service.execute(newSaga("bad_order")); var goodOrderSaga = service.execute(newSaga("good_order")); - Assert.assertEquals(badOrderSaga.getResult(), Saga.SagaResult.ROLLBACKED); - Assert.assertEquals(goodOrderSaga.getResult(), Saga.SagaResult.FINISHED); + assertEquals(Saga.SagaResult.ROLLBACKED, badOrderSaga.getResult()); + assertEquals(Saga.SagaResult.FINISHED, goodOrderSaga.getResult()); } private static Saga newSaga(Object value) { diff --git a/saga/src/test/java/com/iluwatar/saga/orchestration/SagaApplicationTest.java b/saga/src/test/java/com/iluwatar/saga/orchestration/SagaApplicationTest.java index 1ebb9de4428a..29a2f7eb60a8 100644 --- a/saga/src/test/java/com/iluwatar/saga/orchestration/SagaApplicationTest.java +++ b/saga/src/test/java/com/iluwatar/saga/orchestration/SagaApplicationTest.java @@ -23,15 +23,15 @@ package com.iluwatar.saga.orchestration; -import org.junit.Test; +import org.junit.jupiter.api.Test; /** * empty test */ -public class SagaApplicationTest { +class SagaApplicationTest { @Test - public void mainTest() { + void mainTest() { SagaApplication.main(new String[]{}); } -} \ No newline at end of file +} diff --git a/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorInternallyTest.java b/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorInternallyTest.java index 6a1a257df716..23635d1e6665 100644 --- a/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorInternallyTest.java +++ b/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorInternallyTest.java @@ -23,28 +23,30 @@ package com.iluwatar.saga.orchestration; +import org.junit.jupiter.api.Test; + import static com.iluwatar.saga.orchestration.Saga.Result; +import static org.junit.jupiter.api.Assertions.assertArrayEquals; +import static org.junit.jupiter.api.Assertions.assertEquals; import java.util.ArrayList; import java.util.List; -import org.junit.Assert; -import org.junit.Test; /** * test to test orchestration logic */ -public class SagaOrchestratorInternallyTest { +class SagaOrchestratorInternallyTest { private final List<String> records = new ArrayList<>(); @Test - public void executeTest() { + void executeTest() { var sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery()); var result = sagaOrchestrator.execute(1); - Assert.assertEquals(result, Result.ROLLBACK); - Assert.assertArrayEquals( - records.toArray(new String[]{}), - new String[]{"+1", "+2", "+3", "+4", "-4", "-3", "-2", "-1"}); + assertEquals(Result.ROLLBACK, result); + assertArrayEquals( + new String[]{"+1", "+2", "+3", "+4", "-4", "-3", "-2", "-1"}, + records.toArray(new String[]{})); } private static Saga newSaga() { diff --git a/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorTest.java b/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorTest.java index 7dd4c318059a..2a1da99810e4 100644 --- a/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorTest.java +++ b/saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorTest.java @@ -23,22 +23,23 @@ package com.iluwatar.saga.orchestration; -import org.junit.Assert; -import org.junit.Test; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertEquals; /** * test to check general logic */ -public class SagaOrchestratorTest { +class SagaOrchestratorTest { @Test - public void execute() { + void execute() { SagaOrchestrator sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery()); Saga.Result badOrder = sagaOrchestrator.execute("bad_order"); Saga.Result crashedOrder = sagaOrchestrator.execute("crashed_order"); - Assert.assertEquals(badOrder, Saga.Result.ROLLBACK); - Assert.assertEquals(crashedOrder, Saga.Result.CRASHED); + assertEquals(Saga.Result.ROLLBACK, badOrder); + assertEquals(Saga.Result.CRASHED, crashedOrder); } private static Saga newSaga() { diff --git a/update-method/src/test/java/com/iluwatar/updatemethod/AppTest.java b/update-method/src/test/java/com/iluwatar/updatemethod/AppTest.java index 6158e74912bc..9c5c2a1e2bb2 100644 --- a/update-method/src/test/java/com/iluwatar/updatemethod/AppTest.java +++ b/update-method/src/test/java/com/iluwatar/updatemethod/AppTest.java @@ -23,14 +23,14 @@ package com.iluwatar.updatemethod; -import org.junit.Test; +import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; -public class AppTest { +class AppTest { @Test - public void shouldExecuteApplicationWithoutException() { + void shouldExecuteApplicationWithoutException() { assertDoesNotThrow(() -> App.main(new String[]{})); } } diff --git a/update-method/src/test/java/com/iluwatar/updatemethod/SkeletonTest.java b/update-method/src/test/java/com/iluwatar/updatemethod/SkeletonTest.java index 2562180b8f56..a30dd26cb712 100644 --- a/update-method/src/test/java/com/iluwatar/updatemethod/SkeletonTest.java +++ b/update-method/src/test/java/com/iluwatar/updatemethod/SkeletonTest.java @@ -23,56 +23,60 @@ package com.iluwatar.updatemethod; -import org.junit.After; -import org.junit.Assert; -import org.junit.Before; -import org.junit.Test; +import org.junit.jupiter.api.AfterAll; +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; -public class SkeletonTest { +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; - private Skeleton skeleton; - @Before - public void setup() { +class SkeletonTest { + + private static Skeleton skeleton; + + @BeforeAll + public static void setup() { skeleton = new Skeleton(1); } - @After - public void tearDown() { + @AfterAll + public static void tearDown() { skeleton = null; } @Test - public void testUpdateForPatrollingLeft() { + void testUpdateForPatrollingLeft() { skeleton.patrollingLeft = true; skeleton.setPosition(50); skeleton.update(); - Assert.assertEquals(49, skeleton.getPosition()); + assertEquals(49, skeleton.getPosition()); } @Test - public void testUpdateForPatrollingRight() { + void testUpdateForPatrollingRight() { skeleton.patrollingLeft = false; skeleton.setPosition(50); skeleton.update(); - Assert.assertEquals(51, skeleton.getPosition()); + assertEquals(51, skeleton.getPosition()); } @Test - public void testUpdateForReverseDirectionFromLeftToRight() { + void testUpdateForReverseDirectionFromLeftToRight() { skeleton.patrollingLeft = true; skeleton.setPosition(1); skeleton.update(); - Assert.assertEquals(0, skeleton.getPosition()); - Assert.assertEquals(false, skeleton.patrollingLeft); + assertEquals(0, skeleton.getPosition()); + assertFalse(skeleton.patrollingLeft); } @Test - public void testUpdateForReverseDirectionFromRightToLeft() { + void testUpdateForReverseDirectionFromRightToLeft() { skeleton.patrollingLeft = false; skeleton.setPosition(99); skeleton.update(); - Assert.assertEquals(100, skeleton.getPosition()); - Assert.assertEquals(true, skeleton.patrollingLeft); + assertEquals(100, skeleton.getPosition()); + assertTrue(skeleton.patrollingLeft); } } diff --git a/update-method/src/test/java/com/iluwatar/updatemethod/StatueTest.java b/update-method/src/test/java/com/iluwatar/updatemethod/StatueTest.java index eea6bbeb1278..3b28ffd5d3cb 100644 --- a/update-method/src/test/java/com/iluwatar/updatemethod/StatueTest.java +++ b/update-method/src/test/java/com/iluwatar/updatemethod/StatueTest.java @@ -23,36 +23,37 @@ package com.iluwatar.updatemethod; -import org.junit.After; -import org.junit.Assert; -import org.junit.Before; -import org.junit.Test; +import org.junit.jupiter.api.AfterAll; +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; -public class StatueTest { +import static org.junit.jupiter.api.Assertions.assertEquals; - private Statue statue; +class StatueTest { - @Before - public void setup() { + private static Statue statue; + + @BeforeAll + public static void setup() { statue = new Statue(1, 20); } - @After - public void tearDown() { + @AfterAll + public static void tearDown() { statue = null; } @Test - public void testUpdateForPendingShoot() { + void testUpdateForPendingShoot() { statue.frames = 10; statue.update(); - Assert.assertEquals(11, statue.frames); + assertEquals(11, statue.frames); } @Test - public void testUpdateForShooting() { + void testUpdateForShooting() { statue.frames = 19; statue.update(); - Assert.assertEquals(0, statue.frames); + assertEquals(0, statue.frames); } } diff --git a/update-method/src/test/java/com/iluwatar/updatemethod/WorldTest.java b/update-method/src/test/java/com/iluwatar/updatemethod/WorldTest.java index b8d95f140705..843c4a654d21 100644 --- a/update-method/src/test/java/com/iluwatar/updatemethod/WorldTest.java +++ b/update-method/src/test/java/com/iluwatar/updatemethod/WorldTest.java @@ -23,41 +23,44 @@ package com.iluwatar.updatemethod; -import org.junit.After; -import org.junit.Assert; -import org.junit.Before; -import org.junit.Test; +import org.junit.jupiter.api.AfterAll; +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; -public class WorldTest { +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; - private World world; +class WorldTest { - @Before - public void setup() { + private static World world; + + @BeforeAll + public static void setup() { world = new World(); } - @After - public void tearDown() { + @AfterAll + public static void tearDown() { world = null; } @Test - public void testRun() { + void testRun() { world.run(); - Assert.assertEquals(true, world.isRunning); + assertTrue(world.isRunning); } @Test - public void testStop() { + void testStop() { world.stop(); - Assert.assertEquals(false, world.isRunning); + assertFalse(world.isRunning); } @Test - public void testAddEntity() { + void testAddEntity() { var entity = new Skeleton(1); world.addEntity(entity); - Assert.assertEquals(entity, world.entities.get(0)); + assertEquals(entity, world.entities.get(0)); } }

train

train

iluwatar

train

iluwatar/java-design-patterns/1310_1543

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1310

iluwatar/java-design-patterns/1543

428cbc1027594794cc0aaab17be35e3cacb2b117

14c4710435e89218404086816682012eff023497

Registry pattern

https://www.martinfowler.com/eaaCatalog/registry.html https://stackoverflow.com/questions/16744424/whats-the-difference-between-singleton-and-registry-design-pattern https://wiki.c2.com/?RegistryPattern

diff --git a/pom.xml b/pom.xml index e7fd2e4b3f87..86cefa13386a 100644 --- a/pom.xml +++ b/pom.xml @@ -195,6 +195,7 @@ <module>strangler</module> <module>arrange-act-assert</module> <module>transaction-script</module> + <module>registry</module> <module>filterer</module> <module>factory</module> <module>separated-interface</module> diff --git a/registry/README.md b/registry/README.md new file mode 100644 index 000000000000..699c13318263 --- /dev/null +++ b/registry/README.md @@ -0,0 +1,86 @@ +--- +layout: pattern +title: Registry +folder: registry +permalink: /patterns/registry/ +categories: Creational +tags: + - Instantiation +--- + +## Intent +Stores the objects of a single class and provide a global point of access to them. +Similar to Multiton pattern, only difference is that in a registry there is no restriction on the number of objects. + +## Explanation + +In Plain Words + +> Registry is a well-known object that other objects can use to find common objects and services. + +**Programmatic Example** +Below is a `Customer` Class + +```java +public class Customer { + + private final String id; + private final String name; + + public Customer(String id, String name) { + this.id = id; + this.name = name; + } + + public String getId() { + return id; + } + + public String getName() { + return name; + } + +} +``` + +This registry of the `Customer` objects is `CustomerRegistry` +```java +public final class CustomerRegistry { + + private static final CustomerRegistry instance = new CustomerRegistry(); + + public static CustomerRegistry getInstance() { + return instance; + } + + private final Map<String, Customer> customerMap; + + private CustomerRegistry() { + customerMap = new ConcurrentHashMap<>(); + } + + public Customer addCustomer(Customer customer) { + return customerMap.put(customer.getId(), customer); + } + + public Customer getCustomer(String id) { + return customerMap.get(id); + } + +} +``` + +## Class diagram + + +## Applicability +Use Registry pattern when + +* client wants reference of some object, so client can lookup for that object in the object's registry. + +## Consequences +Large number of bulky objects added to registry would result in a lot of memory consumption as objects in the registry are not garbage collected. + +## Credits +* https://www.martinfowler.com/eaaCatalog/registry.html +* https://wiki.c2.com/?RegistryPattern diff --git a/registry/etc/registry.urm.puml b/registry/etc/registry.urm.puml new file mode 100644 index 000000000000..77c6441fe688 --- /dev/null +++ b/registry/etc/registry.urm.puml @@ -0,0 +1,21 @@ +@startuml +package com.iluwatar.registry { + class App { + - LOGGER : Logger {static} + + App() + + main(args : String[]) {static} + } + class Customer { + - id : String + - name : String + + getId() : String + + getName() : String + + toString() : String + } + class CustomerRegistry { + + addCustomer(customer : Customer) + + getCustomer(id : String) + } +} +Customer --> "-addCustomer" CustomerRegistry +@enduml diff --git a/registry/pom.xml b/registry/pom.xml new file mode 100644 index 000000000000..852bcacfd73c --- /dev/null +++ b/registry/pom.xml @@ -0,0 +1,46 @@ +<?xml version="1.0" encoding="UTF-8"?> +<project xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.24.0-SNAPSHOT</version> + </parent> + <artifactId>registry</artifactId> + + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>junit</groupId> + <artifactId>junit</artifactId> + </dependency> + </dependencies> + + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.registry.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> + +</project> diff --git a/registry/src/main/java/com/iluwatar/registry/App.java b/registry/src/main/java/com/iluwatar/registry/App.java new file mode 100644 index 000000000000..a593ce5cc15b --- /dev/null +++ b/registry/src/main/java/com/iluwatar/registry/App.java @@ -0,0 +1,27 @@ +package com.iluwatar.registry; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + /** + * Program entry point. + * + * @param args command line args + */ + public static void main(String[] args) { + CustomerRegistry customerRegistry = CustomerRegistry.getInstance(); + var john = new Customer("1", "John"); + customerRegistry.addCustomer(john); + + var julia = new Customer("2", "Julia"); + customerRegistry.addCustomer(julia); + + LOGGER.info("John {}", customerRegistry.getCustomer("1")); + LOGGER.info("Julia {}", customerRegistry.getCustomer("2")); + } + +} diff --git a/registry/src/main/java/com/iluwatar/registry/Customer.java b/registry/src/main/java/com/iluwatar/registry/Customer.java new file mode 100644 index 000000000000..354999fdf2ce --- /dev/null +++ b/registry/src/main/java/com/iluwatar/registry/Customer.java @@ -0,0 +1,28 @@ +package com.iluwatar.registry; + +public class Customer { + + private final String id; + private final String name; + + public Customer(String id, String name) { + this.id = id; + this.name = name; + } + + public String getId() { + return id; + } + + public String getName() { + return name; + } + + @Override + public String toString() { + return "Customer{" + + "id='" + id + '\'' + + ", name='" + name + '\'' + + '}'; + } +} diff --git a/registry/src/main/java/com/iluwatar/registry/CustomerRegistry.java b/registry/src/main/java/com/iluwatar/registry/CustomerRegistry.java new file mode 100644 index 000000000000..406d616c678c --- /dev/null +++ b/registry/src/main/java/com/iluwatar/registry/CustomerRegistry.java @@ -0,0 +1,28 @@ +package com.iluwatar.registry; + +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; + +public final class CustomerRegistry { + + private static final CustomerRegistry instance = new CustomerRegistry(); + + public static CustomerRegistry getInstance() { + return instance; + } + + private final Map<String, Customer> customerMap; + + private CustomerRegistry() { + customerMap = new ConcurrentHashMap<>(); + } + + public Customer addCustomer(Customer customer) { + return customerMap.put(customer.getId(), customer); + } + + public Customer getCustomer(String id) { + return customerMap.get(id); + } + +}

diff --git a/registry/src/test/java/com/iluwatar/registry/CustomerRegistryTest.java b/registry/src/test/java/com/iluwatar/registry/CustomerRegistryTest.java new file mode 100644 index 000000000000..2919390b9270 --- /dev/null +++ b/registry/src/test/java/com/iluwatar/registry/CustomerRegistryTest.java @@ -0,0 +1,44 @@ +package com.iluwatar.registry; + +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertNotNull; +import static org.junit.jupiter.api.Assertions.assertNull; + +public class CustomerRegistryTest { + + private static CustomerRegistry customerRegistry; + + @BeforeAll + public static void setUp() { + customerRegistry = CustomerRegistry.getInstance(); + } + + @Test + public void shouldBeAbleToAddAndQueryCustomerObjectFromRegistry() { + Customer john = new Customer("1", "john"); + Customer julia = new Customer("2", "julia"); + + customerRegistry.addCustomer(john); + customerRegistry.addCustomer(julia); + + Customer customerWithId1 = customerRegistry.getCustomer("1"); + assertNotNull(customerWithId1); + assertEquals("1", customerWithId1.getId()); + assertEquals("john", customerWithId1.getName()); + + Customer customerWithId2 = customerRegistry.getCustomer("2"); + assertNotNull(customerWithId2); + assertEquals("2", customerWithId2.getId()); + assertEquals("julia", customerWithId2.getName()); + } + + @Test + public void shouldReturnNullWhenQueriedCustomerIsNotInRegistry() { + Customer customerWithId5 = customerRegistry.getCustomer("5"); + assertNull(customerWithId5); + } + +}

train

train

iluwatar

train

iluwatar/java-design-patterns/1569_1570

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1569

iluwatar/java-design-patterns/1570

a94615ac54300326b8912a5a365418caed9306bd

5bc61c8c28e770f9b2805a3dc56bfde5fdbbc238

Data transfer object pattern using Enums

I'm going to implement a DTO pattern using java Enums. In this way the code is going to be more **Type safe**, **Consistent Syntax**, **Consistent Semantics**, and more **Readable & Maintainable**.

diff --git a/data-transfer-object-enum-impl/README.md b/data-transfer-object-enum-impl/README.md new file mode 100644 index 000000000000..7e6dbc365319 --- /dev/null +++ b/data-transfer-object-enum-impl/README.md @@ -0,0 +1,54 @@ +--- +layout: pattern +title: Data Transfer Object +folder: data-transfer-object +permalink: /patterns/data-transfer-object/ +categories: Architectural +tags: + - Performance +--- + +## Intent + +Pass data with multiple attributes in one shot from client to server, to avoid multiple calls to +remote server. + +## Explanation + +Real world example + +> We need to fetch information about customers from remote database. Instead of querying the +> attributes one at a time, we use DTOs to transfer all the relevant attributes in a single shot. + +In plain words + +> Using DTO relevant information can be fetched with a single backend query. + +Wikipedia says + +> In the field of programming a data transfer object (DTO) is an object that carries data between +> processes. The motivation for its use is that communication between processes is usually done +> resorting to remote interfaces (e.g. web services), where each call is an expensive operation. +> Because the majority of the cost of each call is related to the round-trip time between the client +> and the server, one way of reducing the number of calls is to use an object (the DTO) that +> aggregates the data that would have been transferred by the several calls, but that is served by +> one call only. + +## Class diagram + + + +## Applicability + +Use the Data Transfer Object pattern when: + +* The client is asking for multiple information. And the information is related. +* When you want to boost the performance to get resources. +* You want reduced number of remote calls. + +## Credits + +* [Design Pattern - Transfer Object Pattern](https://www.tutorialspoint.com/design_pattern/transfer_object_pattern.htm) +* [Data Transfer Object](https://msdn.microsoft.com/en-us/library/ff649585.aspx) +* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=f27d2644fbe5026ea448791a8ad09c94) +* [Patterns of Enterprise Application Architecture](https://www.amazon.com/gp/product/0321127420/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321127420&linkCode=as2&tag=javadesignpat-20&linkId=014237a67c9d46f384b35e10151956bd) diff --git a/data-transfer-object-enum-impl/etc/data-transfer-object-enum-impl.urm.puml b/data-transfer-object-enum-impl/etc/data-transfer-object-enum-impl.urm.puml new file mode 100644 index 000000000000..e6426c3928df --- /dev/null +++ b/data-transfer-object-enum-impl/etc/data-transfer-object-enum-impl.urm.puml @@ -0,0 +1,129 @@ +@startuml +package com.iluwatar.datatransferenum { + class App { + - LOGGER : Logger {static} + + App() + + main(args : String[]) {static} + } + class Product { + - cost : Double + - id : Long + - name : String + - price : Double + - supplier : String + + Product() + + getCost() : Double + + getId() : Long + + getName() : String + + getPrice() : Double + + getSupplier() : String + + setCost(cost : Double) : Product + + setId(id : Long) : Product + + setName(name : String) : Product + + setPrice(price : Double) : Product + + setSupplier(supplier : String) : Product + + toString() : String + } + enum ProductDTO { + + valueOf(name : String) : ProductDTO {static} + + values() : ProductDTO[] {static} + } + -interface Cost { + + getCost() : Double {abstract} + } + -interface Id { + + getId() : Long {abstract} + } + -interface Name { + + getName() : String {abstract} + } + -interface Price { + + getPrice() : Double {abstract} + } + enum Request { + + valueOf(name : String) : Request {static} + + values() : Request[] {static} + } + class Create { + - cost : Double + - name : String + - price : Double + - supplier : String + + Create() + + getCost() : Double + + getName() : String + + getPrice() : Double + + getSupplier() : String + + setCost(cost : Double) : Create + + setName(name : String) : Create + + setPrice(price : Double) : Create + + setSupplier(supplier : String) : Create + } + enum Response { + + valueOf(name : String) : Response {static} + + values() : Response[] {static} + } + class Private { + - cost : Double + - id : Long + - name : String + - price : Double + + Private() + + getCost() : Double + + getId() : Long + + getName() : String + + getPrice() : Double + + setCost(cost : Double) : Private + + setId(id : Long) : Private + + setName(name : String) : Private + + setPrice(price : Double) : Private + + toString() : String + } + class Public { + - id : Long + - name : String + - price : Double + + Public() + + getId() : Long + + getName() : String + + getPrice() : Double + + setId(id : Long) : Public + + setName(name : String) : Public + + setPrice(price : Double) : Public + + toString() : String + } + -interface Supplier { + + getSupplier() : String {abstract} + } + class ProductResource { + - products : List<Product> + + ProductResource(products : List<Product>) + + getAllProductsForAdmin() : List<Private> + + getAllProductsForCustomer() : List<Public> + + getProducts() : List<Product> + + save(createProductDTO : Create) + } +} +Create ..+ Request +Request ..+ ProductDTO +Private ..+ Response +Supplier ..+ ProductDTO +Name ..+ ProductDTO +ProductResource --> "-products" Product +Public ..+ Response +Id ..+ ProductDTO +Price ..+ ProductDTO +Response ..+ ProductDTO +Cost ..+ ProductDTO +Create ..|> Name +Create ..|> Price +Create ..|> Cost +Create ..|> Supplier +Private ..|> Id +Private ..|> Name +Private ..|> Price +Private ..|> Cost +Public ..|> Id +Public ..|> Name +Public ..|> Price +@enduml diff --git a/data-transfer-object-enum-impl/pom.xml b/data-transfer-object-enum-impl/pom.xml new file mode 100644 index 000000000000..74c8a3a6cf8b --- /dev/null +++ b/data-transfer-object-enum-impl/pom.xml @@ -0,0 +1,61 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + The MIT License + Copyright © 2014-2019 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.24.0-SNAPSHOT</version> + </parent> + <artifactId>data-transfer-object-enum-impl</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.datatransferenum.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> diff --git a/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/App.java b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/App.java new file mode 100644 index 000000000000..9c80d07cc461 --- /dev/null +++ b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/App.java @@ -0,0 +1,59 @@ +package com.iluwatar.datatransferenum; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * The Data Transfer Object pattern is a design pattern in which an data transfer object is used to + * serve related information together to avoid multiple call for each piece of information. + * + * <p>In this example, ({@link App}) as as product details consumer i.e. client to + * request for product details to server. + * + * <p>productResource ({@link ProductResource}) act as server to serve product information. And + * The productDto ({@link ProductDto} is data transfer object to share product information. + */ +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + /** + * Method as act client and request to server for details. + * + * @param args program argument. + */ + public static void main(String[] args) { + Product tv = + new Product().setId(1L).setName("TV").setSupplier("Sony").setPrice(1000D).setCost(1090D); + Product microwave = + new Product().setId(2L).setName("microwave").setSupplier("Delonghi").setPrice(1000D) + .setCost(1090D); + Product refrigerator = + new Product().setId(3L).setName("refrigerator").setSupplier("Botsch").setPrice(1000D) + .setCost(1090D); + Product airConditioner = + new Product().setId(4L).setName("airConditioner").setSupplier("LG").setPrice(1000D) + .setCost(1090D); + List<Product> products = + new ArrayList<>(Arrays.asList(tv, microwave, refrigerator, airConditioner)); + ProductResource productResource = new ProductResource(products); + + LOGGER.info("####### List of products including sensitive data just for admins: \n {}", + Arrays.toString(productResource.getAllProductsForAdmin().toArray())); + LOGGER.info("####### List of products for customers: \n {}", + Arrays.toString(productResource.getAllProductsForCustomer().toArray())); + + LOGGER.info("####### Going to save Sony PS5 ..."); + ProductDto.Request.Create createProductRequestDto = new ProductDto.Request.Create() + .setName("PS5") + .setCost(1000D) + .setPrice(1220D) + .setSupplier("Sony"); + productResource.save(createProductRequestDto); + LOGGER.info("####### List of products after adding PS5: {}", + Arrays.toString(productResource.getProducts().toArray())); + } +} diff --git a/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/Product.java b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/Product.java new file mode 100644 index 000000000000..96758baf4297 --- /dev/null +++ b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/Product.java @@ -0,0 +1,91 @@ +package com.iluwatar.datatransferenum; + +/** + * {@link Product} is a entity class for product entity. This class act as entity in the demo. + */ +public final class Product { + private Long id; + private String name; + private Double price; + private Double cost; + private String supplier; + + /** + * Constructor. + * + * @param id product id + * @param name product name + * @param price product price + * @param cost product cost + * @param supplier product supplier + */ + public Product(Long id, String name, Double price, Double cost, String supplier) { + this.id = id; + this.name = name; + this.price = price; + this.cost = cost; + this.supplier = supplier; + } + + /** + * Constructor. + */ + public Product() { + } + + public Long getId() { + return id; + } + + public Product setId(Long id) { + this.id = id; + return this; + } + + public String getName() { + return name; + } + + public Product setName(String name) { + this.name = name; + return this; + } + + public Double getPrice() { + return price; + } + + public Product setPrice(Double price) { + this.price = price; + return this; + } + + public Double getCost() { + return cost; + } + + public Product setCost(Double cost) { + this.cost = cost; + return this; + } + + public String getSupplier() { + return supplier; + } + + public Product setSupplier(String supplier) { + this.supplier = supplier; + return this; + } + + @Override + public String toString() { + return "Product{" + + "id=" + id + + ", name='" + name + '\'' + + ", price=" + price + + ", cost=" + cost + + ", supplier='" + supplier + '\'' + + '}'; + } +} diff --git a/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/ProductDto.java b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/ProductDto.java new file mode 100644 index 000000000000..49d08d896c29 --- /dev/null +++ b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/ProductDto.java @@ -0,0 +1,264 @@ +package com.iluwatar.datatransferenum; + +/** + * {@link ProductDto} is a data transfer object POJO. + * Instead of sending individual information to + * client We can send related information together in POJO. + * + * <p>Dto will not have any business logic in it. + */ +public enum ProductDto { + ; + + /** + * This is Request class which consist of Create or any other request DTO's + * you might want to use in your API. + */ + public enum Request { + ; + + /** + * This is Create dto class for requesting create new product. + */ + public static final class Create implements Name, Price, Cost, Supplier { + private String name; + private Double price; + private Double cost; + private String supplier; + + @Override + public String getName() { + return name; + } + + public Create setName(String name) { + this.name = name; + return this; + } + + @Override + public Double getPrice() { + return price; + } + + public Create setPrice(Double price) { + this.price = price; + return this; + } + + @Override + public Double getCost() { + return cost; + } + + public Create setCost(Double cost) { + this.cost = cost; + return this; + } + + @Override + public String getSupplier() { + return supplier; + } + + public Create setSupplier(String supplier) { + this.supplier = supplier; + return this; + } + } + } + + /** + * This is Response class which consist of any response DTO's + * you might want to provide to your clients. + */ + public enum Response { + ; + + /** + * This is Public dto class for API response with the lowest data security. + */ + public static final class Public implements Id, Name, Price { + private Long id; + private String name; + private Double price; + + @Override + public Long getId() { + return id; + } + + public Public setId(Long id) { + this.id = id; + return this; + } + + @Override + public String getName() { + return name; + } + + public Public setName(String name) { + this.name = name; + return this; + } + + @Override + public Double getPrice() { + return price; + } + + public Public setPrice(Double price) { + this.price = price; + return this; + } + + @Override + public String toString() { + return "Public{" + + "id=" + + id + + ", name='" + + name + + '\'' + + ", price=" + + price + + '}'; + } + } + + /** + * This is Private dto class for API response with the highest data security. + */ + public static final class Private implements Id, Name, Price, Cost { + private Long id; + private String name; + private Double price; + private Double cost; + + @Override + public Long getId() { + return id; + } + + public Private setId(Long id) { + this.id = id; + return this; + } + + @Override + public String getName() { + return name; + } + + public Private setName(String name) { + this.name = name; + return this; + } + + @Override + public Double getPrice() { + return price; + } + + public Private setPrice(Double price) { + this.price = price; + return this; + } + + @Override + public Double getCost() { + return cost; + } + + public Private setCost(Double cost) { + this.cost = cost; + return this; + } + + @Override + public String toString() { + return "Private{" + + + "id=" + + id + + + ", name='" + + name + + '\'' + + + ", price=" + + price + + + ", cost=" + + cost + + + '}'; + } + } + } + + /** + * Use this interface whenever you want to provide the product Id in your DTO. + */ + private interface Id { + /** + * Unique identifier of the product. + * + * @return : id of the product. + */ + Long getId(); + } + + /** + * Use this interface whenever you want to provide the product Name in your DTO. + */ + private interface Name { + /** + * The name of the product. + * + * @return : name of the product. + */ + String getName(); + } + + /** + * Use this interface whenever you want to provide the product Price in your DTO. + */ + private interface Price { + /** + * The amount we sell a product for. + * <b>This data is not confidential</b> + * + * @return : price of the product. + */ + Double getPrice(); + } + + /** + * Use this interface whenever you want to provide the product Cost in your DTO. + */ + private interface Cost { + /** + * The amount that it costs us to purchase this product + * For the amount we sell a product for, see the {@link Price Price} parameter. + * <b>This data is confidential</b> + * + * @return : cost of the product. + */ + Double getCost(); + } + + /** + * Use this interface whenever you want to provide the product Supplier in your DTO. + */ + private interface Supplier { + /** + * The name of supplier of the product or its manufacturer. + * <b>This data is highly confidential</b> + * + * @return : supplier of the product. + */ + String getSupplier(); + } +} diff --git a/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/ProductResource.java b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/ProductResource.java new file mode 100644 index 000000000000..5940982b1f86 --- /dev/null +++ b/data-transfer-object-enum-impl/src/main/java/com/iluwatar/datatransferenum/ProductResource.java @@ -0,0 +1,71 @@ +package com.iluwatar.datatransferenum; + +import java.util.List; +import java.util.stream.Collectors; + +/** + * The resource class which serves product information. This class act as server in the demo. Which + * has all product details. + */ +public class ProductResource { + private final List<Product> products; + + /** + * Initialise resource with existing products. + * + * @param products initialize resource with existing products. Act as database. + */ + public ProductResource(final List<Product> products) { + this.products = products; + } + + /** + * Get all products. + * + * @return : all products in list but in the scheme of private dto. + */ + public List<ProductDto.Response.Private> getAllProductsForAdmin() { + return products + .stream() + .map(p -> new ProductDto.Response.Private().setId(p.getId()).setName(p.getName()) + .setCost(p.getCost()) + .setPrice(p.getPrice())) + .collect(Collectors.toList()); + } + + /** + * Get all products. + * + * @return : all products in list but in the scheme of public dto. + */ + public List<ProductDto.Response.Public> getAllProductsForCustomer() { + return products + .stream() + .map(p -> new ProductDto.Response.Public().setId(p.getId()).setName(p.getName()) + .setPrice(p.getPrice())) + .collect(Collectors.toList()); + } + + /** + * Save new product. + * + * @param createProductDto save new product to list. + */ + public void save(ProductDto.Request.Create createProductDto) { + products.add(new Product() + .setId((long) (products.size() + 1)) + .setName(createProductDto.getName()) + .setSupplier(createProductDto.getSupplier()) + .setPrice(createProductDto.getPrice()) + .setCost(createProductDto.getCost())); + } + + /** + * List of all products in an entity representation. + * + * @return : all the products entity that stored in the products list + */ + public List<Product> getProducts() { + return products; + } +} diff --git a/pom.xml b/pom.xml index 86cefa13386a..b6556245b72b 100644 --- a/pom.xml +++ b/pom.xml @@ -199,6 +199,7 @@ <module>filterer</module> <module>factory</module> <module>separated-interface</module> + <module>data-transfer-object-enum-impl</module> </modules> <repositories>

diff --git a/data-transfer-object-enum-impl/src/test/java/com/iluwatar/datatransferenum/AppTest.java b/data-transfer-object-enum-impl/src/test/java/com/iluwatar/datatransferenum/AppTest.java new file mode 100644 index 000000000000..bba131e64163 --- /dev/null +++ b/data-transfer-object-enum-impl/src/test/java/com/iluwatar/datatransferenum/AppTest.java @@ -0,0 +1,44 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.datatransferenum; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + + +import org.junit.jupiter.api.Test; + +class AppTest { + + /** + * Issue: Add at least one assertion to this test case. + * <p> + * Solution: Inserted assertion to check whether the execution of the main method in {@link App#main(String[])} + * throws an exception. + */ + + @Test + void shouldExecuteApplicationWithoutException() { + assertDoesNotThrow(() -> App.main(new String[] {})); + } +}

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 Lines 83-84: Could not find CarSimpleFactory. Isn't it CarsFactory?

diff --git a/factory/README.md b/factory/README.md index a1b6208fd736..0112c92c0f06 100644 --- a/factory/README.md +++ b/factory/README.md @@ -81,7 +81,7 @@ public enum CarType { } ``` Then we have the static method `getCar` to create car objects encapsulated in the factory class -`CarSimpleFactory`. +`CarsFactory`. ```java public class CarsFactory {

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careless grammer mistake in zh/decorator/README.md

line 36:程序mple. First of all we have a simple troll implementing the troll interface should be 程序example. First of all we have a simple troll implementing the troll interface Thank you!

diff --git a/zh/bridge/README.md b/zh/bridge/README.md new file mode 100644 index 000000000000..cd9f40ac496a --- /dev/null +++ b/zh/bridge/README.md @@ -0,0 +1,205 @@ +--- +layout: pattern +title: Bridge +folder: bridge +permalink: /patterns/bridge/ +categories: Structural +tags: + - Gang of Four +--- + +## 又被称为 + +手柄/身体模式 + +## 目的 + +将抽象与其实现分离，以便二者可以独立变化。 + +## 解释 + +真实世界例子 + +> 考虑一下你拥有一种具有不同附魔的武器，并且应该允许将具有不同附魔的不同武器混合使用。 你会怎么做？ 为每个附魔创建每种武器的多个副本，还是只是创建单独的附魔并根据需要为武器设置它？ 桥接模式使您可以进行第二次操作。 + +通俗的说 + +> 桥接模式是一个更推荐组合而不是继承的模式。将实现细节从一个层次结构推送到具有单独层次结构的另一个对象。 + +维基百科说 + +> 桥接模式是软件工程中使用的一种设计模式，旨在“将抽象与其实现分离，从而使两者可以独立变化” + +**程序示例** + +翻译一下上面的武器示例。下面我们有武器的类层级： + +```java +public interface Weapon { + void wield(); + void swing(); + void unwield(); + Enchantment getEnchantment(); +} + +public class Sword implements Weapon { + + private final Enchantment enchantment; + + public Sword(Enchantment enchantment) { + this.enchantment = enchantment; + } + + @Override + public void wield() { + LOGGER.info("The sword is wielded."); + enchantment.onActivate(); + } + + @Override + public void swing() { + LOGGER.info("The sword is swinged."); + enchantment.apply(); + } + + @Override + public void unwield() { + LOGGER.info("The sword is unwielded."); + enchantment.onDeactivate(); + } + + @Override + public Enchantment getEnchantment() { + return enchantment; + } +} + +public class Hammer implements Weapon { + + private final Enchantment enchantment; + + public Hammer(Enchantment enchantment) { + this.enchantment = enchantment; + } + + @Override + public void wield() { + LOGGER.info("The hammer is wielded."); + enchantment.onActivate(); + } + + @Override + public void swing() { + LOGGER.info("The hammer is swinged."); + enchantment.apply(); + } + + @Override + public void unwield() { + LOGGER.info("The hammer is unwielded."); + enchantment.onDeactivate(); + } + + @Override + public Enchantment getEnchantment() { + return enchantment; + } +} +``` + +这里是单独的附魔类结构： + +```java +public interface Enchantment { + void onActivate(); + void apply(); + void onDeactivate(); +} + +public class FlyingEnchantment implements Enchantment { + + @Override + public void onActivate() { + LOGGER.info("The item begins to glow faintly."); + } + + @Override + public void apply() { + LOGGER.info("The item flies and strikes the enemies finally returning to owner's hand."); + } + + @Override + public void onDeactivate() { + LOGGER.info("The item's glow fades."); + } +} + +public class SoulEatingEnchantment implements Enchantment { + + @Override + public void onActivate() { + LOGGER.info("The item spreads bloodlust."); + } + + @Override + public void apply() { + LOGGER.info("The item eats the soul of enemies."); + } + + @Override + public void onDeactivate() { + LOGGER.info("Bloodlust slowly disappears."); + } +} +``` + +这里是两种层次结构的实践： + +```java +var enchantedSword = new Sword(new SoulEatingEnchantment()); +enchantedSword.wield(); +enchantedSword.swing(); +enchantedSword.unwield(); +// The sword is wielded. +// The item spreads bloodlust. +// The sword is swinged. +// The item eats the soul of enemies. +// The sword is unwielded. +// Bloodlust slowly disappears. + +var hammer = new Hammer(new FlyingEnchantment()); +hammer.wield(); +hammer.swing(); +hammer.unwield(); +// The hammer is wielded. +// The item begins to glow faintly. +// The hammer is swinged. +// The item flies and strikes the enemies finally returning to owner's hand. +// The hammer is unwielded. +// The item's glow fades. +``` + + + +## 类图 + + + +## 适用性 + +使用桥接模式当 + +* 你想永久性的避免抽象和他的实现之间的绑定。有可能是这种情况，当实现需要被选择或者在运行时切换。 +* 抽象和他们的实现应该能通过写子类来扩展。这种情况下，桥接模式让你可以组合不同的抽象和实现并独立的扩展他们。 +* 对抽象的实现的改动应当不会对客户产生影响；也就是说，他们的代码不必重新编译。 +* 你有种类繁多的类。这样的类层次结构表明需要将一个对象分为两部分。Rumbaugh 使用术语“嵌套归纳”来指代这种类层次结构。 +* 你想在多个对象间分享一种实现（可能使用引用计数），这个事实应该对客户隐藏。一个简单的示例是Coplien的String类，其中多个对象可以共享同一字符串表示形式 + +## 教程 + +* [Bridge Pattern Tutorial](https://www.journaldev.com/1491/bridge-design-pattern-java) + +## 鸣谢 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) diff --git a/zh/callback/README.md b/zh/callback/README.md new file mode 100644 index 000000000000..a70a6a7c2210 --- /dev/null +++ b/zh/callback/README.md @@ -0,0 +1,79 @@ +--- +layout: pattern +title: Callback +folder: callback +permalink: /patterns/callback/ +categories: Idiom +tags: + - Reactive +--- + +## 目的 +回调是一部分被当为参数来传递给其他代码的可执行代码，接收方的代码可以在一些方便的时候来调用它。 + +## 解释 + +真实世界例子 + +> 我们需要被通知当执行的任务结束时。我们为调用者传递一个回调方法然后等它调用通知我们。 + +通俗的讲 + + +> 回调是一个用来传递给调用者的方法，它将在定义的时刻被调用。 + +维基百科说 + +> 在计算机编程中，回调又被称为“稍后调用”函数，可以是任何可执行的代码用来作为参数传递给其他代码；其它代码被期望在给定时间内调用回调方法。 + +**编程示例** + +回调是一个只有一个方法的简单接口。 + +```java +public interface Callback { + + void call(); +} +``` + +下面我们定义一个任务它将在任务执行完成后执行回调。 + +```java +public abstract class Task { + + final void executeWith(Callback callback) { + execute(); + Optional.ofNullable(callback).ifPresent(Callback::call); + } + + public abstract void execute(); +} + +public final class SimpleTask extends Task { + + private static final Logger LOGGER = getLogger(SimpleTask.class); + + @Override + public void execute() { + LOGGER.info("Perform some important activity and after call the callback method."); + } +} +``` + +最后这里是我们如何执行一个任务然后接收一个回调当它完成时。 + +```java + var task = new SimpleTask(); + task.executeWith(() -> LOGGER.info("I'm done now.")); +``` +## 类图 + + +## 适用性 +使用回调模式当 +* 当一些同步或异步架构动作必须在一些定义好的活动执行后执行时。 + +## Java例子 + +* [CyclicBarrier](http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/CyclicBarrier.html#CyclicBarrier%28int,%20java.lang.Runnable%29) 构造函数可以接受回调，该回调将在每次障碍被触发时触发。 diff --git a/zh/command/README.md b/zh/command/README.md new file mode 100644 index 000000000000..2c4f03a25997 --- /dev/null +++ b/zh/command/README.md @@ -0,0 +1,253 @@ +--- +layout: pattern +title: Command +folder: command +permalink: /patterns/command/ +categories: Behavioral +tags: + - Gang of Four +--- + +## 或称 +行动, 事务模式 + +## 目的 +将请求封装为对象，从而使你可以将具有不同请求的客户端参数化，队列或记录请求，并且支持可撤销操作。 + +## 解释 +真实世界例子 + +> 有一个巫师在地精上施放咒语。咒语在地精上一一执行。第一个咒语使地精缩小，第二个使他不可见。然后巫师将咒语一个个的反转。这里的每一个咒语都是一个可撤销的命令对象。 + +用通俗的话说 + +> 用命令对象的方式存储请求以在将来时可以执行它或撤销它。 + +维基百科说 + +> 在面向对象编程中，命令模式是一种行为型设计模式，它把在稍后执行的一个动作或触发的一个事件所需要的所有信息封装到一个对象中。 + +**编程示例** + +这是巫师和地精的示例代码。让我们从巫师类开始。 + +```java +public class Wizard { + + private static final Logger LOGGER = LoggerFactory.getLogger(Wizard.class); + + private final Deque<Command> undoStack = new LinkedList<>(); + private final Deque<Command> redoStack = new LinkedList<>(); + + public Wizard() {} + + public void castSpell(Command command, Target target) { + LOGGER.info("{} casts {} at {}", this, command, target); + command.execute(target); + undoStack.offerLast(command); + } + + public void undoLastSpell() { + if (!undoStack.isEmpty()) { + var previousSpell = undoStack.pollLast(); + redoStack.offerLast(previousSpell); + LOGGER.info("{} undoes {}", this, previousSpell); + previousSpell.undo(); + } + } + + public void redoLastSpell() { + if (!redoStack.isEmpty()) { + var previousSpell = redoStack.pollLast(); + undoStack.offerLast(previousSpell); + LOGGER.info("{} redoes {}", this, previousSpell); + previousSpell.redo(); + } + } + + @Override + public String toString() { + return "Wizard"; + } +} +``` + +接下来我们介绍咒语层级 + +```java +public interface Command { + + void execute(Target target); + + void undo(); + + void redo(); + + String toString(); +} + +public class InvisibilitySpell implements Command { + + private Target target; + + @Override + public void execute(Target target) { + target.setVisibility(Visibility.INVISIBLE); + this.target = target; + } + + @Override + public void undo() { + if (target != null) { + target.setVisibility(Visibility.VISIBLE); + } + } + + @Override + public void redo() { + if (target != null) { + target.setVisibility(Visibility.INVISIBLE); + } + } + + @Override + public String toString() { + return "Invisibility spell"; + } +} + +public class ShrinkSpell implements Command { + + private Size oldSize; + private Target target; + + @Override + public void execute(Target target) { + oldSize = target.getSize(); + target.setSize(Size.SMALL); + this.target = target; + } + + @Override + public void undo() { + if (oldSize != null && target != null) { + var temp = target.getSize(); + target.setSize(oldSize); + oldSize = temp; + } + } + + @Override + public void redo() { + undo(); + } + + @Override + public String toString() { + return "Shrink spell"; + } +} +``` + +最后我们有咒语的目标地精。 + +```java +public abstract class Target { + + private static final Logger LOGGER = LoggerFactory.getLogger(Target.class); + + private Size size; + + private Visibility visibility; + + public Size getSize() { + return size; + } + + public void setSize(Size size) { + this.size = size; + } + + public Visibility getVisibility() { + return visibility; + } + + public void setVisibility(Visibility visibility) { + this.visibility = visibility; + } + + @Override + public abstract String toString(); + + public void printStatus() { + LOGGER.info("{}, [size={}] [visibility={}]", this, getSize(), getVisibility()); + } +} + +public class Goblin extends Target { + + public Goblin() { + setSize(Size.NORMAL); + setVisibility(Visibility.VISIBLE); + } + + @Override + public String toString() { + return "Goblin"; + } + +} +``` + +最后是整个示例的实践。 + +```java +var wizard = new Wizard(); +var goblin = new Goblin(); +goblin.printStatus(); +// Goblin, [size=normal] [visibility=visible] +wizard.castSpell(new ShrinkSpell(), goblin); +// Wizard casts Shrink spell at Goblin +goblin.printStatus(); +// Goblin, [size=small] [visibility=visible] +wizard.castSpell(new InvisibilitySpell(), goblin); +// Wizard casts Invisibility spell at Goblin +goblin.printStatus(); +// Goblin, [size=small] [visibility=invisible] +wizard.undoLastSpell(); +// Wizard undoes Invisibility spell +goblin.printStatus(); +// Goblin, [size=small] [visibility=visible] +``` + +## 类图 + + +## 适用性 +使用命令模式当你想 + +* 通过操作将对象参数化。您可以使用回调函数（即，已在某处注册以便稍后调用的函数）以过程语言表示这种参数化。命令是回调的一种面向对象替代方案。 +* 在不同的时间指定，排队和执行请求。一个命令对象的生存期可以独立于原始请求。如果请求的接收方可以以地址空间无关的方式来表示，那么你可以将请求的命令对象传输到其他进程并在那里执行请求。 +* 支持撤销。命令的执行操作可以在命令本身中存储状态以反转其效果。命令接口必须有添加的反执行操作，该操作可以逆转上一次执行调用的效果。执行的命令存储在历史列表中。无限撤消和重做通过分别向后和向前遍历此列表来实现，分别调用unexecute和execute。 +* 支持日志记录更改，以便在系统崩溃时可以重新应用它们。通过使用加载和存储操作扩展命令接口，你可以保留更改的永久日志。从崩溃中恢复涉及从磁盘重新加载记录的命令，并通过执行操作重新执行它们。 +* 通过原始的操作来构建一个以高级操作围绕的系统。这种结构在支持事务的信息系统中很常见。事务封装了一组数据更改。命令模式提供了一种对事务进行建模的方法。命令具有公共接口，让你以相同的方式调用所有事务。该模式还可以通过新的事务来轻松扩展系统。 + +## 典型用例 + +* 保留请求历史 +* 实现回调功能 +* 实现撤销功能 + +## Java世界例子 + +* [java.lang.Runnable](http://docs.oracle.com/javase/8/docs/api/java/lang/Runnable.html) +* [org.junit.runners.model.Statement](https://github.com/junit-team/junit4/blob/master/src/main/java/org/junit/runners/model/Statement.java) +* [Netflix Hystrix](https://github.com/Netflix/Hystrix/wiki) +* [javax.swing.Action](http://docs.oracle.com/javase/8/docs/api/javax/swing/Action.html) + +## 鸣谢 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) +* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7) +* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=f27d2644fbe5026ea448791a8ad09c94) diff --git a/zh/decorator/README.md b/zh/decorator/README.md index ef23eda0b951..6163017afb0f 100644 --- a/zh/decorator/README.md +++ b/zh/decorator/README.md @@ -33,8 +33,6 @@ tags: 以巨魔的为例。首先我有有一个简单的巨魔，实现了巨魔接口。 -程序mple. First of all we have a simple troll implementing the troll interface - ```java public interface Troll { void attack(); diff --git a/zh/dependency-injection/README.md b/zh/dependency-injection/README.md new file mode 100644 index 000000000000..061a55425836 --- /dev/null +++ b/zh/dependency-injection/README.md @@ -0,0 +1,101 @@ +--- +layout: pattern +title: Dependency Injection +folder: dependency-injection +permalink: /patterns/dependency-injection/ +categories: Creational +tags: + - Decoupling +--- + +## 目的 + +依赖注入是一种软件设计模式，其中一个或多个依赖项（或服务）被注入或通过引用传递到一个依赖对象（或客户端）中，并成为客户端状态的一部分。该模式将客户的依赖关系的创建与其自身的行为分开，这使程序设计可以松散耦合，并遵循控制反转和单一职责原则。 + +## 解释 + +真实世界例子 + +> 老巫师喜欢不时地装满烟斗抽烟。 但是，他不想只依赖一个烟草品牌，而是希望能够互换使用它们。 + +通俗的说 + +> 依赖注入将客户端依赖的创建与其自身行为分开。 + +维基百科说 + +> 在软件工程中，依赖注入是一种对象接收其依赖的其他对象的技术。 这些其他对象称为依赖项。 + +**程序示例** + +先介绍一下烟草接口和具体的品牌。 + +```java +public abstract class Tobacco { + + private static final Logger LOGGER = LoggerFactory.getLogger(Tobacco.class); + + public void smoke(Wizard wizard) { + LOGGER.info("{} smoking {}", wizard.getClass().getSimpleName(), + this.getClass().getSimpleName()); + } +} + +public class SecondBreakfastTobacco extends Tobacco { +} + +public class RivendellTobacco extends Tobacco { +} + +public class OldTobyTobacco extends Tobacco { +} +``` + +下面是老巫师的类的层次结构。 + +```java +public interface Wizard { + + void smoke(); +} + +public class AdvancedWizard implements Wizard { + + private final Tobacco tobacco; + + public AdvancedWizard(Tobacco tobacco) { + this.tobacco = tobacco; + } + + @Override + public void smoke() { + tobacco.smoke(this); + } +} +``` + +最后我们可以看到给老巫师任意品牌的烟草是多么的简单。 + +```java + var advancedWizard = new AdvancedWizard(new SecondBreakfastTobacco()); + advancedWizard.smoke(); +``` + +## 类图 + + + +## 适用性 + +使用依赖注入当： + +- 当你需要从对象中移除掉具体的实现内容时 + +* 使用模拟对象或存根隔离地启用类的单元测试 + +## 鸣谢 + +* [Dependency Injection Principles, Practices, and Patterns](https://www.amazon.com/gp/product/161729473X/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=161729473X&linkId=57079257a5c7d33755493802f3b884bd) +* [Clean Code: A Handbook of Agile Software Craftsmanship](https://www.amazon.com/gp/product/0132350882/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0132350882&linkCode=as2&tag=javadesignpat-20&linkId=2c390d89cc9e61c01b9e7005c7842871) +* [Java 9 Dependency Injection: Write loosely coupled code with Spring 5 and Guice](https://www.amazon.com/gp/product/1788296257/ref=as_li_tl?ie=UTF8&tag=javadesignpat-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=1788296257&linkId=4e9137a3bf722a8b5b156cce1eec0fc1) +* [Google Guice Tutorial: Open source Java based dependency injection framework](https://www.amazon.com/gp/product/B083P7DZ8M/ref=as_li_tl?ie=UTF8&tag=javadesignpat-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B083P7DZ8M&linkId=04f0f902c877921e45215b624a124bfe) diff --git a/zh/iterator/README.md b/zh/iterator/README.md new file mode 100644 index 000000000000..0b9db9e43769 --- /dev/null +++ b/zh/iterator/README.md @@ -0,0 +1,134 @@ +--- +layout: pattern +title: Iterator +folder: iterator +permalink: /patterns/iterator/ +categories: Behavioral +tags: + - Gang of Four +--- + +## 又被称为 +游标 + +## 目的 +提供一种在不暴露其基础表示的情况下顺序访问聚合对象的元素的方法。 + +## 解释 + +真实世界例子 + +> 百宝箱包含一组魔法物品。有多种物品，例如戒指，药水和武器。可以使用藏宝箱提供的迭代器按类型浏览商品。 + +通俗地说 + +> 容器可以提供与表示形式无关的迭代器接口，以提供对元素的访问。 + +维基百科说 + +> 在面向对象的编程中，迭代器模式是一种设计模式，其中迭代器用于遍历容器并访问容器的元素。 + +**程序示例** + +在我们的示例中包含物品的藏宝箱是主要类。 + +```java +public class TreasureChest { + + private final List<Item> items; + + public TreasureChest() { + items = List.of( + new Item(ItemType.POTION, "Potion of courage"), + new Item(ItemType.RING, "Ring of shadows"), + new Item(ItemType.POTION, "Potion of wisdom"), + new Item(ItemType.POTION, "Potion of blood"), + new Item(ItemType.WEAPON, "Sword of silver +1"), + new Item(ItemType.POTION, "Potion of rust"), + new Item(ItemType.POTION, "Potion of healing"), + new Item(ItemType.RING, "Ring of armor"), + new Item(ItemType.WEAPON, "Steel halberd"), + new Item(ItemType.WEAPON, "Dagger of poison")); + } + + public Iterator<Item> iterator(ItemType itemType) { + return new TreasureChestItemIterator(this, itemType); + } + + public List<Item> getItems() { + return new ArrayList<>(items); + } +} + +public class Item { + + private ItemType type; + private final String name; + + public Item(ItemType type, String name) { + this.setType(type); + this.name = name; + } + + @Override + public String toString() { + return name; + } + + public ItemType getType() { + return type; + } + + public final void setType(ItemType type) { + this.type = type; + } +} + +public enum ItemType { + + ANY, WEAPON, RING, POTION + +} +``` + +迭代器接口极度简单。 + +```java +public interface Iterator<T> { + + boolean hasNext(); + + T next(); +} +``` + +在以下示例中，我们遍历在宝箱中找到的戒指类型物品。 + +```java +var itemIterator = TREASURE_CHEST.iterator(ItemType.RING); +while (itemIterator.hasNext()) { + LOGGER.info(itemIterator.next().toString()); +} +// Ring of shadows +// Ring of armor +``` + +## 类图 + + +## 适用性 +以下情况使用迭代器模式 + +* 在不暴露其内部表示的情况下访问聚合对象的内容 +* 为了支持聚合对象的多种遍历方式 +* 提供一个遍历不同聚合结构的统一接口 + +## Java世界例子 + +* [java.util.Iterator](http://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html) +* [java.util.Enumeration](http://docs.oracle.com/javase/8/docs/api/java/util/Enumeration.html) + +## 鸣谢 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) diff --git a/zh/state/README.md b/zh/state/README.md new file mode 100644 index 000000000000..6b46510e08bf --- /dev/null +++ b/zh/state/README.md @@ -0,0 +1,155 @@ +--- +layout: pattern +title: State +folder: state +permalink: /patterns/state/ +categories: Behavioral +tags: + - Gang of Four +--- + +## 又被称为 +对象状态 + +## 目的 +允许对象在内部状态改变时改变它的行为。对象看起来好像修改了它的类。 + +## 解释 +真实世界例子 + +> 当在长毛象的自然栖息地观察长毛象时，似乎它会根据情况来改变自己的行为。它开始可能很平静但是随着时间推移当它检测到威胁时它会对周围的环境感到愤怒和危险。 + +通俗的说 + +> 状态模式允许对象改变它的行为。 + +维基百科说 + +> 状态模式是一种允许对象在内部状态改变时改变它的行为的行为型设计模式。这种模式接近于有限状态机的概念。状态模式可以被理解为策略模式，它能够通过调用在模式接口中定义的方法来切换策略。 + +**编程示例** + +这里是模式接口和它具体的实现。 + +```java +public interface State { + + void onEnterState(); + + void observe(); +} + +public class PeacefulState implements State { + + private static final Logger LOGGER = LoggerFactory.getLogger(PeacefulState.class); + + private final Mammoth mammoth; + + public PeacefulState(Mammoth mammoth) { + this.mammoth = mammoth; + } + + @Override + public void observe() { + LOGGER.info("{} is calm and peaceful.", mammoth); + } + + @Override + public void onEnterState() { + LOGGER.info("{} calms down.", mammoth); + } +} + +public class AngryState implements State { + + private static final Logger LOGGER = LoggerFactory.getLogger(AngryState.class); + + private final Mammoth mammoth; + + public AngryState(Mammoth mammoth) { + this.mammoth = mammoth; + } + + @Override + public void observe() { + LOGGER.info("{} is furious!", mammoth); + } + + @Override + public void onEnterState() { + LOGGER.info("{} gets angry!", mammoth); + } +} +``` + +然后这里是包含状态的长毛象。 + +```java +public class Mammoth { + + private State state; + + public Mammoth() { + state = new PeacefulState(this); + } + + public void timePasses() { + if (state.getClass().equals(PeacefulState.class)) { + changeStateTo(new AngryState(this)); + } else { + changeStateTo(new PeacefulState(this)); + } + } + + private void changeStateTo(State newState) { + this.state = newState; + this.state.onEnterState(); + } + + @Override + public String toString() { + return "The mammoth"; + } + + public void observe() { + this.state.observe(); + } +} +``` + +然后这里是长毛象随着时间的推移后的整个行为示例。 + +```java + var mammoth = new Mammoth(); + mammoth.observe(); + mammoth.timePasses(); + mammoth.observe(); + mammoth.timePasses(); + mammoth.observe(); + + // The mammoth gets angry! + // The mammoth is furious! + // The mammoth calms down. + // The mammoth is calm and peaceful. +``` + +## 类图 + + +## 适用性 + +在以下两种情况下，请使用State模式 + +* 对象的行为取决于它的状态，并且它必须在运行时根据状态更改其行为。 +* 根据对象状态的不同，操作有大量的条件语句。此状态通常由一个或多个枚举常量表示。通常，几个操作将包含此相同的条件结构。状态模式把条件语句的分支分别放入单独的类中。这样一来，你就可以将对象的状态视为独立的对象，该对象可以独立于其他对象而变化。 + +## Java中例子 + +* [javax.faces.lifecycle.Lifecycle#execute()](http://docs.oracle.com/javaee/7/api/javax/faces/lifecycle/Lifecycle.html#execute-javax.faces.context.FacesContext-) controlled by [FacesServlet](http://docs.oracle.com/javaee/7/api/javax/faces/webapp/FacesServlet.html), the behavior is dependent on current phase of lifecycle. +* [JDiameter - Diameter State Machine](https://github.com/npathai/jdiameter/blob/master/core/jdiameter/api/src/main/java/org/jdiameter/api/app/State.java) + +## 鸣谢 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) +* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7) diff --git a/zh/template-method/README.md b/zh/template-method/README.md new file mode 100644 index 000000000000..f848552c33c2 --- /dev/null +++ b/zh/template-method/README.md @@ -0,0 +1,145 @@ +--- +layout: pattern +title: Template method +folder: template-method +permalink: /patterns/template-method/ +categories: Behavioral +tags: + - Gang of Four +--- + +## 目的 +在一个操作中定义算法的骨架，将某些步骤推迟到子类。模板方法允许子类重新定义算法的某些步骤，而无需更改算法的结构。 + +## 解释 +真实世界例子 + +> 偷东西的一般步骤是相同的。 首先，选择目标，然后以某种方式使其迷惑，最后，你偷走了该物品。然而这些步骤有很多实现方式。 + +通俗的说 + +> 模板方法模式在父类中列出一般的步骤然后让具体的子类定义实现细节。 + +维基百科说 + +> 在面向对象的编程中，模板方法是Gamma等人确定的行为设计模式之一。在《设计模式》一书中。模板方法是父类中一个方法，通常是一个抽象父类，根据许多高级步骤定义了操作的骨架。这些步骤本身由与模板方法在同一类中的其他帮助程序方法实现。 + +**编程示例** + +让我们首先介绍模板方法类及其具体实现。 + +```java +public abstract class StealingMethod { + + private static final Logger LOGGER = LoggerFactory.getLogger(StealingMethod.class); + + protected abstract String pickTarget(); + + protected abstract void confuseTarget(String target); + + protected abstract void stealTheItem(String target); + + public void steal() { + var target = pickTarget(); + LOGGER.info("The target has been chosen as {}.", target); + confuseTarget(target); + stealTheItem(target); + } +} + +public class SubtleMethod extends StealingMethod { + + private static final Logger LOGGER = LoggerFactory.getLogger(SubtleMethod.class); + + @Override + protected String pickTarget() { + return "shop keeper"; + } + + @Override + protected void confuseTarget(String target) { + LOGGER.info("Approach the {} with tears running and hug him!", target); + } + + @Override + protected void stealTheItem(String target) { + LOGGER.info("While in close contact grab the {}'s wallet.", target); + } +} + +public class HitAndRunMethod extends StealingMethod { + + private static final Logger LOGGER = LoggerFactory.getLogger(HitAndRunMethod.class); + + @Override + protected String pickTarget() { + return "old goblin woman"; + } + + @Override + protected void confuseTarget(String target) { + LOGGER.info("Approach the {} from behind.", target); + } + + @Override + protected void stealTheItem(String target) { + LOGGER.info("Grab the handbag and run away fast!"); + } +} +``` + +这是包含模板方法的半身贼类。 + +```java +public class HalflingThief { + + private StealingMethod method; + + public HalflingThief(StealingMethod method) { + this.method = method; + } + + public void steal() { + method.steal(); + } + + public void changeMethod(StealingMethod method) { + this.method = method; + } +} +``` +最后，我们展示半身人贼如何利用不同的偷窃方法。 + +```java + var thief = new HalflingThief(new HitAndRunMethod()); + thief.steal(); + thief.changeMethod(new SubtleMethod()); + thief.steal(); +``` + +## 类图 + + +## 适用性 + +使用模板方法模式可以 + +* 一次性实现一个算法中不变的部分并将其留给子类来实现可能变化的行为。 +* 子类之间的共同行为应分解并集中在一个共同类中，以避免代码重复。如Opdyke和Johnson所描述的，这是“重构概括”的一个很好的例子。你首先要确定现有代码中的差异，然后将差异拆分为新的操作。最后，将不同的代码替换为调用这些新操作之一的模板方法。 +* 控制子类扩展。您可以定义一个模板方法，该方法在特定点调用“ 钩子”操作，从而仅允许在这些点进行扩展 + +## 教程 + +* [Template-method Pattern Tutorial](https://www.journaldev.com/1763/template-method-design-pattern-in-java) + +## Java例子 + +* [javax.servlet.GenericServlet.init](https://jakarta.ee/specifications/servlet/4.0/apidocs/javax/servlet/GenericServlet.html#init--): +Method `GenericServlet.init(ServletConfig config)` calls the parameterless method `GenericServlet.init()` which is intended to be overridden in subclasses. +Method `GenericServlet.init(ServletConfig config)` is the template method in this example. + +## 鸣谢 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) +* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7)

train

train

HKTangShuo

train

iluwatar/java-design-patterns/1469_1631

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1469

iluwatar/java-design-patterns/1631

25ed2540f4b5d6fc2709c1e178082461a1da222d

18a1a725ee763dbf8f9c10025e23226f038cbb1c

Functional implementation of Strategy pattern

Strategy has been implemented using Java classes. In modern Java about the same can be achieved by passing methods. Let's amend the Strategy example with functional style implementation.

diff --git a/strategy/README.md b/strategy/README.md index b2330ceb84ce..2d2cbf9c4823 100644 --- a/strategy/README.md +++ b/strategy/README.md @@ -122,6 +122,51 @@ Program output: You cast the spell of disintegration and the dragon vaporizes in a pile of dust! ``` +What's more, the new feature Lambda Expressions in Java 8 provides another approach for the implementation: + +```java +public class LambdaStrategy { + + private static final Logger LOGGER = LoggerFactory.getLogger(LambdaStrategy.class); + + public enum Strategy implements DragonSlayingStrategy { + MeleeStrategy(() -> LOGGER.info( + "With your Excalibur you severe the dragon's head!")), + ProjectileStrategy(() -> LOGGER.info( + "You shoot the dragon with the magical crossbow and it falls dead on the ground!")), + SpellStrategy(() -> LOGGER.info( + "You cast the spell of disintegration and the dragon vaporizes in a pile of dust!")); + + private final DragonSlayingStrategy dragonSlayingStrategy; + + Strategy(DragonSlayingStrategy dragonSlayingStrategy) { + this.dragonSlayingStrategy = dragonSlayingStrategy; + } + + @Override + public void execute() { + dragonSlayingStrategy.execute(); + } + } +} +``` + +And here's the dragonslayer in action. + +```java + LOGGER.info("Green dragon spotted ahead!"); + dragonSlayer.changeStrategy(LambdaStrategy.Strategy.MeleeStrategy); + dragonSlayer.goToBattle(); + LOGGER.info("Red dragon emerges."); + dragonSlayer.changeStrategy(LambdaStrategy.Strategy.ProjectileStrategy); + dragonSlayer.goToBattle(); + LOGGER.info("Black dragon lands before you."); + dragonSlayer.changeStrategy(LambdaStrategy.Strategy.SpellStrategy); + dragonSlayer.goToBattle(); +``` + +Program output is the same as above one. + ## Class diagram  diff --git a/strategy/etc/strategy.urm.puml b/strategy/etc/strategy.urm.puml index 8b9daabb9db4..d9b9aa526d9a 100644 --- a/strategy/etc/strategy.urm.puml +++ b/strategy/etc/strategy.urm.puml @@ -14,6 +14,19 @@ package com.iluwatar.strategy { interface DragonSlayingStrategy { + execute() {abstract} } + class LambdaStrategy { + - LOGGER : Logger {static} + + LambdaStrategy() + } + enum Strategy { + + MeleeStrategy {static} + + ProjectileStrategy {static} + + SpellStrategy {static} + - dragonSlayingStrategy : DragonSlayingStrategy + + execute() + + valueOf(name : String) : Strategy {static} + + values() : Strategy[] {static} + } class MeleeStrategy { - LOGGER : Logger {static} + MeleeStrategy() @@ -30,7 +43,10 @@ package com.iluwatar.strategy { + execute() } } +Strategy ..+ LambdaStrategy +Strategy --> "-dragonSlayingStrategy" DragonSlayingStrategy DragonSlayer --> "-strategy" DragonSlayingStrategy +Strategy ..|> DragonSlayingStrategy MeleeStrategy ..|> DragonSlayingStrategy ProjectileStrategy ..|> DragonSlayingStrategy SpellStrategy ..|> DragonSlayingStrategy diff --git a/strategy/src/main/java/com/iluwatar/strategy/App.java b/strategy/src/main/java/com/iluwatar/strategy/App.java index c526c791787d..6313087b0bff 100644 --- a/strategy/src/main/java/com/iluwatar/strategy/App.java +++ b/strategy/src/main/java/com/iluwatar/strategy/App.java @@ -45,7 +45,7 @@ public class App { /** * Program entry point. - * + * * @param args command line args */ public static void main(String[] args) { @@ -60,7 +60,7 @@ public static void main(String[] args) { dragonSlayer.changeStrategy(new SpellStrategy()); dragonSlayer.goToBattle(); - // Java 8 Strategy pattern + // Java 8 functional implementation Strategy pattern LOGGER.info("Green dragon spotted ahead!"); dragonSlayer = new DragonSlayer( () -> LOGGER.info("With your Excalibur you severe the dragon's head!")); @@ -73,5 +73,16 @@ public static void main(String[] args) { dragonSlayer.changeStrategy(() -> LOGGER.info( "You cast the spell of disintegration and the dragon vaporizes in a pile of dust!")); dragonSlayer.goToBattle(); + + // Java 8 lambda implementation with enum Strategy pattern + LOGGER.info("Green dragon spotted ahead!"); + dragonSlayer.changeStrategy(LambdaStrategy.Strategy.MeleeStrategy); + dragonSlayer.goToBattle(); + LOGGER.info("Red dragon emerges."); + dragonSlayer.changeStrategy(LambdaStrategy.Strategy.ProjectileStrategy); + dragonSlayer.goToBattle(); + LOGGER.info("Black dragon lands before you."); + dragonSlayer.changeStrategy(LambdaStrategy.Strategy.SpellStrategy); + dragonSlayer.goToBattle(); } } diff --git a/strategy/src/main/java/com/iluwatar/strategy/LambdaStrategy.java b/strategy/src/main/java/com/iluwatar/strategy/LambdaStrategy.java new file mode 100644 index 000000000000..d7480601738b --- /dev/null +++ b/strategy/src/main/java/com/iluwatar/strategy/LambdaStrategy.java @@ -0,0 +1,29 @@ +package com.iluwatar.strategy; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class LambdaStrategy { + + private static final Logger LOGGER = LoggerFactory.getLogger(LambdaStrategy.class); + + public enum Strategy implements DragonSlayingStrategy { + MeleeStrategy(() -> LOGGER.info( + "With your Excalibur you severe the dragon's head!")), + ProjectileStrategy(() -> LOGGER.info( + "You shoot the dragon with the magical crossbow and it falls dead on the ground!")), + SpellStrategy(() -> LOGGER.info( + "You cast the spell of disintegration and the dragon vaporizes in a pile of dust!")); + + private final DragonSlayingStrategy dragonSlayingStrategy; + + Strategy(DragonSlayingStrategy dragonSlayingStrategy) { + this.dragonSlayingStrategy = dragonSlayingStrategy; + } + + @Override + public void execute() { + dragonSlayingStrategy.execute(); + } + } +}

train

train

iluwatar

train

iluwatar/java-design-patterns/1638_1650

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1638

iluwatar/java-design-patterns/1650

03bc4a6b9a6d43f20b14fa90758b848c6f4a08c5

846d05672a66e4464ebca61c56d061eb964df4c6

Parameter Object idiom

It's a simple workaround for Java not having default parameters: http://dolszewski.com/java/java-default-parameters/

diff --git a/parameter-object/README.md b/parameter-object/README.md new file mode 100644 index 000000000000..9783879f1472 --- /dev/null +++ b/parameter-object/README.md @@ -0,0 +1,138 @@ +--- +layout: pattern +title: Parameter Object +folder: parameter-object +permalink: /patterns/parameter-object/ +categories: Behavioral +tags: + - Extensibility +--- + +## Intent + +The syntax of Java language doesn’t allow you to declare a method with a predefined value +for a parameter. Probably the best option to achieve default method parameters in Java is +by using the method overloading. Method overloading allows you to declare several methods +with the same name but with a different number of parameters. But the main problem with +method overloading as a solution for default parameter values reveals itself when a method +accepts multiple parameters. Creating an overloaded method for each possible combination of +parameters might be cumbersome. To deal with this issue, the Parameter Object pattern is used. + +## Explanation + +The Parameter Object is simply a wrapper object for all parameters of a method. +It is nothing more than just a regular POJO. The advantage of the Parameter Object over a +regular method parameter list is the fact that class fields can have default values. +Once the wrapper class is created for the method parameter list, a corresponding builder class +is also created. Usually it's an inner static class. The final step is to use the builder +to construct a new parameter object. For those parameters that are skipped, +their default values are going to be used. + + +**Programmatic Example** + +Here's the simple `SearchService` class where Method Overloading is used to default values here. To use method overloading, either the number of arguments or argument type has to be different. + +```java +public class SearchService { + //Method Overloading example. SortOrder is defaulted in this method + public String search(String type, String sortBy) { + return getQuerySummary(type, sortBy, SortOrder.DESC); + } + + /* Method Overloading example. SortBy is defaulted in this method. Note that the type has to be + different here to overload the method */ + public String search(String type, SortOrder sortOrder) { + return getQuerySummary(type, "price", sortOrder); + } + + private String getQuerySummary(String type, String sortBy, SortOrder sortOrder) { + return "Requesting shoes of type \"" + type + "\" sorted by \"" + sortBy + "\" in \"" + + sortOrder.getValue() + "ending\" order..."; + } +} + +``` + +Next we present the `SearchService` with `ParameterObject` created with Builder pattern. + +```java +public class SearchService { + + /* Parameter Object example. Default values are abstracted into the Parameter Object + at the time of Object creation */ + public String search(ParameterObject parameterObject) { + return getQuerySummary(parameterObject.getType(), parameterObject.getSortBy(), + parameterObject.getSortOrder()); + } + + private String getQuerySummary(String type, String sortBy, SortOrder sortOrder) { + return "Requesting shoes of type \"" + type + "\" sorted by \"" + sortBy + "\" in \"" + + sortOrder.getValue() + "ending\" order..."; + } +} + +public class ParameterObject { + public static final String DEFAULT_SORT_BY = "price"; + public static final SortOrder DEFAULT_SORT_ORDER = SortOrder.ASC; + + private String type; + private String sortBy = DEFAULT_SORT_BY; + private SortOrder sortOrder = DEFAULT_SORT_ORDER; + + private ParameterObject(Builder builder) { + type = builder.type; + sortBy = builder.sortBy != null && !builder.sortBy.isBlank() ? builder.sortBy : sortBy; + sortOrder = builder.sortOrder != null ? builder.sortOrder : sortOrder; + } + + public static Builder newBuilder() { + return new Builder(); + } + + //Getters and Setters... + + public static final class Builder { + + private String type; + private String sortBy; + private SortOrder sortOrder; + + private Builder() { + } + + public Builder withType(String type) { + this.type = type; + return this; + } + + public Builder sortBy(String sortBy) { + this.sortBy = sortBy; + return this; + } + + public Builder sortOrder(SortOrder sortOrder) { + this.sortOrder = sortOrder; + return this; + } + + public ParameterObject build() { + return new ParameterObject(this); + } + } +} + + +``` + +## Class diagram + + + +## Applicability + +This pattern shows us the way to have default parameters for a method in Java as the language doesn't default parameters feature out of the box. + +## Credits + +- [Does Java have default parameters?](http://dolszewski.com/java/java-default-parameters) diff --git a/parameter-object/etc/parameter-object.urm.puml b/parameter-object/etc/parameter-object.urm.puml new file mode 100644 index 000000000000..6cdab214110c --- /dev/null +++ b/parameter-object/etc/parameter-object.urm.puml @@ -0,0 +1,52 @@ +@startuml +package com.iluwatar.parameter.object { + class App { + - LOGGER : Logger {static} + + App() + + main(args : String[]) {static} + } + class ParameterObject { + + DEFAULT_SORT_BY : String {static} + + DEFAULT_SORT_ORDER : SortOrder {static} + - sortBy : String + - sortOrder : SortOrder + - type : String + - ParameterObject(builder : Builder) + + getSortBy() : String + + getSortOrder() : SortOrder + + getType() : String + + newBuilder() : Builder {static} + + setSortBy(sortBy : String) + + setSortOrder(sortOrder : SortOrder) + + setType(type : String) + } + class Builder { + - sortBy : String + - sortOrder : SortOrder + - type : String + - Builder() + + build() : ParameterObject + + sortBy(sortBy : String) : Builder + + sortOrder(sortOrder : SortOrder) : Builder + + withType(type : String) : Builder + } + class SearchService { + + SearchService() + - getQuerySummary(type : String, sortBy : String, sortOrder : SortOrder) : String + + search(parameterObject : ParameterObject) : String + + search(type : String, sortBy : String) : String + + search(type : String, sortOrder : SortOrder) : String + } + enum SortOrder { + + ASC {static} + + DESC {static} + - value : String + + getValue() : String + + valueOf(name : String) : SortOrder {static} + + values() : SortOrder[] {static} + } +} +Builder --> "-sortOrder" SortOrder +Builder ..+ ParameterObject +ParameterObject --> "-DEFAULT_SORT_ORDER" SortOrder +@enduml diff --git a/parameter-object/pom.xml b/parameter-object/pom.xml new file mode 100644 index 000000000000..be64d62df81a --- /dev/null +++ b/parameter-object/pom.xml @@ -0,0 +1,61 @@ +<?xml version="1.0"?> +<!-- + + The MIT License + Copyright © 2014-2019 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.24.0-SNAPSHOT</version> + </parent> + <artifactId>parameter-object</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.parameter.object.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java new file mode 100644 index 000000000000..7d4f600e21fa --- /dev/null +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java @@ -0,0 +1,62 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * The syntax of Java language doesn’t allow you to declare a method with a predefined value + * for a parameter. Probably the best option to achieve default method parameters in Java is + * by using the method overloading. Method overloading allows you to declare several methods + * with the same name but with a different number of parameters. But the main problem with + * method overloading as a solution for default parameter values reveals itself when a method + * accepts multiple parameters. Creating an overloaded method for each possible combination of + * parameters might be cumbersome. To deal with this issue, the Parameter Object pattern is used. + * The Parameter Object is simply a wrapper object for all parameters of a method. + * It is nothing more than just a regular POJO. The advantage of the Parameter Object over a + * regular method parameter list is the fact that class fields can have default values. + * Once the wrapper class is created for the method parameter list, a corresponding builder class + * is also created. Usually it's an inner static class. The final step is to use the builder + * to construct a new parameter object. For those parameters that are skipped, + * their default values are going to be used. + */ +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + + /** + * Program entry point. + * + * @param args command line args + */ + public static void main(String[] args) { + ParameterObject params = ParameterObject.newBuilder() + .withType("sneakers") + .sortBy("brand") + .build(); + LOGGER.info(params.toString()); + LOGGER.info(new SearchService().search(params)); + } +} diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java new file mode 100644 index 000000000000..65f636191b5a --- /dev/null +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java @@ -0,0 +1,113 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +public class ParameterObject { + + /** + * Default values are defined here. + */ + public static final String DEFAULT_SORT_BY = "price"; + public static final SortOrder DEFAULT_SORT_ORDER = SortOrder.ASC; + + private String type; + + /** + * Default values are assigned here. + */ + private String sortBy = DEFAULT_SORT_BY; + private SortOrder sortOrder = DEFAULT_SORT_ORDER; + + /** + * Overriding default values on object creation only when builder object has a valid value. + */ + private ParameterObject(Builder builder) { + setType(builder.type); + setSortBy(builder.sortBy != null && !builder.sortBy.isBlank() ? builder.sortBy : sortBy); + setSortOrder(builder.sortOrder != null ? builder.sortOrder : sortOrder); + } + + public static Builder newBuilder() { + return new Builder(); + } + + public String getType() { + return type; + } + + public void setType(String type) { + this.type = type; + } + + public String getSortBy() { + return sortBy; + } + + public void setSortBy(String sortBy) { + this.sortBy = sortBy; + } + + public SortOrder getSortOrder() { + return sortOrder; + } + + public void setSortOrder(SortOrder sortOrder) { + this.sortOrder = sortOrder; + } + + @Override + public String toString() { + return String.format("ParameterObject[type='%s', sortBy='%s', sortOrder='%s']", + type, sortBy, sortOrder); + } + + public static final class Builder { + + private String type; + private String sortBy; + private SortOrder sortOrder; + + private Builder() { + } + + public Builder withType(String type) { + this.type = type; + return this; + } + + public Builder sortBy(String sortBy) { + this.sortBy = sortBy; + return this; + } + + public Builder sortOrder(SortOrder sortOrder) { + this.sortOrder = sortOrder; + return this; + } + + public ParameterObject build() { + return new ParameterObject(this); + } + } +} diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java new file mode 100644 index 000000000000..62acc840df92 --- /dev/null +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java @@ -0,0 +1,60 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +public class SearchService { + + /** + * Below two methods of name `search` is overloaded so that we can send a default value for + * one of the criteria and call the final api. A default SortOrder is sent in the first method + * and a default SortBy is sent in the second method. So two separate method definitions are + * needed for having default values for one argument in each case. Hence multiple overloaded + * methods are needed as the number of argument increases. + */ + public String search(String type, String sortBy) { + return getQuerySummary(type, sortBy, SortOrder.ASC); + } + + public String search(String type, SortOrder sortOrder) { + return getQuerySummary(type, "price", sortOrder); + } + + + /** + * The need for multiple method definitions can be avoided by the Parameter Object pattern. + * Below is the example where only one method is required and all the logic for having default + * values are abstracted into the Parameter Object at the time of object creation. + */ + public String search(ParameterObject parameterObject) { + return getQuerySummary(parameterObject.getType(), parameterObject.getSortBy(), + parameterObject.getSortOrder()); + } + + private String getQuerySummary(String type, String sortBy, SortOrder sortOrder) { + return String.format("Requesting shoes of type \"%s\" sorted by \"%s\" in \"%sending\" order..", + type, + sortBy, + sortOrder.getValue()); + } +} diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java new file mode 100644 index 000000000000..6420ca9e134f --- /dev/null +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java @@ -0,0 +1,39 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +public enum SortOrder { + ASC("asc"), + DESC("desc"); + + private String value; + + SortOrder(String value) { + this.value = value; + } + + public String getValue() { + return value; + } +} diff --git a/pom.xml b/pom.xml index c7d61a12bfab..48fa6fdcf801 100644 --- a/pom.xml +++ b/pom.xml @@ -208,6 +208,7 @@ <module>factory</module> <module>separated-interface</module> <module>special-case</module> + <module>parameter-object</module> </modules> <repositories>

diff --git a/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java b/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java new file mode 100644 index 000000000000..809e41f3677c --- /dev/null +++ b/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java @@ -0,0 +1,41 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +import org.junit.jupiter.api.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Application test + */ +class AppTest { + private static final Logger LOGGER = LoggerFactory.getLogger(AppTest.class); + + @Test + void shouldExecuteApplicationWithoutException() { + App.main(new String[]{}); + LOGGER.info("Executed successfully without exception."); + } +} diff --git a/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java b/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java new file mode 100644 index 000000000000..05907b9c677a --- /dev/null +++ b/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java @@ -0,0 +1,63 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +import org.junit.jupiter.api.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +class ParameterObjectTest { + + private static final Logger LOGGER = LoggerFactory.getLogger(ParameterObjectTest.class); + + @Test + public void testForDefaultSortBy() { + //Creating parameter object with default value for SortBy set + ParameterObject params = ParameterObject.newBuilder() + .withType("sneakers") + .sortOrder(SortOrder.DESC) + .build(); + + assertEquals(ParameterObject.DEFAULT_SORT_BY, params.getSortBy(), + "Default SortBy is not set."); + LOGGER.info("{} Default parameter value is set during object creation as no value is passed." + , "SortBy"); + } + + @Test + public void testForDefaultSortOrder() { + //Creating parameter object with default value for SortOrder set + ParameterObject params = ParameterObject.newBuilder() + .withType("sneakers") + .sortBy("brand") + .build(); + + assertEquals(ParameterObject.DEFAULT_SORT_ORDER, params.getSortOrder(), + "Default SortOrder is not set."); + LOGGER.info("{} Default parameter value is set during object creation as no value is passed." + , "SortOrder"); + } +} diff --git a/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java b/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java new file mode 100644 index 000000000000..d7633f0e3bf9 --- /dev/null +++ b/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java @@ -0,0 +1,63 @@ +/* + * The MIT License + * Copyright © 2014-2019 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.parameter.object; + +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +class SearchServiceTest { + private static final Logger LOGGER = LoggerFactory.getLogger(SearchServiceTest.class); + private ParameterObject parameterObject; + private SearchService searchService; + + @BeforeEach + public void setUp() { + //Creating parameter object with default values set + parameterObject = ParameterObject.newBuilder() + .withType("sneakers") + .build(); + + searchService = new SearchService(); + } + + /** + * Testing parameter object against the overloaded method to verify if the behaviour is same. + */ + @Test + public void testDefaultParametersMatch() { + assertEquals(searchService.search(parameterObject), searchService.search("sneakers", + SortOrder.ASC), "Default Parameter values do not not match."); + LOGGER.info("SortBy Default parameter value matches."); + + assertEquals(searchService.search(parameterObject), searchService.search("sneakers", + "price"), "Default Parameter values do not not match."); + LOGGER.info("SortOrder Default parameter value matches."); + + LOGGER.info("testDefaultParametersMatch executed successfully without errors."); + } +}

train

train

iluwatar

train

iluwatar/java-design-patterns/1663_1664

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1663

iluwatar/java-design-patterns/1664

0220f3df129e9b1c22f34bc48fc33ac57a009e37

c3c90e2bd451cdd60947704d1250c8b245881199

feature: Run sonar analysis on pull requests

⭐ This feature will help us review pull requests easier by helping us reviewing the modified or newly added code 👨🏻‍💻 by SonarCloud and comment out the report in the pull request. ✔️ This is going to help the contributor to increase their code quality and the coverage while removing static code errors. ✔️ Overall this is going to increase the code quality and make the process more smooth and fast. As we cannot run sonar analysis on pull requests from forked repositories using ❌ GitHub Actions; which we currently use due to its limitations to pass secrets, we will be moving with a solution from Circle CI for the time being to make our jobs easier.

diff --git a/.circleci/config.yml b/.circleci/config.yml new file mode 100644 index 000000000000..3e35aee712dd --- /dev/null +++ b/.circleci/config.yml @@ -0,0 +1,52 @@ +# +# The MIT License +# Copyright © 2014-2021 Ilkka Seppälä +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# + +version: 2 + +jobs: + sonar-pr: + docker: + - image: circleci/openjdk:11-node + steps: + - checkout + - restore_cache: + key: jdp-sonar-pr-{{ checksum "pom.xml" }} + - run: | + if [ -n "${CIRCLE_PR_NUMBER}" ]; then + MAVEN_OPTS="-Xmx3000m" xvfb-run ./mvnw -B clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \ + -Dsonar.pullrequest.key=${CIRCLE_PR_NUMBER} \ + -Dsonar.pullrequest.branch=${CIRCLE_BRANCH} \ + -Dsonar.pullrequest.base=master + else + echo "No Sonar PR analysis as this is not a pull request" + fi + - save_cache: + key: jdp-sonar-pr-{{ checksum "pom.xml" }} + paths: + - ~/.m2 + +workflows: + version: 2 + all: + jobs: + - sonar-pr diff --git a/.mvn/wrapper/MavenWrapperDownloader.java b/.mvn/wrapper/MavenWrapperDownloader.java index b901097f2db6..cfc696f0122a 100644 --- a/.mvn/wrapper/MavenWrapperDownloader.java +++ b/.mvn/wrapper/MavenWrapperDownloader.java @@ -1,18 +1,26 @@ /* - * Copyright 2007-present the original author or authors. + * The MIT License + * Copyright © 2014-2021 Ilkka Seppälä * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: * - * http://www.apache.org/licenses/LICENSE-2.0 + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. */ + import java.net.*; import java.io.*; import java.nio.channels.*; diff --git a/mvnw.cmd b/mvnw.cmd index 86115719e538..ed1dd59b0539 100644 --- a/mvnw.cmd +++ b/mvnw.cmd @@ -1,21 +1,25 @@ -@REM ---------------------------------------------------------------------------- -@REM Licensed to the Apache Software Foundation (ASF) under one -@REM or more contributor license agreements. See the NOTICE file -@REM distributed with this work for additional information -@REM regarding copyright ownership. The ASF licenses this file -@REM to you under the Apache License, Version 2.0 (the -@REM "License"); you may not use this file except in compliance -@REM with the License. You may obtain a copy of the License at @REM -@REM http://www.apache.org/licenses/LICENSE-2.0 +@REM The MIT License +@REM Copyright © 2014-2021 Ilkka Seppälä +@REM +@REM Permission is hereby granted, free of charge, to any person obtaining a copy +@REM of this software and associated documentation files (the "Software"), to deal +@REM in the Software without restriction, including without limitation the rights +@REM to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +@REM copies of the Software, and to permit persons to whom the Software is +@REM furnished to do so, subject to the following conditions: +@REM +@REM The above copyright notice and this permission notice shall be included in +@REM all copies or substantial portions of the Software. +@REM +@REM THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +@REM IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +@REM FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +@REM AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +@REM LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +@REM OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +@REM THE SOFTWARE. @REM -@REM Unless required by applicable law or agreed to in writing, -@REM software distributed under the License is distributed on an -@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY -@REM KIND, either express or implied. See the License for the -@REM specific language governing permissions and limitations -@REM under the License. -@REM ---------------------------------------------------------------------------- @REM ---------------------------------------------------------------------------- @REM Maven Start Up Batch script diff --git a/parameter-object/pom.xml b/parameter-object/pom.xml index be64d62df81a..5fbf060662c2 100644 --- a/parameter-object/pom.xml +++ b/parameter-object/pom.xml @@ -2,7 +2,7 @@ <!-- The MIT License - Copyright © 2014-2019 Ilkka Seppälä + Copyright © 2014-2021 Ilkka Seppälä Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java index 7d4f600e21fa..e0f2008d9b0e 100644 --- a/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/App.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java index 65f636191b5a..d90344930a54 100644 --- a/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java index 62acc840df92..7f038bbce13e 100644 --- a/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal diff --git a/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java b/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java index 6420ca9e134f..3f7240f6a4ba 100644 --- a/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java +++ b/parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal

diff --git a/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java b/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java index 809e41f3677c..16baef96fba6 100644 --- a/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java +++ b/parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal diff --git a/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java b/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java index 05907b9c677a..999cd19e0b2e 100644 --- a/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java +++ b/parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal diff --git a/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java b/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java index d7633f0e3bf9..76f56121335c 100644 --- a/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java +++ b/parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java @@ -1,6 +1,6 @@ /* * The MIT License - * Copyright © 2014-2019 Ilkka Seppälä + * Copyright © 2014-2021 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal

val

train

ohbus

train

iluwatar/java-design-patterns/1319_1742

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1319

iluwatar/java-design-patterns/1742

122e6edb38a3a1335363447a8a3f638826a6dab6

e498c25675856e00a8c122be5e01bf390f748a72

Table Module pattern

https://inviqa.com/blog/architecture-patterns-domain-model-and-friends

diff --git a/pom.xml b/pom.xml index 1b8f30e92b83..8173972bd27a 100644 --- a/pom.xml +++ b/pom.xml @@ -225,6 +225,7 @@ <module>active-object</module> <module>model-view-viewmodel</module> <module>composite-entity</module> + <module>table-module</module> <module>presentation</module> <module>lockable-object</module> </modules> diff --git a/table-module/README.md b/table-module/README.md new file mode 100644 index 000000000000..318a2694da26 --- /dev/null +++ b/table-module/README.md @@ -0,0 +1,134 @@ +--- +layout: pattern +title: Table Module +folder: table-module +permalink: /patterns/table-module/ +categories: Structural +tags: + - Data access +--- +## Intent +Table Module organizes domain logic with one class per table in the database, and a single instance of a class contains the various procedures that will act on the data. + +## Explanation + +Real world example + +> When dealing with a user system, we need some operations on the user table. We can use the table module pattern in this scenario. We can create a class named UserTableModule and initialize a instance of that class to handle the business logic for all rows in the user table. + +In plain words + +> A single instance that handles the business logic for all rows in a database table or view. + +Programmatic Example + +In the example of the user system, we need to deal with the domain logic of user login and user registration. We can use the table module pattern and create an instance of the class `UserTableModule` to handle the business logic for all rows in the user table. + +Here is the basic `User` entity. + +```java +@Setter +@Getter +@ToString +@EqualsAndHashCode +@AllArgsConstructor +public class User { + private int id; + private String username; + private String password; +} +``` + +Here is the `UserTableModule` class. + +```java +public class UserTableModule { + private final DataSource dataSource; + private Connection connection = null; + private ResultSet resultSet = null; + private PreparedStatement preparedStatement = null; + + public UserTableModule(final DataSource userDataSource) { + this.dataSource = userDataSource; + } + + /** + * Login using username and password. + * + * @param username the username of a user + * @param password the password of a user + * @return the execution result of the method + * @throws SQLException if any error + */ + public int login(final String username, final String password) throws SQLException { + // Method implementation. + + } + + /** + * Register a new user. + * + * @param user a user instance + * @return the execution result of the method + * @throws SQLException if any error + */ + public int registerUser(final User user) throws SQLException { + // Method implementation. + } +} +``` + +In the class `App`, we use an instance of the `UserTableModule` to handle user login and registration. + +```java +// Create data source and create the user table. +final var dataSource = createDataSource(); +createSchema(dataSource); +userTableModule = new UserTableModule(dataSource); + +//Initialize two users. +var user1 = new User(1, "123456", "123456"); +var user2 = new User(2, "test", "password"); + +//Login and register using the instance of userTableModule. +userTableModule.registerUser(user1); +userTableModule.login(user1.getUsername(), user1.getPassword()); +userTableModule.login(user2.getUsername(), user2.getPassword()); +userTableModule.registerUser(user2); +userTableModule.login(user2.getUsername(), user2.getPassword()); + +deleteSchema(dataSource); +``` + +The program output: + +```java +12:22:13.095 [main] INFO com.iluwatar.tablemodule.UserTableModule - Register successfully! +12:22:13.117 [main] INFO com.iluwatar.tablemodule.UserTableModule - Login successfully! +12:22:13.128 [main] INFO com.iluwatar.tablemodule.UserTableModule - Fail to login! +12:22:13.136 [main] INFO com.iluwatar.tablemodule.UserTableModule - Register successfully! +12:22:13.144 [main] INFO com.iluwatar.tablemodule.UserTableModule - Login successfully! +``` + +## Class diagram + + + +## Applicability + +Use the Table Module Pattern when + +- Domain logic is simple and data is in tabular form. +- The application only uses a few shared common table-oriented data structures. + +## Related patterns + +- [Transaction Script](https://java-design-patterns.com/patterns/transaction-script/) + +- Domain Model + +## Credits + +* [Table Module Pattern](http://wiki3.cosc.canterbury.ac.nz/index.php/Table_module_pattern) +* [Patterns of Enterprise Application Architecture](https://www.amazon.com/gp/product/0321127420/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=0321127420&linkId=18acc13ba60d66690009505577c45c04) +* [Architecture patterns: domain model and friends](https://inviqa.com/blog/architecture-patterns-domain-model-and-friends) \ No newline at end of file diff --git a/table-module/etc/table-module.urm.puml b/table-module/etc/table-module.urm.puml new file mode 100644 index 000000000000..6cf75797f080 --- /dev/null +++ b/table-module/etc/table-module.urm.puml @@ -0,0 +1,38 @@ +@startuml +package com.iluwatar.tablemodule { + class App { + - DB_URL : String {static} + - LOGGER : Logger {static} + - App() + - createDataSource() : DataSource {static} + - createSchema(dataSource : DataSource) {static} + - deleteSchema(dataSource : DataSource) {static} + + main(args : String[]) {static} + } + class User { + - id : int + - password : String + - username : String + + User(id : int, username : String, password : String) + # canEqual(other : Object) : boolean + + equals(o : Object) : boolean + + getId() : int + + getPassword() : String + + getUsername() : String + + hashCode() : int + + setId(id : int) + + setPassword(password : String) + + setUsername(username : String) + + toString() : String + } + class UserTableModule { + + CREATE_SCHEMA_SQL : String {static} + + DELETE_SCHEMA_SQL : String {static} + - LOGGER : Logger {static} + - dataSource : DataSource + + UserTableModule(userDataSource : DataSource) + + login(username : String, password : String) : int + + registerUser(user : User) : int + } +} +@enduml \ No newline at end of file diff --git a/table-module/pom.xml b/table-module/pom.xml new file mode 100644 index 000000000000..eae698c0909e --- /dev/null +++ b/table-module/pom.xml @@ -0,0 +1,73 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + The MIT License + Copyright © 2014-2021 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xmlns="http://maven.apache.org/POM/4.0.0" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <parent> + <artifactId>java-design-patterns</artifactId> + <groupId>com.iluwatar</groupId> + <version>1.25.0-SNAPSHOT</version> + </parent> + <modelVersion>4.0.0</modelVersion> + + <artifactId>table-module</artifactId> + + <dependencies> + <dependency> + <groupId>com.h2database</groupId> + <artifactId>h2</artifactId> + </dependency> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.mockito</groupId> + <artifactId>mockito-core</artifactId> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.tablemodule.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> + +</project> diff --git a/table-module/src/main/java/com/iluwatar/tablemodule/App.java b/table-module/src/main/java/com/iluwatar/tablemodule/App.java new file mode 100644 index 000000000000..7b22666e08eb --- /dev/null +++ b/table-module/src/main/java/com/iluwatar/tablemodule/App.java @@ -0,0 +1,81 @@ +package com.iluwatar.tablemodule; + +import java.sql.SQLException; +import javax.sql.DataSource; + +import lombok.extern.slf4j.Slf4j; +import org.h2.jdbcx.JdbcDataSource; + + +/** + * Table Module pattern is a domain logic pattern. + * In Table Module a single class encapsulates all the domain logic for all + * records stored in a table or view. It's important to note that there is no + * translation of data between objects and rows, as it happens in Domain Model, + * hence implementation is relatively simple when compared to the Domain + * Model pattern. + * + * <p>In this example we will use the Table Module pattern to implement register + * and login methods for the records stored in the user table. The main + * method will initialise an instance of {@link UserTableModule} and use it to + * handle the domain logic for the user table.</p> + */ +@Slf4j +public final class App { + private static final String DB_URL = "jdbc:h2:~/test"; + + /** + * Private constructor. + */ + private App() { + + } + + /** + * Program entry point. + * + * @param args command line args. + * @throws SQLException if any error occurs. + */ + public static void main(final String[] args) throws SQLException { + // Create data source and create the user table. + final var dataSource = createDataSource(); + createSchema(dataSource); + var userTableModule = new UserTableModule(dataSource); + + // Initialize two users. + var user1 = new User(1, "123456", "123456"); + var user2 = new User(2, "test", "password"); + + // Login and register using the instance of userTableModule. + userTableModule.registerUser(user1); + userTableModule.login(user1.getUsername(), user1.getPassword()); + userTableModule.login(user2.getUsername(), user2.getPassword()); + userTableModule.registerUser(user2); + userTableModule.login(user2.getUsername(), user2.getPassword()); + + deleteSchema(dataSource); + } + + private static void deleteSchema(final DataSource dataSource) + throws SQLException { + try (var connection = dataSource.getConnection(); + var statement = connection.createStatement()) { + statement.execute(UserTableModule.DELETE_SCHEMA_SQL); + } + } + + private static void createSchema(final DataSource dataSource) + throws SQLException { + try (var connection = dataSource.getConnection(); + var statement = connection.createStatement()) { + statement.execute(UserTableModule.CREATE_SCHEMA_SQL); + } + } + + private static DataSource createDataSource() { + var dataSource = new JdbcDataSource(); + dataSource.setURL(DB_URL); + return dataSource; + } +} diff --git a/table-module/src/main/java/com/iluwatar/tablemodule/User.java b/table-module/src/main/java/com/iluwatar/tablemodule/User.java new file mode 100644 index 000000000000..ac307d4503b3 --- /dev/null +++ b/table-module/src/main/java/com/iluwatar/tablemodule/User.java @@ -0,0 +1,23 @@ +package com.iluwatar.tablemodule; + +import lombok.AllArgsConstructor; +import lombok.EqualsAndHashCode; +import lombok.Getter; +import lombok.Setter; +import lombok.ToString; + + +/** + * A user POJO that represents the data that will be read from the data source. + */ +@Setter +@Getter +@ToString +@EqualsAndHashCode +@AllArgsConstructor +public class User { + private int id; + private String username; + private String password; + +} diff --git a/table-module/src/main/java/com/iluwatar/tablemodule/UserTableModule.java b/table-module/src/main/java/com/iluwatar/tablemodule/UserTableModule.java new file mode 100644 index 000000000000..f1a4d044454d --- /dev/null +++ b/table-module/src/main/java/com/iluwatar/tablemodule/UserTableModule.java @@ -0,0 +1,96 @@ +package com.iluwatar.tablemodule; + +import java.sql.ResultSet; +import java.sql.SQLException; +import javax.sql.DataSource; + +import lombok.extern.slf4j.Slf4j; + + +/** + * This class organizes domain logic with the user table in the + * database. A single instance of this class contains the various + * procedures that will act on the data. + */ +@Slf4j +public class UserTableModule { + /** + * Public element for creating schema. + */ + public static final String CREATE_SCHEMA_SQL = + "CREATE TABLE IF NOT EXISTS USERS (ID NUMBER, USERNAME VARCHAR(30) " + + "UNIQUE,PASSWORD VARCHAR(30))"; + /** + * Public element for deleting schema. + */ + public static final String DELETE_SCHEMA_SQL = "DROP TABLE USERS IF EXISTS"; + private final DataSource dataSource; + + + /** + * Public constructor. + * + * @param userDataSource the data source in the database + */ + public UserTableModule(final DataSource userDataSource) { + this.dataSource = userDataSource; + } + + + /** + * Login using username and password. + * + * @param username the username of a user + * @param password the password of a user + * @return the execution result of the method + * @throws SQLException if any error + */ + public int login(final String username, final String password) + throws SQLException { + var sql = "select count(*) from USERS where username=? and password=?"; + ResultSet resultSet = null; + try (var connection = dataSource.getConnection(); + var preparedStatement = + connection.prepareStatement(sql) + ) { + var result = 0; + preparedStatement.setString(1, username); + preparedStatement.setString(2, password); + resultSet = preparedStatement.executeQuery(); + while (resultSet.next()) { + result = resultSet.getInt(1); + } + if (result == 1) { + LOGGER.info("Login successfully!"); + } else { + LOGGER.info("Fail to login!"); + } + return result; + } finally { + if (resultSet != null) { + resultSet.close(); + } + } + } + + /** + * Register a new user. + * + * @param user a user instance + * @return the execution result of the method + * @throws SQLException if any error + */ + public int registerUser(final User user) throws SQLException { + var sql = "insert into USERS (username, password) values (?,?)"; + try (var connection = dataSource.getConnection(); + var preparedStatement = + connection.prepareStatement(sql) + ) { + preparedStatement.setString(1, user.getUsername()); + preparedStatement.setString(2, user.getPassword()); + var result = preparedStatement.executeUpdate(); + LOGGER.info("Register successfully!"); + return result; + } + } +}

diff --git a/table-module/src/test/java/com/iluwatar/tablemodule/AppTest.java b/table-module/src/test/java/com/iluwatar/tablemodule/AppTest.java new file mode 100644 index 000000000000..cafae7cdbe38 --- /dev/null +++ b/table-module/src/test/java/com/iluwatar/tablemodule/AppTest.java @@ -0,0 +1,16 @@ +package com.iluwatar.tablemodule; + +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +/** + * Tests that the table module example runs without errors. + */ +class AppTest { + + @Test + void shouldExecuteWithoutException() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} diff --git a/table-module/src/test/java/com/iluwatar/tablemodule/UserTableModuleTest.java b/table-module/src/test/java/com/iluwatar/tablemodule/UserTableModuleTest.java new file mode 100644 index 000000000000..86685f58dd9c --- /dev/null +++ b/table-module/src/test/java/com/iluwatar/tablemodule/UserTableModuleTest.java @@ -0,0 +1,78 @@ +package com.iluwatar.tablemodule; + +import org.h2.jdbcx.JdbcDataSource; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +import javax.sql.DataSource; +import java.sql.DriverManager; +import java.sql.SQLException; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertThrows; + +class UserTableModuleTest { + private static final String DB_URL = "jdbc:h2:~/test"; + + private static DataSource createDataSource() { + var dataSource = new JdbcDataSource(); + dataSource.setURL(DB_URL); + return dataSource; + } + + @BeforeEach + void setUp() throws SQLException { + try (var connection = DriverManager.getConnection(DB_URL); + var statement = connection.createStatement()) { + statement.execute(UserTableModule.DELETE_SCHEMA_SQL); + statement.execute(UserTableModule.CREATE_SCHEMA_SQL); + } + } + + @AfterEach + void tearDown() throws SQLException { + try (var connection = DriverManager.getConnection(DB_URL); + var statement = connection.createStatement()) { + statement.execute(UserTableModule.DELETE_SCHEMA_SQL); + } + } + + @Test + void loginShouldFail() throws SQLException { + var dataSource = createDataSource(); + var userTableModule = new UserTableModule(dataSource); + var user = new User(1, "123456", "123456"); + assertEquals(0, userTableModule.login(user.getUsername(), + user.getPassword())); + } + + @Test + void loginShouldSucceed() throws SQLException { + var dataSource = createDataSource(); + var userTableModule = new UserTableModule(dataSource); + var user = new User(1, "123456", "123456"); + userTableModule.registerUser(user); + assertEquals(1, userTableModule.login(user.getUsername(), + user.getPassword())); + } + + @Test + void registerShouldFail() throws SQLException { + var dataSource = createDataSource(); + var userTableModule = new UserTableModule(dataSource); + var user = new User(1, "123456", "123456"); + userTableModule.registerUser(user); + assertThrows(SQLException.class, () -> { + userTableModule.registerUser(user); + }); + } + + @Test + void registerShouldSucceed() throws SQLException { + var dataSource = createDataSource(); + var userTableModule = new UserTableModule(dataSource); + var user = new User(1, "123456", "123456"); + assertEquals(1, userTableModule.registerUser(user)); + } +} \ No newline at end of file diff --git a/table-module/src/test/java/com/iluwatar/tablemodule/UserTest.java b/table-module/src/test/java/com/iluwatar/tablemodule/UserTest.java new file mode 100644 index 000000000000..669d86035f01 --- /dev/null +++ b/table-module/src/test/java/com/iluwatar/tablemodule/UserTest.java @@ -0,0 +1,131 @@ +package com.iluwatar.tablemodule; + +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.*; + +class UserTest { + @Test + void testCanEqual() { + assertFalse((new User(1, "janedoe", "iloveyou")) + .canEqual("Other")); + } + + @Test + void testCanEqual2() { + var user = new User(1, "janedoe", "iloveyou"); + assertTrue(user.canEqual(new User(1, "janedoe", + "iloveyou"))); + } + + @Test + void testEquals1() { + var user = new User(1, "janedoe", "iloveyou"); + assertNotEquals("42", user); + } + + @Test + void testEquals2() { + var user = new User(1, "janedoe", "iloveyou"); + assertEquals(user, new User(1, "janedoe", + "iloveyou")); + } + + @Test + void testEquals3() { + var user = new User(123, "janedoe", "iloveyou"); + assertNotEquals(user, new User(1, "janedoe", + "iloveyou")); + } + + @Test + void testEquals4() { + var user = new User(1, null, "iloveyou"); + assertNotEquals(user, new User(1, "janedoe", + "iloveyou")); + } + + @Test + void testEquals5() { + var user = new User(1, "iloveyou", "iloveyou"); + assertNotEquals(user, new User(1, "janedoe", + "iloveyou")); + } + + @Test + void testEquals6() { + var user = new User(1, "janedoe", "janedoe"); + assertNotEquals(user, new User(1, "janedoe", + "iloveyou")); + } + + @Test + void testEquals7() { + var user = new User(1, "janedoe", null); + assertNotEquals(user, new User(1, "janedoe", + "iloveyou")); + } + + @Test + void testEquals8() { + var user = new User(1, null, "iloveyou"); + assertEquals(user, new User(1, null, + "iloveyou")); + } + + @Test + void testEquals9() { + var user = new User(1, "janedoe", null); + assertEquals(user, new User(1, "janedoe", + null)); + } + + @Test + void testHashCode1() { + assertEquals(-1758941372, (new User(1, "janedoe", + "iloveyou")).hashCode()); + + } + + @Test + void testHashCode2() { + assertEquals(-1332207447, (new User(1, null, + "iloveyou")).hashCode()); + } + + @Test + void testHashCode3() { + assertEquals(-426522485, (new User(1, "janedoe", + null)).hashCode()); + } + + @Test + void testSetId() { + var user = new User(1, "janedoe", "iloveyou"); + user.setId(2); + assertEquals(2, user.getId()); + } + + @Test + void testSetPassword() { + var user = new User(1, "janedoe", "tmp"); + user.setPassword("iloveyou"); + assertEquals("iloveyou", user.getPassword()); + } + + @Test + void testSetUsername() { + var user = new User(1, "tmp", "iloveyou"); + user.setUsername("janedoe"); + assertEquals("janedoe", user.getUsername()); + } + + @Test + void testToString() { + var user = new User(1, "janedoe", "iloveyou"); + assertEquals(String.format("User(id=%s, username=%s, password=%s)", + user.getId(), user.getUsername(), user.getPassword()), + user.toString()); + } +} +

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iluwatar/java-design-patterns/1747_1748

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iluwatar/java-design-patterns/1748

1dd26289e5836ee31dca18b6077666f357322ca3

1388e38744b7b83ea4bfa473a719e764ef83534a

Issue with all contributors badge in Readme.md file

Observed that when we click on the `all contributors` badge on the project page , it does not re-direct us to the sections where all the project contributors are listed .  **Possible fix will be to correct the URL for this badge inside the projects Readme.md file .**

diff --git a/README.md b/README.md index 971fe9073997..8c520b741499 100644 --- a/README.md +++ b/README.md @@ -10,7 +10,7 @@ [](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns) [](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section --> -[](#contributors-) +[](#contributors) <!-- ALL-CONTRIBUTORS-BADGE:END --> <br/>

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42eb7950aef44e00b9a5363e681762a1bf1271c3

0ff4e16f0c5ed3960e08df16a6ebb67470bcaf28

Readme Update: Show Project Contributors automatically without adding them in successive commits

- Using dynamic web app [contributors-img](https://contrib.rocks/preview) - Reduces commits made for successive contributors - Takes less space in Readme file and increases the count automatically. **Example screenshot** 

diff --git a/README.md b/README.md index c7c137fa3d5c..a28380099c06 100644 --- a/README.md +++ b/README.md @@ -74,271 +74,10 @@ This project is licensed under the terms of the MIT license. <!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section --> <!-- prettier-ignore-start --> <!-- markdownlint-disable --> -<table> - <tr> - <td align="center"><a href="https://github.com/iluwatar"><img src="https://avatars1.githubusercontent.com/u/582346?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ilkka Seppälä</b>}</a><br /><a href="#projectManagement-iluwatar" title="Project Management">📆</a> <a href="#maintenance-iluwatar" title="Maintenance">🚧</a> <a href="#content-iluwatar" title="Content">🖋</a></td> - <td align="center"><a href="https://github.com/amit1307"><img src="https://avatars0.githubusercontent.com/u/23420222?v=4?s=100" width="100px;" alt=""/><br />_{<b>amit1307</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=amit1307" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/npathai"><img src="https://avatars2.githubusercontent.com/u/1792515?v=4?s=100" width="100px;" alt=""/><br />_{<b>Narendra Pathai</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=npathai" title="Code">💻</a> <a href="#ideas-npathai" title="Ideas, Planning, & Feedback">🤔</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Anpathai" title="Reviewed Pull Requests">👀</a></td> - <td align="center"><a href="https://github.com/fluxw42"><img src="https://avatars1.githubusercontent.com/u/1545460?v=4?s=100" width="100px;" alt=""/><br />_{<b>Jeroen Meulemeester</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=fluxw42" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="http://www.joemccarthy.co.uk"><img src="https://avatars0.githubusercontent.com/u/4526195?v=4?s=100" width="100px;" alt=""/><br />_{<b>Joseph McCarthy</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mikulucky" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/thomasoss"><img src="https://avatars1.githubusercontent.com/u/22516154?v=4?s=100" width="100px;" alt=""/><br />_{<b>Thomas</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=thomasoss" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/anuragagarwal561994"><img src="https://avatars1.githubusercontent.com/u/6075379?v=4?s=100" width="100px;" alt=""/><br />_{<b>Anurag Agarwal</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=anuragagarwal561994" title="Code">💻</a></td> - <td align="center"><a href="https://markusmo3.github.io"><img src="https://avatars1.githubusercontent.com/u/3317416?v=4?s=100" width="100px;" alt=""/><br />_{<b>Markus Moser</b>}</a><br /><a href="#design-markusmo3" title="Design">🎨</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=markusmo3" title="Code">💻</a> <a href="#ideas-markusmo3" title="Ideas, Planning, & Feedback">🤔</a></td> - </tr> - <tr> - <td align="center"><a href="https://twitter.com/i_sabiq"><img src="https://avatars1.githubusercontent.com/u/19510920?v=4?s=100" width="100px;" alt=""/><br />_{<b>Sabiq Ihab</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=isabiq" title="Code">💻</a></td> - <td align="center"><a href="http://inbravo.github.io"><img src="https://avatars3.githubusercontent.com/u/5253764?v=4?s=100" width="100px;" alt=""/><br />_{<b>Amit Dixit</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=inbravo" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/piyushchaudhari04"><img src="https://avatars3.githubusercontent.com/u/10268029?v=4?s=100" width="100px;" alt=""/><br />_{<b>Piyush Kailash Chaudhari</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=piyushchaudhari04" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/joshzambales"><img src="https://avatars1.githubusercontent.com/u/8704552?v=4?s=100" width="100px;" alt=""/><br />_{<b>joshzambales</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=joshzambales" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/Crossy147"><img src="https://avatars2.githubusercontent.com/u/7272996?v=4?s=100" width="100px;" alt=""/><br />_{<b>Kamil Pietruszka</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Crossy147" title="Code">💻</a></td> - <td align="center"><a href="http://cs.joensuu.fi/~zkhayda"><img src="https://avatars2.githubusercontent.com/u/660742?v=4?s=100" width="100px;" alt=""/><br />_{<b>Zafar Khaydarov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=zafarella" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=zafarella" title="Documentation">📖</a></td> - <td align="center"><a href="https://kemitix.github.io/"><img src="https://avatars1.githubusercontent.com/u/1147749?v=4?s=100" width="100px;" alt=""/><br />_{<b>Paul Campbell</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kemitix" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Argyro-Sioziou"><img src="https://avatars0.githubusercontent.com/u/22822639?v=4?s=100" width="100px;" alt=""/><br />_{<b>Argyro Sioziou</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Argyro-Sioziou" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/TylerMcConville"><img src="https://avatars0.githubusercontent.com/u/4946449?v=4?s=100" width="100px;" alt=""/><br />_{<b>TylerMcConville</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=TylerMcConville" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/saksham93"><img src="https://avatars1.githubusercontent.com/u/37399540?v=4?s=100" width="100px;" alt=""/><br />_{<b>saksham93</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=saksham93" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/nikhilbarar"><img src="https://avatars2.githubusercontent.com/u/37332144?v=4?s=100" width="100px;" alt=""/><br />_{<b>nikhilbarar</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=nikhilbarar" title="Code">💻</a></td> - <td align="center"><a href="http://colinbut.com"><img src="https://avatars2.githubusercontent.com/u/10725674?v=4?s=100" width="100px;" alt=""/><br />_{<b>Colin But</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=colinbut" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/ruslanpa"><img src="https://avatars2.githubusercontent.com/u/1503411?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ruslan</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ruslanpa" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/JuhoKang"><img src="https://avatars1.githubusercontent.com/u/4745294?v=4?s=100" width="100px;" alt=""/><br />_{<b>Juho Kang</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=JuhoKang" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/dheeraj-mummareddy"><img src="https://avatars2.githubusercontent.com/u/7002230?v=4?s=100" width="100px;" alt=""/><br />_{<b>Dheeraj Mummareddy</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dheeraj-mummareddy" title="Code">💻</a></td> - <td align="center"><a href="https://www.bernardosulzbach.com"><img src="https://avatars0.githubusercontent.com/u/8271090?v=4?s=100" width="100px;" alt=""/><br />_{<b>Bernardo Sulzbach</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=bernardosulzbach" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/4lexis"><img src="https://avatars0.githubusercontent.com/u/19871727?v=4?s=100" width="100px;" alt=""/><br />_{<b>Aleksandar Dudukovic</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=4lexis" title="Code">💻</a></td> - <td align="center"><a href="https://www.yusufaytas.com"><img src="https://avatars2.githubusercontent.com/u/1049483?v=4?s=100" width="100px;" alt=""/><br />_{<b>Yusuf Aytaş</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=yusufaytas" title="Code">💻</a></td> - <td align="center"><a href="http://futurehomes.hu"><img src="https://avatars2.githubusercontent.com/u/1001491?v=4?s=100" width="100px;" alt=""/><br />_{<b>Mihály Kuprivecz</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=qpi" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/kapinuss"><img src="https://avatars0.githubusercontent.com/u/17639945?v=4?s=100" width="100px;" alt=""/><br />_{<b>Stanislav Kapinus</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kapinuss" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/gvsharma"><img src="https://avatars1.githubusercontent.com/u/6648152?v=4?s=100" width="100px;" alt=""/><br />_{<b>GVSharma</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gvsharma" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/SrdjanPaunovic"><img src="https://avatars1.githubusercontent.com/u/22815104?v=4?s=100" width="100px;" alt=""/><br />_{<b>Srđan Paunović</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=SrdjanPaunovic" title="Code">💻</a></td> - <td align="center"><a href="https://sideris.xyz/"><img src="https://avatars3.githubusercontent.com/u/5484694?v=4?s=100" width="100px;" alt=""/><br />_{<b>Petros G. Sideris</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=sideris" title="Code">💻</a></td> - <td align="center"><a href="https://www.linkedin.com/in/pramodgupta3/"><img src="https://avatars1.githubusercontent.com/u/2184241?v=4?s=100" width="100px;" alt=""/><br />_{<b>Pramod Gupta</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3AIAmPramod" title="Reviewed Pull Requests">👀</a></td> - </tr> - <tr> - <td align="center"><a href="https://amarnath510.github.io/portfolio"><img src="https://avatars0.githubusercontent.com/u/4599623?v=4?s=100" width="100px;" alt=""/><br />_{<b>Amarnath Chandana</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Amarnath510" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Anurag870"><img src="https://avatars1.githubusercontent.com/u/6295975?v=4?s=100" width="100px;" alt=""/><br />_{<b>Anurag870</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Anurag870" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=Anurag870" title="Documentation">📖</a></td> - <td align="center"><a href="http://theerroris.me"><img src="https://avatars0.githubusercontent.com/u/1685953?v=4?s=100" width="100px;" alt=""/><br />_{<b>Wes Gilleland</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Deathnerd" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Harshrajsinh"><img src="https://avatars2.githubusercontent.com/u/22811531?v=4?s=100" width="100px;" alt=""/><br />_{<b>Harshraj Thakor</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Harshrajsinh" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/MaVdbussche"><img src="https://avatars1.githubusercontent.com/u/26136934?v=4?s=100" width="100px;" alt=""/><br />_{<b>Martin Vandenbussche</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=MaVdbussche" title="Code">💻</a></td> - <td align="center"><a href="https://alexsomai.com"><img src="https://avatars1.githubusercontent.com/u/5720977?v=4?s=100" width="100px;" alt=""/><br />_{<b>Alexandru Somai</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=alexsomai" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/amogozov"><img src="https://avatars3.githubusercontent.com/u/7372215?v=4?s=100" width="100px;" alt=""/><br />_{<b>Artur Mogozov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=amogozov" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/anthonycampbell"><img src="https://avatars3.githubusercontent.com/u/10249255?v=4?s=100" width="100px;" alt=""/><br />_{<b>anthony</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=anthonycampbell" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="http://ccygnus.com/"><img src="https://avatars1.githubusercontent.com/u/9342724?v=4?s=100" width="100px;" alt=""/><br />_{<b>Christian Cygnus</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=christophercolumbusdog" title="Code">💻</a></td> - <td align="center"><a href="https://about.me/dzmitryh"><img src="https://avatars2.githubusercontent.com/u/5390492?v=4?s=100" width="100px;" alt=""/><br />_{<b>Dima Gubin</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dzmitryh" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/jjjimenez100"><img src="https://avatars3.githubusercontent.com/u/22243493?v=4?s=100" width="100px;" alt=""/><br />_{<b>Joshua Jimenez</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=jjjimenez100" title="Code">💻</a></td> - <td align="center"><a href="http://about.me/kaiwinter"><img src="https://avatars0.githubusercontent.com/u/110982?v=4?s=100" width="100px;" alt=""/><br />_{<b>Kai Winter</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kaiwinter" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/lbroman"><img src="https://avatars1.githubusercontent.com/u/86007?v=4?s=100" width="100px;" alt=""/><br />_{<b>lbroman</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=lbroman" title="Code">💻</a></td> - <td align="center"><a href="https://przemeknowak.com"><img src="https://avatars1.githubusercontent.com/u/3254609?v=4?s=100" width="100px;" alt=""/><br />_{<b>Przemek</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=pnowy" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/prafful1"><img src="https://avatars0.githubusercontent.com/u/14350274?v=4?s=100" width="100px;" alt=""/><br />_{<b>Prafful Agarwal</b>}</a><br /><a href="#content-prafful1" title="Content">🖋</a></td> - <td align="center"><a href="https://github.com/sankypanhale"><img src="https://avatars1.githubusercontent.com/u/6478783?v=4?s=100" width="100px;" alt=""/><br />_{<b>Sanket Panhale</b>}</a><br /><a href="#content-sankypanhale" title="Content">🖋</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/staillebois"><img src="https://avatars0.githubusercontent.com/u/23701200?v=4?s=100" width="100px;" alt=""/><br />_{<b>staillebois</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=staillebois" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/valdar-hu"><img src="https://avatars3.githubusercontent.com/u/17962817?v=4?s=100" width="100px;" alt=""/><br />_{<b>Krisztián Nagy</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=valdar-hu" title="Code">💻</a></td> - <td align="center"><a href="https://www.vanogrid.com"><img src="https://avatars0.githubusercontent.com/u/4307918?v=4?s=100" width="100px;" alt=""/><br />_{<b>Alexander Ivanov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=vanogrid" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/yosfik"><img src="https://avatars3.githubusercontent.com/u/4850270?v=4?s=100" width="100px;" alt=""/><br />_{<b>Yosfik Alqadri</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=yosfik" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/7agustibm"><img src="https://avatars0.githubusercontent.com/u/8149332?v=4?s=100" width="100px;" alt=""/><br />_{<b>Agustí Becerra Milà</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=7agustibm" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Juaanma"><img src="https://avatars3.githubusercontent.com/u/7390500?v=4?s=100" width="100px;" alt=""/><br />_{<b>Juan Manuel Suárez</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Juaanma" title="Code">💻</a></td> - <td align="center"><a href="http://www.devsedge.net/"><img src="https://avatars0.githubusercontent.com/u/9956006?v=4?s=100" width="100px;" alt=""/><br />_{<b>Luigi Cortese</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=LuigiCortese" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Rzeposlaw"><img src="https://avatars2.githubusercontent.com/u/18425745?v=4?s=100" width="100px;" alt=""/><br />_{<b>Katarzyna Rzepecka</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Rzeposlaw" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="http://adamski.pro"><img src="https://avatars1.githubusercontent.com/u/6537430?v=4?s=100" width="100px;" alt=""/><br />_{<b>adamski.pro</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=akrystian" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/baislsl"><img src="https://avatars0.githubusercontent.com/u/17060584?v=4?s=100" width="100px;" alt=""/><br />_{<b>Shengli Bai</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=baislsl" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/besok"><img src="https://avatars2.githubusercontent.com/u/29834592?v=4?s=100" width="100px;" alt=""/><br />_<b>Boris</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=besok" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/dmitraver"><img src="https://avatars3.githubusercontent.com/u/1798156?v=4?s=100" width="100px;" alt=""/><br />_{<b>Dmitry Avershin</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dmitraver" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/fanofxiaofeng"><img src="https://avatars0.githubusercontent.com/u/3983683?v=4?s=100" width="100px;" alt=""/><br />_{<b>靳阳</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=fanofxiaofeng" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/hoangnam2261"><img src="https://avatars2.githubusercontent.com/u/31692990?v=4?s=100" width="100px;" alt=""/><br />_{<b>hoangnam2261</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hoangnam2261" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/jarpit96"><img src="https://avatars2.githubusercontent.com/u/10098713?v=4?s=100" width="100px;" alt=""/><br />_{<b>Arpit Jain</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=jarpit96" title="Code">💻</a></td> - <td align="center"><a href="http://joningi.net"><img src="https://avatars2.githubusercontent.com/u/6115148?v=4?s=100" width="100px;" alt=""/><br />_{<b>Jón Ingi Sveinbjörnsson</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=joningiwork" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/kirill-vlasov"><img src="https://avatars3.githubusercontent.com/u/16112495?v=4?s=100" width="100px;" alt=""/><br />_{<b>Kirill Vlasov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kirill-vlasov" title="Code">💻</a></td> - <td align="center"><a href="http://mitchell-irvin.com"><img src="https://avatars0.githubusercontent.com/u/16233245?v=4?s=100" width="100px;" alt=""/><br />_{<b>Mitchell Irvin</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mitchellirvin" title="Code">💻</a></td> - <td align="center"><a href="https://ranjeet-floyd.github.io"><img src="https://avatars0.githubusercontent.com/u/1992972?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ranjeet</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ranjeet-floyd" title="Code">💻</a></td> - <td align="center"><a href="https://alwayswithme.github.io"><img src="https://avatars3.githubusercontent.com/u/3234786?v=4?s=100" width="100px;" alt=""/><br />_{<b>PhoenixYip</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Alwayswithme" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/MSaifAsif"><img src="https://avatars1.githubusercontent.com/u/6280554?v=4?s=100" width="100px;" alt=""/><br />_{<b>M Saif Asif</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=MSaifAsif" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/kanwarpreet25"><img src="https://avatars0.githubusercontent.com/u/39183641?v=4?s=100" width="100px;" alt=""/><br />_{<b>kanwarpreet25</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kanwarpreet25" title="Code">💻</a></td> - <td align="center"><a href="http://leonmak.me"><img src="https://avatars3.githubusercontent.com/u/13071508?v=4?s=100" width="100px;" alt=""/><br />_{<b>Leon Mak</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=leonmak" title="Code">💻</a></td> - <td align="center"><a href="http://www.wramdemark.se"><img src="https://avatars2.githubusercontent.com/u/7052193?v=4?s=100" width="100px;" alt=""/><br />_{<b>Per Wramdemark</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=perwramdemark" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/waisuan"><img src="https://avatars2.githubusercontent.com/u/10975700?v=4?s=100" width="100px;" alt=""/><br />_{<b>Evan Sia Wai Suan</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=waisuan" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/AnaghaSasikumar"><img src="https://avatars2.githubusercontent.com/u/42939261?v=4?s=100" width="100px;" alt=""/><br />_{<b>AnaghaSasikumar</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=AnaghaSasikumar" title="Code">💻</a></td> - <td align="center"><a href="https://christofferh.com"><img src="https://avatars1.githubusercontent.com/u/767643?v=4?s=100" width="100px;" alt=""/><br />_{<b>Christoffer Hamberg</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=christofferh" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/dgruntz"><img src="https://avatars0.githubusercontent.com/u/1516800?v=4?s=100" width="100px;" alt=""/><br />_{<b>Dominik Gruntz</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dgruntz" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://bitbucket.org/hannespernpeintner/"><img src="https://avatars3.githubusercontent.com/u/1679437?v=4?s=100" width="100px;" alt=""/><br />_{<b>Hannes</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hannespernpeintner" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/leogtzr"><img src="https://avatars0.githubusercontent.com/u/1211969?v=4?s=100" width="100px;" alt=""/><br />_{<b>Leo Gutiérrez Ramírez</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=leogtzr" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/npczwh"><img src="https://avatars0.githubusercontent.com/u/14066422?v=4?s=100" width="100px;" alt=""/><br />_{<b>Zhang WH</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=npczwh" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/oconnelc"><img src="https://avatars0.githubusercontent.com/u/1112973?v=4?s=100" width="100px;" alt=""/><br />_{<b>Christopher O'Connell</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=oconnelc" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/giorgosmav21"><img src="https://avatars2.githubusercontent.com/u/22855493?v=4?s=100" width="100px;" alt=""/><br />_{<b>George Mavroeidis</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=giorgosmav21" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/hbothra15"><img src="https://avatars1.githubusercontent.com/u/7418012?v=4?s=100" width="100px;" alt=""/><br />_{<b>Hemant Bothra</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hbothra15" title="Code">💻</a> <a href="#design-hbothra15" title="Design">🎨</a></td> - <td align="center"><a href="https://www.kevinpeters.net/about/"><img src="https://avatars1.githubusercontent.com/u/12736734?v=4?s=100" width="100px;" alt=""/><br />_{<b>Kevin Peters</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=igeligel" title="Code">💻</a></td> - <td align="center"><a href="https://llorllale.github.io/"><img src="https://avatars1.githubusercontent.com/u/2019896?v=4?s=100" width="100px;" alt=""/><br />_{<b>George Aristy</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=llorllale" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/mookkiah"><img src="https://avatars1.githubusercontent.com/u/8975264?v=4?s=100" width="100px;" alt=""/><br />_{<b>Mahendran Mookkiah</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mookkiah" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Azureyjt"><img src="https://avatars2.githubusercontent.com/u/18476317?v=4?s=100" width="100px;" alt=""/><br />_{<b>Azureyjt</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Azureyjt" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/vehpsr"><img src="https://avatars2.githubusercontent.com/u/3133265?v=4?s=100" width="100px;" alt=""/><br />_<b>gans</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=vehpsr" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/ThatGuyWithTheHat"><img src="https://avatars0.githubusercontent.com/u/24470582?v=4?s=100" width="100px;" alt=""/><br />_<b>Matt</b></a><br /><a href="#content-ThatGuyWithTheHat" title="Content">🖋</a></td> - </tr> - <tr> - <td align="center"><a href="https://www.linkedin.com/in/gopinathlangote/"><img src="https://avatars2.githubusercontent.com/u/10210778?v=4?s=100" width="100px;" alt=""/><br />_{<b>Gopinath Langote</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gopinath-langote" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/hoswey"><img src="https://avatars3.githubusercontent.com/u/3689445?v=4?s=100" width="100px;" alt=""/><br />_{<b>Hoswey</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hoswey" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/amit2103"><img src="https://avatars3.githubusercontent.com/u/7566692?v=4?s=100" width="100px;" alt=""/><br />_{<b>Amit Pandey</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=amit2103" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/gwildor28"><img src="https://avatars0.githubusercontent.com/u/16000365?v=4?s=100" width="100px;" alt=""/><br />_{<b>gwildor28</b>}</a><br /><a href="#content-gwildor28" title="Content">🖋</a></td> - </tr> - <tr> - <td align="center"><a href="https://t.me/paul_docker"><img src="https://avatars1.githubusercontent.com/u/2404785?v=4?s=100" width="100px;" alt=""/><br />_{<b>田浩</b>}</a><br /><a href="#content-llitfkitfk" title="Content">🖋</a></td> - <td align="center"><a href="https://twitter.com/StPitsios"><img src="https://avatars1.githubusercontent.com/u/6773603?v=4?s=100" width="100px;" alt=""/><br />_{<b>Stamatis Pitsios</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=pitsios-s" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/qza"><img src="https://avatars3.githubusercontent.com/u/233149?v=4?s=100" width="100px;" alt=""/><br />_<b>qza</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=qza" title="Code">💻</a></td> - <td align="center"><a href="http://tschis.github.io"><img src="https://avatars1.githubusercontent.com/u/20662669?v=4?s=100" width="100px;" alt=""/><br />_{<b>Rodolfo Forte</b>}</a><br /><a href="#content-Tschis" title="Content">🖋</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/ankurkaushal"><img src="https://avatars2.githubusercontent.com/u/2236616?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ankur Kaushal</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ankurkaushal" title="Code">💻</a></td> - <td align="center"><a href="https://www.linkedin.com/in/ovidijus-okinskas/"><img src="https://avatars0.githubusercontent.com/u/20372387?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ovidijus Okinskas</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=okinskas" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/robertt240"><img src="https://avatars1.githubusercontent.com/u/9137432?v=4?s=100" width="100px;" alt=""/><br />_{<b>Robert Kasperczyk</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=robertt240" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/trautonen"><img src="https://avatars3.githubusercontent.com/u/1641063?v=4?s=100" width="100px;" alt=""/><br />_{<b>Tapio Rautonen</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=trautonen" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="http://vk.com/yuri.orlov"><img src="https://avatars0.githubusercontent.com/u/1595733?v=4?s=100" width="100px;" alt=""/><br />_{<b>Yuri Orlov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=yorlov" title="Code">💻</a></td> - <td align="center"><a href="https://www.linkedin.com/in/varunu28/"><img src="https://avatars0.githubusercontent.com/u/7676016?v=4?s=100" width="100px;" alt=""/><br />_{<b>Varun Upadhyay</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=varunu28" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/PalAditya"><img src="https://avatars2.githubusercontent.com/u/25523604?v=4?s=100" width="100px;" alt=""/><br />_{<b>Aditya Pal</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=PalAditya" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/grzesiekkedzior"><img src="https://avatars3.githubusercontent.com/u/23739158?v=4?s=100" width="100px;" alt=""/><br />_{<b>grzesiekkedzior</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=grzesiekkedzior" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Agrzesiekkedzior" title="Reviewed Pull Requests">👀</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/sivasubramanim"><img src="https://avatars2.githubusercontent.com/u/51107434?v=4?s=100" width="100px;" alt=""/><br />_{<b>Sivasubramani M</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=sivasubramanim" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/d4gg4d"><img src="https://avatars2.githubusercontent.com/u/99457?v=4?s=100" width="100px;" alt=""/><br />_{<b>Sami Airaksinen</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=d4gg4d" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/vertti"><img src="https://avatars0.githubusercontent.com/u/557751?v=4?s=100" width="100px;" alt=""/><br />_{<b>Janne Sinivirta</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=vertti" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/Bobo1239"><img src="https://avatars1.githubusercontent.com/u/2302947?v=4?s=100" width="100px;" alt=""/><br />_{<b>Boris-Chengbiao Zhou</b>}</a><br /><a href="#content-Bobo1239" title="Content">🖋</a></td> - </tr> - <tr> - <td align="center"><a href="https://jahhein.github.io"><img src="https://avatars2.githubusercontent.com/u/10779515?v=4?s=100" width="100px;" alt=""/><br />_{<b>Jacob Hein</b>}</a><br /><a href="#content-Jahhein" title="Content">🖋</a></td> - <td align="center"><a href="https://github.com/iamrichardjones"><img src="https://avatars3.githubusercontent.com/u/14842151?v=4?s=100" width="100px;" alt=""/><br />_{<b>Richard Jones</b>}</a><br /><a href="#content-iamrichardjones" title="Content">🖋</a></td> - <td align="center"><a href="https://rachelcarmena.github.io"><img src="https://avatars0.githubusercontent.com/u/22792183?v=4?s=100" width="100px;" alt=""/><br />_{<b>Rachel M. Carmena</b>}</a><br /><a href="#content-rachelcarmena" title="Content">🖋</a></td> - <td align="center"><a href="https://zd-zero.github.io"><img src="https://avatars0.githubusercontent.com/u/21978370?v=4?s=100" width="100px;" alt=""/><br />_{<b>Zaerald Denze Lungos</b>}</a><br /><a href="#content-zd-zero" title="Content">🖋</a></td> - </tr> - <tr> - <td align="center"><a href="https://webpro.nl"><img src="https://avatars1.githubusercontent.com/u/456426?v=4?s=100" width="100px;" alt=""/><br />_{<b>Lars Kappert</b>}</a><br /><a href="#content-webpro" title="Content">🖋</a></td> - <td align="center"><a href="https://xiaod.info"><img src="https://avatars2.githubusercontent.com/u/21277644?v=4?s=100" width="100px;" alt=""/><br />_{<b>Mike Liu</b>}</a><br /><a href="#translation-xiaod-dev" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/charlesfinley"><img src="https://avatars1.githubusercontent.com/u/6307904?v=4?s=100" width="100px;" alt=""/><br />_{<b>Matt Dolan</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=charlesfinley" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Acharlesfinley" title="Reviewed Pull Requests">👀</a></td> - <td align="center"><a href="https://github.com/MananS77"><img src="https://avatars3.githubusercontent.com/u/21033516?v=4?s=100" width="100px;" alt=""/><br />_<b>Manan</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3AMananS77" title="Reviewed Pull Requests">👀</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/nishant"><img src="https://avatars2.githubusercontent.com/u/15331971?v=4?s=100" width="100px;" alt=""/><br />_{<b>Nishant Arora</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=nishant" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/raja-peeyush-kumar-singh"><img src="https://avatars0.githubusercontent.com/u/5496024?v=4?s=100" width="100px;" alt=""/><br />_{<b>Peeyush</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=raja-peeyush-kumar-singh" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/ravening"><img src="https://avatars1.githubusercontent.com/u/10645273?v=4?s=100" width="100px;" alt=""/><br />_{<b>Rakesh</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ravening" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Aravening" title="Reviewed Pull Requests">👀</a></td> - <td align="center"><a href="https://github.com/vINCENT8888801"><img src="https://avatars0.githubusercontent.com/u/8037883?v=4?s=100" width="100px;" alt=""/><br />_{<b>Wei Seng</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=vINCENT8888801" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://www.linkedin.com/in/ashish-trivedi-218379135/"><img src="https://avatars3.githubusercontent.com/u/23194128?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ashish Trivedi</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ashishtrivedi16" title="Code">💻</a></td> - <td align="center"><a href="https://rayyounghong.com"><img src="https://avatars1.githubusercontent.com/u/41055099?v=4?s=100" width="100px;" alt=""/><br />_{<b>洪月阳</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=RayYH" title="Code">💻</a></td> - <td align="center"><a href="https://xdvrx1.github.io/"><img src="https://avatars0.githubusercontent.com/u/47092464?v=4?s=100" width="100px;" alt=""/><br />_{<b>xdvrx1</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Axdvrx1" title="Reviewed Pull Requests">👀</a> <a href="#ideas-xdvrx1" title="Ideas, Planning, & Feedback">🤔</a></td> - <td align="center"><a href="http://subho.xyz"><img src="https://avatars0.githubusercontent.com/u/13291222?v=4?s=100" width="100px;" alt=""/><br />_{<b>Subhrodip Mohanta</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ohbus" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Aohbus" title="Reviewed Pull Requests">👀</a> <a href="#maintenance-ohbus" title="Maintenance">🚧</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/nahteb"><img src="https://avatars3.githubusercontent.com/u/13121570?v=4?s=100" width="100px;" alt=""/><br />_{<b>Bethan Palmer</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=nahteb" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/ToxicDreamz"><img src="https://avatars0.githubusercontent.com/u/45225562?v=4?s=100" width="100px;" alt=""/><br />_{<b>Toxic Dreamz</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ToxicDreamz" title="Code">💻</a></td> - <td align="center"><a href="http://www.edycutjong.com"><img src="https://avatars1.githubusercontent.com/u/1098102?v=4?s=100" width="100px;" alt=""/><br />_{<b>Edy Cu Tjong</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=edycutjong" title="Documentation">📖</a></td> - <td align="center"><a href="https://github.com/mkrzywanski"><img src="https://avatars0.githubusercontent.com/u/15279585?v=4?s=100" width="100px;" alt=""/><br />_{<b>Michał Krzywański</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mkrzywanski" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://www.stefan-birkner.de"><img src="https://avatars1.githubusercontent.com/u/711349?v=4?s=100" width="100px;" alt=""/><br />_{<b>Stefan Birkner</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=stefanbirkner" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/fedorskvorcov"><img src="https://avatars3.githubusercontent.com/u/43882212?v=4?s=100" width="100px;" alt=""/><br />_{<b>Fedor Skvorcov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=fedorskvorcov" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/samilAyoub"><img src="https://avatars0.githubusercontent.com/u/61546990?v=4?s=100" width="100px;" alt=""/><br />_{<b>samilAyoub</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=samilAyoub" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/vdlald"><img src="https://avatars0.githubusercontent.com/u/29997701?v=4?s=100" width="100px;" alt=""/><br />_{<b>Vladislav Golubinov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=vdlald" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/swarajsaaj"><img src="https://avatars2.githubusercontent.com/u/6285049?v=4?s=100" width="100px;" alt=""/><br />_{<b>Swaraj</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=swarajsaaj" title="Code">💻</a></td> - <td align="center"><a href="http://christophflick.de"><img src="https://avatars0.githubusercontent.com/u/4465376?v=4?s=100" width="100px;" alt=""/><br />_{<b>Christoph Flick</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ChFlick" title="Documentation">📖</a></td> - <td align="center"><a href="https://github.com/Ascenio"><img src="https://avatars1.githubusercontent.com/u/7662016?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ascênio</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3AAscenio" title="Reviewed Pull Requests">👀</a></td> - <td align="center"><a href="https://www.linkedin.com/in/domenico-sibilio/"><img src="https://avatars2.githubusercontent.com/u/24280982?v=4?s=100" width="100px;" alt=""/><br />_{<b>Domenico Sibilio</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dsibilio" title="Documentation">📖</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/akashchandwani"><img src="https://avatars2.githubusercontent.com/u/3483277?v=4?s=100" width="100px;" alt=""/><br />_{<b>Akash Chandwani</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Aakashchandwani" title="Reviewed Pull Requests">👀</a></td> - <td align="center"><a href="http://www.linkedin.com/in/manannikov"><img src="https://avatars2.githubusercontent.com/u/7019769?v=4?s=100" width="100px;" alt=""/><br />_{<b>Pavlo Manannikov</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=manannikov" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/eimanip"><img src="https://avatars0.githubusercontent.com/u/20307301?v=4?s=100" width="100px;" alt=""/><br />_<b>Eiman</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=eimanip" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/OrangePants-R"><img src="https://avatars0.githubusercontent.com/u/42976136?v=4?s=100" width="100px;" alt=""/><br />_<b>Rocky</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=OrangePants-R" title="Documentation">📖</a></td> - </tr> - <tr> - <td align="center"><a href="https://ibrahimalii.github.io/"><img src="https://avatars2.githubusercontent.com/u/21141301?v=4?s=100" width="100px;" alt=""/><br />_{<b>Ibrahim ali abdelghany</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3AibrahimAlii" title="Reviewed Pull Requests">👀</a></td> - <td align="center"><a href="https://github.com/gkulkarni2020"><img src="https://avatars3.githubusercontent.com/u/5161548?v=4?s=100" width="100px;" alt=""/><br />_{<b>Girish Kulkarni</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gkulkarni2020" title="Documentation">📖</a></td> - <td align="center"><a href="https://github.com/omk13"><img src="https://avatars0.githubusercontent.com/u/59054172?v=4?s=100" width="100px;" alt=""/><br />_{<b>Omar Karazoun</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=omk13" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/jeff303"><img src="https://avatars0.githubusercontent.com/u/3521562?v=4?s=100" width="100px;" alt=""/><br />_{<b>Jeff Evans</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=jeff303" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://viveksb007.github.io"><img src="https://avatars1.githubusercontent.com/u/12713808?v=4?s=100" width="100px;" alt=""/><br />_{<b>Vivek Singh</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=viveksb007" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/siavashsoleymani"><img src="https://avatars2.githubusercontent.com/u/18074419?v=4?s=100" width="100px;" alt=""/><br />_{<b>siavash</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=siavashsoleymani" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/ruchpeanuts"><img src="https://avatars0.githubusercontent.com/u/29301900?v=4?s=100" width="100px;" alt=""/><br />_{<b>ruchpeanuts</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ruchpeanuts" title="Documentation">📖</a></td> - <td align="center"><a href="https://github.com/warp125"><img src="https://avatars1.githubusercontent.com/u/48073115?v=4?s=100" width="100px;" alt=""/><br />_{<b>warp125</b>}</a><br /><a href="#translation-warp125" title="Translation">🌍</a></td> - </tr> - <tr> - <td align="center"><a href="http://libkhadir.fr"><img src="https://avatars1.githubusercontent.com/u/45130488?v=4?s=100" width="100px;" alt=""/><br />_{<b>KHADIR Tayeb</b>}</a><br /><a href="#translation-tkhadir" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/ignite1771"><img src="https://avatars2.githubusercontent.com/u/59446563?v=4?s=100" width="100px;" alt=""/><br />_{<b>ignite1771</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ignite1771" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/demirhalil"><img src="https://avatars1.githubusercontent.com/u/22895118?v=4?s=100" width="100px;" alt=""/><br />_{<b>Halil Demir</b>}</a><br /><a href="#translation-demirhalil" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/rohit10000"><img src="https://avatars.githubusercontent.com/u/20845565?v=4?s=100" width="100px;" alt=""/><br />_{<b>Rohit Singh</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=rohit10000" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/byoungju94"><img src="https://avatars.githubusercontent.com/u/42516378?v=4?s=100" width="100px;" alt=""/><br />_{<b>byoungju94</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=byoungju94" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/moustafafarhat"><img src="https://avatars.githubusercontent.com/u/38836727?v=4?s=100" width="100px;" alt=""/><br />_{<b>Moustafa Farhat</b>}</a><br /><a href="#translation-moustafafarhat" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/richardmr36"><img src="https://avatars.githubusercontent.com/u/19147333?v=4?s=100" width="100px;" alt=""/><br />_{<b>Martel Richard</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=richardmr36" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/va1m"><img src="https://avatars.githubusercontent.com/u/17025445?v=4?s=100" width="100px;" alt=""/><br />_<b>va1m</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=va1m" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/noamgrinch"><img src="https://avatars.githubusercontent.com/u/31648669?v=4?s=100" width="100px;" alt=""/><br />_{<b>Noam Greenshtain</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=noamgrinch" title="Code">💻</a></td> - <td align="center"><a href="https://xuyonghong.cn/"><img src="https://avatars.githubusercontent.com/u/14086462?v=4?s=100" width="100px;" alt=""/><br />_{<b>yonghong Xu</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=qfxl" title="Documentation">📖</a></td> - <td align="center"><a href="https://www.linkedin.com/in/jinisha-vora"><img src="https://avatars.githubusercontent.com/u/40777762?v=4?s=100" width="100px;" alt=""/><br />_{<b>jinishavora</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Ajinishavora" title="Reviewed Pull Requests">👀</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=jinishavora" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/eas5"><img src="https://avatars.githubusercontent.com/u/50836521?v=4?s=100" width="100px;" alt=""/><br />_{<b>Elvys Soares</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=eas5" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/zWeBrain"><img src="https://avatars.githubusercontent.com/u/46642512?v=4?s=100" width="100px;" alt=""/><br />_{<b>zWeBrain</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=zWeBrain" title="Code">💻</a></td> - <td align="center"><a href="https://al-assad.github.io/notion/"><img src="https://avatars.githubusercontent.com/u/22493821?v=4?s=100" width="100px;" alt=""/><br />_{<b>余林颖</b>}</a><br /><a href="#translation-Al-assad" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/STudio26"><img src="https://avatars.githubusercontent.com/u/6988911?v=4?s=100" width="100px;" alt=""/><br />_<b>Alain</b></a><br /><a href="#translation-STudio26" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/DEV-VRUPER"><img src="https://avatars.githubusercontent.com/u/30525467?v=4?s=100" width="100px;" alt=""/><br />_<b>VR</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=DEV-VRUPER" title="Documentation">📖</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/JackieNim"><img src="https://avatars.githubusercontent.com/u/4138836?v=4?s=100" width="100px;" alt=""/><br />_{<b>JackieNim</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=JackieNim" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/EdisonE3"><img src="https://avatars.githubusercontent.com/u/52118917?v=4?s=100" width="100px;" alt=""/><br />_{<b>EdisonE3</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=EdisonE3" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/tao-sun2"><img src="https://avatars.githubusercontent.com/u/66189688?v=4?s=100" width="100px;" alt=""/><br />_<b>Tao</b></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=tao-sun2" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/JuanManuelAbate"><img src="https://avatars.githubusercontent.com/u/16357060?v=4?s=100" width="100px;" alt=""/><br />_{<b>Juan Manuel Abate</b>}</a><br /><a href="#translation-JuanManuelAbate" title="Translation">🌍</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/Xenilo137"><img src="https://avatars.githubusercontent.com/u/24865069?v=4?s=100" width="100px;" alt=""/><br />_{<b>Xenilo137</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Xenilo137" title="Code">💻</a></td> - <td align="center"><a href="https://www.linkedin.com/in/souzasamuel/"><img src="https://avatars.githubusercontent.com/u/17254162?v=4?s=100" width="100px;" alt=""/><br />_{<b>Samuel Souza</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=samuelpsouza" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/marlo2222"><img src="https://avatars.githubusercontent.com/u/40809563?v=4?s=100" width="100px;" alt=""/><br />_{<b>Marlo Henrique</b>}</a><br /><a href="#translation-marlo2222" title="Translation">🌍</a></td> - <td align="center"><a href="https://github.com/AndriyPyzh"><img src="https://avatars.githubusercontent.com/u/57706635?v=4?s=100" width="100px;" alt=""/><br />_{<b>AndriyPyzh</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=AndriyPyzh" title="Code">💻</a></td> - </tr> - <tr> - <td align="center"><a href="https://github.com/karthikbhat13"><img src="https://avatars.githubusercontent.com/u/22431014?v=4?s=100" width="100px;" alt=""/><br />_{<b>karthikbhat13</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=karthikbhat13" title="Code">💻</a></td> - <td align="center"><a href="https://github.com/mortezaadi"><img src="https://avatars.githubusercontent.com/u/1329687?v=4?s=100" width="100px;" alt=""/><br />_{<b>Morteza Adigozalpour</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mortezaadi" title="Code">💻</a></td> - <td align="center"><a href="https://stackoverflow.com/users/308565/nagaraj-tantri"><img src="https://avatars.githubusercontent.com/u/3784194?v=4?s=100" width="100px;" alt=""/><br />_{<b>Nagaraj Tantri</b>}</a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=tan31989" title="Code">💻</a></td> - </tr> -</table> + +<a href="https://github.com/iluwatar/java-design-patterns/graphs/contributors"> + <img src="https://contributors-img.web.app/image?repo=iluwatar/java-design-patterns&max=250" /> +</a> <!-- markdownlint-restore --> <!-- prettier-ignore-end -->

train

train

chandrikadeb7

train

iluwatar/java-design-patterns/1803_1828

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1803

iluwatar/java-design-patterns/1828

42eb7950aef44e00b9a5363e681762a1bf1271c3

57f9c2e9687d959a9753297ab7641ded639947da

Update Lombok version (possible migration issue for JDK17)

Lombok does not work in the current master branch when using JDK16. `[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project abstract-factory: Fatal error compiling: java.lang.IllegalAccessError: class lombok.javac.apt.LombokProcessor (in unnamed module @0x4809c771) cannot access class com.sun.tools.javac.processing.JavacProcessingEnvironment (in module jdk.compiler) because module jdk.compiler does not export com.sun.tools.javac.processing to unnamed module @0x4809c771 -> [Help 1]` To fix it i used: ``` diff --git a/pom.xml b/pom.xml index 31cf03b4d..d7f05d796 100644 --- a/pom.xml +++ b/pom.xml @@ -71,7 +71,7 @@ <system-lambda.version>1.1.0</system-lambda.version> <urm.version>2.0.0</urm.version> <mockito-junit-jupiter.version>3.5.0</mockito-junit-jupiter.version> - <lombok.version>1.18.14</lombok.version> + <lombok.version>1.18.20</lombok.version> <byte-buddy.version>1.10.21</byte-buddy.version> <javassist.version>3.27.0-GA</javassist.version> <maven-surefire-plugin.version>3.0.0-M5</maven-surefire-plugin.version> ```

diff --git a/pom.xml b/pom.xml index cb726a43e352..3e5e51abfbc5 100644 --- a/pom.xml +++ b/pom.xml @@ -71,7 +71,7 @@ <system-lambda.version>1.1.0</system-lambda.version> <urm.version>2.0.0</urm.version> <mockito-junit-jupiter.version>3.5.0</mockito-junit-jupiter.version> - <lombok.version>1.18.14</lombok.version> + <lombok.version>1.18.20</lombok.version> <byte-buddy.version>1.11.5</byte-buddy.version> <javassist.version>3.27.0-GA</javassist.version> <maven-surefire-plugin.version>3.0.0-M5</maven-surefire-plugin.version>

train

train

beooo79

train

iluwatar/java-design-patterns/1012_1833

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1012

iluwatar/java-design-patterns/1833

ddb9b14eedfe317e4c95571bc5197f2e5e1ed596

5a644f1092079f4f0152641b704dec1d668727ff

SonarCloud reports issues

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blockers and critical severity code smells (major, minor, and info level we ignore). In this task, those are fixed or marked as false positives. To mark false positives, SuppressWarnings annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity code smells in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=CODE_SMELL) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues) *** Note: When Submitting a PR please provide a **hyperlinked** list of all the issues that you are issuing a fix for. [_See this example_](https://github.com/iluwatar/java-design-patterns/pull/1833#issue-1015516036)

diff --git a/async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java b/async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java index b7d5e386b83a..ca63520be298 100644 --- a/async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java +++ b/async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java @@ -59,9 +59,12 @@ @Slf4j public class App { + private static final String ROCKET_LAUNCH_LOG_PATTERN = "Space rocket <%s> launched successfully"; + /** * Program entry point. */ + public static void main(String[] args) throws Exception { // construct a new executor that will run async tasks var executor = new ThreadAsyncExecutor(); @@ -87,9 +90,9 @@ public static void main(String[] args) throws Exception { asyncResult5.await(); // log the results of the tasks, callbacks log immediately when complete - log("Space rocket <" + result1 + "> launch complete"); - log("Space rocket <" + result2 + "> launch complete"); - log("Space rocket <" + result3 + "> launch complete"); + log(String.format(ROCKET_LAUNCH_LOG_PATTERN, result1)); + log(String.format(ROCKET_LAUNCH_LOG_PATTERN, result2)); + log(String.format(ROCKET_LAUNCH_LOG_PATTERN, result3)); } /** @@ -102,7 +105,7 @@ public static void main(String[] args) throws Exception { private static <T> Callable<T> lazyval(T value, long delayMillis) { return () -> { Thread.sleep(delayMillis); - log("Space rocket <" + value + "> launched successfully"); + log(String.format(ROCKET_LAUNCH_LOG_PATTERN, value)); return value; }; } diff --git a/bytecode/src/main/java/com/iluwatar/bytecode/App.java b/bytecode/src/main/java/com/iluwatar/bytecode/App.java index f76a8e6a4f87..43ddd4b9dc72 100644 --- a/bytecode/src/main/java/com/iluwatar/bytecode/App.java +++ b/bytecode/src/main/java/com/iluwatar/bytecode/App.java @@ -42,6 +42,14 @@ @Slf4j public class App { + private static final String LITERAL_0 = "LITERAL 0"; + private static final String HEALTH_PATTERN = "%s_HEALTH"; + private static final String GET_AGILITY = "GET_AGILITY"; + private static final String GET_WISDOM = "GET_WISDOM"; + private static final String ADD = "ADD"; + private static final String LITERAL_2 = "LITERAL 2"; + private static final String DIVIDE = "DIVIDE"; + /** * Main app method. * @@ -53,17 +61,17 @@ public static void main(String[] args) { new Wizard(45, 7, 11, 0, 0), new Wizard(36, 18, 8, 0, 0)); - vm.execute(InstructionConverterUtil.convertToByteCode("LITERAL 0")); - vm.execute(InstructionConverterUtil.convertToByteCode("LITERAL 0")); - vm.execute(InstructionConverterUtil.convertToByteCode("GET_HEALTH")); - vm.execute(InstructionConverterUtil.convertToByteCode("LITERAL 0")); - vm.execute(InstructionConverterUtil.convertToByteCode("GET_AGILITY")); - vm.execute(InstructionConverterUtil.convertToByteCode("LITERAL 0")); - vm.execute(InstructionConverterUtil.convertToByteCode("GET_WISDOM")); - vm.execute(InstructionConverterUtil.convertToByteCode("ADD")); - vm.execute(InstructionConverterUtil.convertToByteCode("LITERAL 2")); - vm.execute(InstructionConverterUtil.convertToByteCode("DIVIDE")); - vm.execute(InstructionConverterUtil.convertToByteCode("ADD")); - vm.execute(InstructionConverterUtil.convertToByteCode("SET_HEALTH")); + vm.execute(InstructionConverterUtil.convertToByteCode(LITERAL_0)); + vm.execute(InstructionConverterUtil.convertToByteCode(LITERAL_0)); + vm.execute(InstructionConverterUtil.convertToByteCode(String.format(HEALTH_PATTERN, "GET"))); + vm.execute(InstructionConverterUtil.convertToByteCode(LITERAL_0)); + vm.execute(InstructionConverterUtil.convertToByteCode(GET_AGILITY)); + vm.execute(InstructionConverterUtil.convertToByteCode(LITERAL_0)); + vm.execute(InstructionConverterUtil.convertToByteCode(GET_WISDOM)); + vm.execute(InstructionConverterUtil.convertToByteCode(ADD)); + vm.execute(InstructionConverterUtil.convertToByteCode(LITERAL_2)); + vm.execute(InstructionConverterUtil.convertToByteCode(DIVIDE)); + vm.execute(InstructionConverterUtil.convertToByteCode(ADD)); + vm.execute(InstructionConverterUtil.convertToByteCode(String.format(HEALTH_PATTERN, "SET"))); } } diff --git a/caching/src/main/java/com/iluwatar/caching/DbManager.java b/caching/src/main/java/com/iluwatar/caching/DbManager.java index d0223496948c..3284d3118fdf 100644 --- a/caching/src/main/java/com/iluwatar/caching/DbManager.java +++ b/caching/src/main/java/com/iluwatar/caching/DbManager.java @@ -50,6 +50,7 @@ public final class DbManager { private static boolean useMongoDB; private static Map<String, UserAccount> virtualDB; + private static final String ERROR_MESSAGE_LOG = "Error connecting to MongoDB"; private DbManager() { } @@ -85,7 +86,7 @@ public static UserAccount readFromDb(String userId) { try { connect(); } catch (ParseException e) { - LOGGER.error("Error connecting to MongoDB", e); + LOGGER.error(ERROR_MESSAGE_LOG, e); } } var iterable = db @@ -112,7 +113,7 @@ public static void writeToDb(UserAccount userAccount) { try { connect(); } catch (ParseException e) { - LOGGER.error("Error connecting to MongoDB", e); + LOGGER.error(ERROR_MESSAGE_LOG, e); } } db.getCollection(CachingConstants.USER_ACCOUNT).insertOne( @@ -134,7 +135,7 @@ public static void updateDb(UserAccount userAccount) { try { connect(); } catch (ParseException e) { - LOGGER.error("Error connecting to MongoDB", e); + LOGGER.error(ERROR_MESSAGE_LOG, e); } } db.getCollection(CachingConstants.USER_ACCOUNT).updateOne( @@ -155,7 +156,7 @@ public static void upsertDb(UserAccount userAccount) { try { connect(); } catch (ParseException e) { - LOGGER.error("Error connecting to MongoDB", e); + LOGGER.error(ERROR_MESSAGE_LOG, e); } } db.getCollection(CachingConstants.USER_ACCOUNT).updateOne(

train

train

iluwatar

train

iluwatar/java-design-patterns/1875_1879

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1875

iluwatar/java-design-patterns/1879

90b1b922e1f60b25e73493f6f71fa6ad8a10fdee

72bb189dc06d8edd4e8e3ef1a92b9201043087cd

Make a separate build line in for Sonar analysis

I have overlooked that there will be two simultaneous reports generated for Sonar issues which I have overlooked. - [ ] Dismiss Matrix building of the project. - [ ] We need to split into two build pipelines, one for running sonar analysis against the latest `zulu` build, and one with the latest JDK build. - [ ] Let us use the cache feature for `maven` dependencies. _Originally posted by @ohbus in https://github.com/iluwatar/java-design-patterns/pull/1868#pullrequestreview-785844000_

diff --git a/.github/workflows/maven-ci.yml b/.github/workflows/maven-ci.yml index 94406095e02a..3b1bcafb0630 100644 --- a/.github/workflows/maven-ci.yml +++ b/.github/workflows/maven-ci.yml @@ -24,6 +24,9 @@ # This workflow will build a Java project with Maven # For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven +# We are using two jobs here for testing our code on the latest JDK 11 build as well as a more satble build version of 11.0.3 +# You can see the full discussion here https://github.com/iluwatar/java-design-patterns/pull/1868#issue-1029459688 + name: Java CI on: @@ -33,12 +36,11 @@ on: jobs: - build: + # This Workflow Job will build this project and run Sonar analysis using JDK 11.0.3 + build-and-analyze: + name: Build and Run Sonar analysis on JDK 11.0.3 runs-on: ubuntu-20.04 - strategy: - matrix: - java-version: [ 11.0.3, 11 ] steps: - name: Checkout Code @@ -47,12 +49,14 @@ jobs: # Disabling shallow clone for improving relevancy of SonarQube reporting fetch-depth: 0 - - name: Set up JDK ${{ matrix.java-version }} + - name: Set up JDK 11.0.3 uses: actions/setup-java@v2 with: - java-version: ${{ matrix.java-version }} + java-version: 11.0.3 distribution: 'zulu' + cache: 'maven' + # Cache Sonar packages which as used to run anaylysis and collect metrics - name: Cache SonarCloud packages uses: actions/cache@v2 with: @@ -60,14 +64,6 @@ jobs: key: ${{ runner.os }}-sonar restore-keys: ${{ runner.os }}-sonar - - name: Cache Maven dependencies - uses: actions/cache@v2 - with: - path: ~/.m2/repository - key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }} - restore-keys: | - ${{ runner.os }}-maven- - # Some tests need screen access - name: Install xvfb run: sudo apt-get install -y xvfb @@ -78,3 +74,28 @@ jobs: # These two env variables are needed for sonar analysis GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }} + + + # This Workflow Job is going to build the project on the latest stable JDK 11 + build: + + name: Build and Test on JDK 11 + runs-on: ubuntu-20.04 + steps: + + - name: Checkout Code + uses: actions/checkout@v2 + + - name: Set up JDK 11 (Latest) + uses: actions/setup-java@v2 + with: + java-version: 11 + distribution: 'zulu' + cache: 'maven' + + # Some tests need screen access + - name: Install xvfb + run: sudo apt-get install -y xvfb + + - name: Build with Maven + run: xvfb-run ./mvnw clean verify diff --git a/.github/workflows/maven-pr-builder.yml b/.github/workflows/maven-pr-builder.yml index c1fd2bd82beb..8e5c5d9c7ced 100644 --- a/.github/workflows/maven-pr-builder.yml +++ b/.github/workflows/maven-pr-builder.yml @@ -34,11 +34,13 @@ on: jobs: build: + name: Build JDP runs-on: ubuntu-20.04 strategy: matrix: java-version: [ 11.0.3, 11 ] steps: + - name: Checkout Code uses: actions/checkout@v2 @@ -47,14 +49,7 @@ jobs: with: java-version: ${{ matrix.java-version }} distribution: 'zulu' - - - name: Cache Maven Dependecies - uses: actions/cache@v2 - with: - path: ~/.m2/repository - key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }} - restore-keys: | - ${{ runner.os }}-maven- + cache: 'maven' # Some tests need screen access - name: Install xvfb

train

train

ohbus

train

iluwatar/java-design-patterns/1012_1896

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1012

iluwatar/java-design-patterns/1896

bee1283371d25dd5f0c5e7d4bac66b4c05f9aeac

36c6ce1df7f0008c71d82a6eb784df788505a9b3

SonarCloud reports issues

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blockers and critical severity code smells (major, minor, and info level we ignore). In this task, those are fixed or marked as false positives. To mark false positives, SuppressWarnings annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity code smells in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=CODE_SMELL) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues) *** Note: When Submitting a PR please provide a **hyperlinked** list of all the issues that you are issuing a fix for. [_See this example_](https://github.com/iluwatar/java-design-patterns/pull/1833#issue-1015516036)

diff --git a/factory-method/src/main/java/com/iluwatar/factory/method/App.java b/factory-method/src/main/java/com/iluwatar/factory/method/App.java index b76a918d1876..d903ee7c7fee 100644 --- a/factory-method/src/main/java/com/iluwatar/factory/method/App.java +++ b/factory-method/src/main/java/com/iluwatar/factory/method/App.java @@ -41,6 +41,8 @@ @Slf4j public class App { + private static final String MANUFACTURED = "{} manufactured {}"; + /** * Program entry point. * @param args command line args @@ -49,14 +51,14 @@ public static void main(String[] args) { Blacksmith blacksmith = new OrcBlacksmith(); Weapon weapon = blacksmith.manufactureWeapon(WeaponType.SPEAR); - LOGGER.info("{} manufactured {}", blacksmith, weapon); + LOGGER.info(MANUFACTURED, blacksmith, weapon); weapon = blacksmith.manufactureWeapon(WeaponType.AXE); - LOGGER.info("{} manufactured {}", blacksmith, weapon); + LOGGER.info(MANUFACTURED, blacksmith, weapon); blacksmith = new ElfBlacksmith(); weapon = blacksmith.manufactureWeapon(WeaponType.SPEAR); - LOGGER.info("{} manufactured {}", blacksmith, weapon); + LOGGER.info(MANUFACTURED, blacksmith, weapon); weapon = blacksmith.manufactureWeapon(WeaponType.AXE); - LOGGER.info("{} manufactured {}", blacksmith, weapon); + LOGGER.info(MANUFACTURED, blacksmith, weapon); } }

train

train

iluwatar

train

iluwatar/java-design-patterns/1012_1898

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1012

iluwatar/java-design-patterns/1898

72bb189dc06d8edd4e8e3ef1a92b9201043087cd

22ddd571467f811e120d37a43dae0edbc9071779

SonarCloud reports issues

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blockers and critical severity code smells (major, minor, and info level we ignore). In this task, those are fixed or marked as false positives. To mark false positives, SuppressWarnings annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity code smells in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=CODE_SMELL) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues) *** Note: When Submitting a PR please provide a **hyperlinked** list of all the issues that you are issuing a fix for. [_See this example_](https://github.com/iluwatar/java-design-patterns/pull/1833#issue-1015516036)

diff --git a/strategy/src/main/java/com/iluwatar/strategy/App.java b/strategy/src/main/java/com/iluwatar/strategy/App.java index 383712c39806..d54c06008692 100644 --- a/strategy/src/main/java/com/iluwatar/strategy/App.java +++ b/strategy/src/main/java/com/iluwatar/strategy/App.java @@ -41,6 +41,10 @@ @Slf4j public class App { + private static final String RED_DRAGON_EMERGES = "Red dragon emerges."; + private static final String GREEN_DRAGON_SPOTTED = "Green dragon spotted ahead!"; + private static final String BLACK_DRAGON_LANDS = "Black dragon lands before you."; + /** * Program entry point. * @@ -48,38 +52,38 @@ public class App { */ public static void main(String[] args) { // GoF Strategy pattern - LOGGER.info("Green dragon spotted ahead!"); + LOGGER.info(GREEN_DRAGON_SPOTTED); var dragonSlayer = new DragonSlayer(new MeleeStrategy()); dragonSlayer.goToBattle(); - LOGGER.info("Red dragon emerges."); + LOGGER.info(RED_DRAGON_EMERGES); dragonSlayer.changeStrategy(new ProjectileStrategy()); dragonSlayer.goToBattle(); - LOGGER.info("Black dragon lands before you."); + LOGGER.info(BLACK_DRAGON_LANDS); dragonSlayer.changeStrategy(new SpellStrategy()); dragonSlayer.goToBattle(); // Java 8 functional implementation Strategy pattern - LOGGER.info("Green dragon spotted ahead!"); + LOGGER.info(GREEN_DRAGON_SPOTTED); dragonSlayer = new DragonSlayer( () -> LOGGER.info("With your Excalibur you severe the dragon's head!")); dragonSlayer.goToBattle(); - LOGGER.info("Red dragon emerges."); + LOGGER.info(RED_DRAGON_EMERGES); dragonSlayer.changeStrategy(() -> LOGGER.info( "You shoot the dragon with the magical crossbow and it falls dead on the ground!")); dragonSlayer.goToBattle(); - LOGGER.info("Black dragon lands before you."); + LOGGER.info(BLACK_DRAGON_LANDS); dragonSlayer.changeStrategy(() -> LOGGER.info( "You cast the spell of disintegration and the dragon vaporizes in a pile of dust!")); dragonSlayer.goToBattle(); // Java 8 lambda implementation with enum Strategy pattern - LOGGER.info("Green dragon spotted ahead!"); + LOGGER.info(GREEN_DRAGON_SPOTTED); dragonSlayer.changeStrategy(LambdaStrategy.Strategy.MeleeStrategy); dragonSlayer.goToBattle(); - LOGGER.info("Red dragon emerges."); + LOGGER.info(RED_DRAGON_EMERGES); dragonSlayer.changeStrategy(LambdaStrategy.Strategy.ProjectileStrategy); dragonSlayer.goToBattle(); - LOGGER.info("Black dragon lands before you."); + LOGGER.info(BLACK_DRAGON_LANDS); dragonSlayer.changeStrategy(LambdaStrategy.Strategy.SpellStrategy); dragonSlayer.goToBattle(); }

train

train

iluwatar

train

iluwatar/java-design-patterns/1908_1909

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1908

iluwatar/java-design-patterns/1909

0a7b524bd10b0eb67ac6045d12415759b1dc7fd0

89b20721316f256994c3194b8dedb589ca6b7362

Concurrency problems in leader-followers pattern

I have found a bug in the leader-followers pattern during unit test. In the state of concurrency, there is a small chance that no new leader will be promoted. The reason is that in the worker class, there is no double check before calling the wait method of workercenter. It causes the thread which should become leader mistakenly believe that the leader already exists and waits.

diff --git a/leader-followers/src/main/java/com/iluwatar/leaderfollowers/Worker.java b/leader-followers/src/main/java/com/iluwatar/leaderfollowers/Worker.java index 6c7caed244b7..21326bb0a77c 100644 --- a/leader-followers/src/main/java/com/iluwatar/leaderfollowers/Worker.java +++ b/leader-followers/src/main/java/com/iluwatar/leaderfollowers/Worker.java @@ -57,9 +57,11 @@ public void run() { try { if (workCenter.getLeader() != null && !workCenter.getLeader().equals(this)) { synchronized (workCenter) { - workCenter.wait(); + if (workCenter.getLeader() != null && !workCenter.getLeader().equals(this)) { + workCenter.wait(); + continue; + } } - continue; } final Task task = taskSet.getTask(); synchronized (workCenter) {

train

train

npczwh

train

iluwatar/java-design-patterns/1871_1956

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1871

iluwatar/java-design-patterns/1956

dde31bfe349fabf800c2ddcf0ac36e69acf8bf8c

b51bca1a6744f2d18d69f52047e70fd5948131f7

Monitor pattern is not being built

In https://github.com/iluwatar/java-design-patterns/pull/1640 we merged the monitor pattern but noticed that it's not included in the main `pom.xml` and not being built. Let's fix that in this issue.

diff --git a/monitor/pom.xml b/monitor/pom.xml index f337350190a0..9246f33caff9 100644 --- a/monitor/pom.xml +++ b/monitor/pom.xml @@ -21,9 +21,9 @@ <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> - <artifactId>java-design-patterns</artifactId> <groupId>com.iluwatar</groupId> - <version>1.24.0-SNAPSHOT</version> + <artifactId>java-design-patterns</artifactId> + <version>1.26.0-SNAPSHOT</version> </parent> <artifactId>monitor</artifactId> <dependencies> diff --git a/monitor/src/main/java/com/iluwatar/monitor/Bank.java b/monitor/src/main/java/com/iluwatar/monitor/Bank.java index d4defa6d16ca..3652129657b6 100644 --- a/monitor/src/main/java/com/iluwatar/monitor/Bank.java +++ b/monitor/src/main/java/com/iluwatar/monitor/Bank.java @@ -1,37 +1,87 @@ +/* +*The MIT License +*Copyright © 2014-2021 Ilkka Seppälä +* +*Permission is hereby granted, free of charge, to any person obtaining a copy +*of this software and associated documentation files (the "Software"), to deal +*in the Software without restriction, including without limitation the rights +*to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +*copies of the Software, and to permit persons to whom the Software is +*furnished to do so, subject to the following conditions: +* +*The above copyright notice and this permission notice shall be included in +*all copies or substantial portions of the Software. +* +*THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +*IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +*FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +*AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +*LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +*OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +*THE SOFTWARE. +*/ + package com.iluwatar.monitor; import java.util.Arrays; -import java.util.logging.Logger; +import lombok.extern.slf4j.Slf4j; -// Bank class implements the Monitor pattern +/** Bank Definition. */ +@Slf4j public class Bank { - private int[] accounts; - Logger logger; + private final int[] accounts; - public Bank(int accountNum, int baseAmount, Logger logger) { - this.logger = logger; - accounts = new int[accountNum]; - Arrays.fill(accounts, baseAmount); - } + /** + * Constructor. + * + * @param accountNum - account number + * @param baseAmount - base amount + */ + public Bank(int accountNum, int baseAmount) { + accounts = new int[accountNum]; + Arrays.fill(accounts, baseAmount); + } - public synchronized void transfer(int accountA, int accountB, int amount) { - if (accounts[accountA] >= amount) { - accounts[accountB] += amount; - accounts[accountA] -= amount; - logger.info("Transferred from account :" + accountA + " to account :" + accountB + " , amount :" + amount + " . balance :" + getBalance()); - } + /** + * Transfer amounts from one account to another. + * + * @param accountA - source account + * @param accountB - destination account + * @param amount - amount to be transferred + */ + public synchronized void transfer(int accountA, int accountB, int amount) { + if (accounts[accountA] >= amount) { + accounts[accountB] += amount; + accounts[accountA] -= amount; + LOGGER.info( + "Transferred from account: {} to account: {} , amount: {} , balance: {}", + accountA, + accountB, + amount, + getBalance()); } + } - public synchronized int getBalance() { - int balance = 0; - for (int account : accounts) { - balance += account; - } - return balance; + /** + * Calculates the total balance. + * + * @return balance + */ + public synchronized int getBalance() { + int balance = 0; + for (int account : accounts) { + balance += account; } + return balance; + } - public int[] getAccounts() { - return accounts; - } + /** + * Get all accounts. + * + * @return accounts + */ + public int[] getAccounts() { + return accounts; + } } diff --git a/monitor/src/main/java/com/iluwatar/monitor/Main.java b/monitor/src/main/java/com/iluwatar/monitor/Main.java index c1e1bcccb8d2..317cbd337c73 100644 --- a/monitor/src/main/java/com/iluwatar/monitor/Main.java +++ b/monitor/src/main/java/com/iluwatar/monitor/Main.java @@ -1,60 +1,73 @@ /* - * The MIT License - * Copyright © 2014-2021 Ilkka Seppälä + *The MIT License + *Copyright © 2014-2021 Ilkka Seppälä * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: + *Permission is hereby granted, free of charge, to any person obtaining a copy + *of this software and associated documentation files (the "Software"), to deal + *in the Software without restriction, including without limitation the rights + *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + *copies of the Software, and to permit persons to whom the Software is + *furnished to do so, subject to the following conditions: * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. + *The above copyright notice and this permission notice shall be included in + *all copies or substantial portions of the Software. * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. + *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + *THE SOFTWARE. */ package com.iluwatar.monitor; -import java.util.*; +import java.security.SecureRandom; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; -import java.util.logging.Logger; +import lombok.extern.slf4j.Slf4j; /** - * <p>The Monitor pattern is used in concurrent algorithms to achieve mutual exclusion.</p> + * The Monitor pattern is used in concurrent algorithms to achieve mutual exclusion. * - * <p>Bank is a simple class that transfers money from an account to another account using - * {@link Bank#transfer}. It can also return the balance of the bank account stored in the bank.</p> + * <p>Bank is a simple class that transfers money from an account to another account using {@link + * Bank#transfer}. It can also return the balance of the bank account stored in the bank. * - * <p>Main class uses ThreadPool to run threads that do transactions on the bank accounts.</p> + * <p>Main class uses ThreadPool to run threads that do transactions on the bank accounts. */ - +@Slf4j public class Main { - public static void main(String[] args) { - Logger logger = Logger.getLogger("monitor"); - var bank = new Bank(4, 1000, logger); - Runnable runnable = () -> { - try { - Thread.sleep((long) (Math.random() * 1000)); - Random random = new Random(); - for (int i = 0; i < 1000000; i++) - bank.transfer(random.nextInt(4), random.nextInt(4), (int) (Math.random() * 1000)); - } catch (InterruptedException e) { - logger.info(e.getMessage()); - } - }; - ExecutorService executorService = Executors.newFixedThreadPool(5); - for (int i = 0; i < 5; i++) { - executorService.execute(runnable); - } + /** + * Runner to perform a bunch of transfers and handle exception. + * + * @param bank bank object + */ + public static void runner(Bank bank) { + try { + SecureRandom random = new SecureRandom(); + Thread.sleep(random.nextInt(1000)); + for (int i = 0; i < 1000000; i++) { + bank.transfer(random.nextInt(4), random.nextInt(4), random.nextInt()); + } + } catch (InterruptedException e) { + LOGGER.info(e.getMessage()); + Thread.currentThread().interrupt(); + } + } + + /** + * Program entry point. + * + * @param args command line args + */ + public static void main(String[] args) { + var bank = new Bank(4, 1000); + Runnable runnable = () -> runner(bank); + ExecutorService executorService = Executors.newFixedThreadPool(5); + for (int i = 0; i < 5; i++) { + executorService.execute(runnable); } -} \ No newline at end of file + } +} diff --git a/pom.xml b/pom.xml index e58146c72cd2..064e7c1a7eff 100644 --- a/pom.xml +++ b/pom.xml @@ -85,6 +85,7 @@ </properties> <modules> <module>abstract-factory</module> + <module>monitor</module> <module>tls</module> <module>builder</module> <module>factory-method</module>

diff --git a/monitor/src/main/test/java/com/iluwater/java/BankTest.java b/monitor/src/main/test/java/com/iluwater/java/BankTest.java deleted file mode 100644 index eab7d7a3c59d..000000000000 --- a/monitor/src/main/test/java/com/iluwater/java/BankTest.java +++ /dev/null @@ -1,55 +0,0 @@ -package com.iluwater.java; - -import com.iluwatar.monitor.Bank; -import org.junit.jupiter.api.AfterAll; -import org.junit.jupiter.api.BeforeAll; -import org.junit.jupiter.api.Test; - -import static org.junit.jupiter.api.Assertions.*; -import static org.junit.jupiter.api.Assumptions.*; - -import java.util.logging.Logger; - -public class BankTest { - - private static Bank bank; - private static final int ACCOUNT_NUM = 4; - private static final int BASE_AMOUNT = 1000; - private static final Logger LOGGER = Logger.getLogger("monitor"); - - @BeforeAll - public static void Setup() { - bank = new Bank(ACCOUNT_NUM, BASE_AMOUNT, LOGGER); - } - - @Test - public void GetAccountHaveNotBeNull() { - assertNotNull(bank.getAccounts()); - } - - @Test - public void LengthOfAccountsHaveToEqualsToAccountNumConstant() { - assumeTrue(bank.getAccounts() != null); - assertEquals(ACCOUNT_NUM, bank.getAccounts().length); - } - - @Test - public void TransferMethodHaveToTransferAmountFromAnAccountToOtherAccount() { - bank.transfer(0, 1, 1000); - int accounts[] = bank.getAccounts(); - assertEquals(0, accounts[0]); - assertEquals(2000, 2000); - } - - @Test - public void BalanceHaveToBeOK() { - assertEquals(4000, bank.getBalance()); - } - - - @AfterAll - public static void TearDown() { - bank = null; - } - -} diff --git a/monitor/src/test/java/com/iluwatar/monitor/BankTest.java b/monitor/src/test/java/com/iluwatar/monitor/BankTest.java new file mode 100644 index 000000000000..a961ec091ef6 --- /dev/null +++ b/monitor/src/test/java/com/iluwatar/monitor/BankTest.java @@ -0,0 +1,71 @@ +/* + *The MIT License + *Copyright © 2014-2021 Ilkka Seppälä + * + *Permission is hereby granted, free of charge, to any person obtaining a copy + *of this software and associated documentation files (the "Software"), to deal + *in the Software without restriction, including without limitation the rights + *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + *copies of the Software, and to permit persons to whom the Software is + *furnished to do so, subject to the following conditions: + * + *The above copyright notice and this permission notice shall be included in + *all copies or substantial portions of the Software. + * + *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + *THE SOFTWARE. + */ + +package com.iluwatar.monitor; + +import org.junit.jupiter.api.AfterAll; +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; +import static org.junit.jupiter.api.Assertions.*; +import static org.junit.jupiter.api.Assumptions.*; + +public class BankTest { + + private static final int ACCOUNT_NUM = 4; + private static final int BASE_AMOUNT = 1000; + private static Bank bank; + + @BeforeAll + public static void Setup() { + bank = new Bank(ACCOUNT_NUM, BASE_AMOUNT); + } + + @AfterAll + public static void TearDown() { + bank = null; + } + + @Test + void GetAccountHaveNotBeNull() { + assertNotNull(bank.getAccounts()); + } + + @Test + void LengthOfAccountsHaveToEqualsToAccountNumConstant() { + assumeTrue(bank.getAccounts() != null); + assertEquals(ACCOUNT_NUM, bank.getAccounts().length); + } + + @Test + void TransferMethodHaveToTransferAmountFromAnAccountToOtherAccount() { + bank.transfer(0, 1, 1000); + int[] accounts = bank.getAccounts(); + assertEquals(0, accounts[0]); + assertEquals(2000, accounts[1]); + } + + @Test + void BalanceHaveToBeOK() { + assertEquals(4000, bank.getBalance()); + } +} diff --git a/monitor/src/test/java/com/iluwatar/monitor/MainTest.java b/monitor/src/test/java/com/iluwatar/monitor/MainTest.java new file mode 100644 index 000000000000..75a313519fdc --- /dev/null +++ b/monitor/src/test/java/com/iluwatar/monitor/MainTest.java @@ -0,0 +1,42 @@ +/* + *The MIT License + *Copyright © 2014-2021 Ilkka Seppälä + * + *Permission is hereby granted, free of charge, to any person obtaining a copy + *of this software and associated documentation files (the "Software"), to deal + *in the Software without restriction, including without limitation the rights + *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + *copies of the Software, and to permit persons to whom the Software is + *furnished to do so, subject to the following conditions: + * + *The above copyright notice and this permission notice shall be included in + *all copies or substantial portions of the Software. + * + *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + *THE SOFTWARE. + */ + +package com.iluwatar.monitor; + +import org.junit.jupiter.api.Test; +import static org.junit.jupiter.api.Assertions.*; + +/** Test if the application starts without throwing an exception. */ +class MainTest { + + @Test + void shouldExecuteApplicationWithoutException() { + assertDoesNotThrow(() -> Main.main(new String[] {})); + } + + @Test + void RunnerExecuteWithoutException() { + var bank = new Bank(4, 1000); + assertDoesNotThrow(() -> Main.runner(bank)); + } +}

test

train

iluwatar

train

iluwatar/java-design-patterns/1299_1978

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1299

iluwatar/java-design-patterns/1978

4cdc309e65f3a1eae597ecb3b22e5ad6b7abbd41

f6a8e26f620322de21e0bf3c0cb7bb2c0719c191

Identity Map pattern

https://www.sourcecodeexamples.net/2018/04/identity-map-pattern.html https://en.wikipedia.org/wiki/Identity_map_pattern

diff --git a/identity-field/README.md b/identity-field/README.md new file mode 100644 index 000000000000..055d6a685b39 --- /dev/null +++ b/identity-field/README.md @@ -0,0 +1,64 @@ +--- +layout: pattern +title: Identity-Field +folder: identity-field +permalink: /patterns/identity-fields/ +categories: Structural +tags: +- Data access +--- + +## Intent +Saves a database ID field in an object to maintain an identity between an in-memory object and a database row. + +## Explanation + +In plain words + +> It uses a java class that has one field matching the primary key in a database table. + +**Programmatic Example** + +We have a **person** table which contains **id**, **name**, **age**, and **gender** as columns. + +| id | name | age | gender | +| :--------: | :--------: | :--------: | :--------: | +| 1 | ramesh | 28 | male | +| 2 | prakash | 28 | male | + +We also have a java class **Person** which contains **id**, **name**, **age**, and **gender** as fields. + +```java +class Person{ + private long id; + private String name; + private int age; + private String gender; + // standard getter and setter methods. +} +``` +1. **id** column is the **primary key** in a database that is unique and distinguishes each row. +2. In the above table, there are two rows and which are uniquely identified by the primary key. +3. The relational database uses the primary key to identify one row from another. + +The **id** column with datatype long represents the identity field. + +In **Person** java class, the **id** field is an identity field that matches the primary key in a database table. + +##Representing the Identity Field in an Object + +The simplest form of Identity Field is a field that matches the type of key in the database. Thus, if you use a simple integral key, an integral field will work very nicely. + +There are three basic choices to get the key: +- Get the database to auto-generate +- Use a GUID +- Generate your own + +## Class diagram + + +## Applicability +Use the Identity-Field pattern when + +* There’s a mapping between objects in memory and rows in a database. + \ No newline at end of file diff --git a/identity-field/etc/identity-field.puml b/identity-field/etc/identity-field.puml new file mode 100644 index 000000000000..c223331f93c9 --- /dev/null +++ b/identity-field/etc/identity-field.puml @@ -0,0 +1,17 @@ +@startuml +package com.iluwatar.identityfield { + class App { + + App() + + main(args : String[]) {static} + } + class Person { + - id : long + - name : string + + Person(id : long, name:string) + + getName():string + + setName(name:string) + + getId() : long + + setId(id:long) + } +} +@enduml \ No newline at end of file diff --git a/identity-field/pom.xml b/identity-field/pom.xml new file mode 100644 index 000000000000..e028dfeebdee --- /dev/null +++ b/identity-field/pom.xml @@ -0,0 +1,65 @@ +<?xml version="1.0" encoding="UTF-8"?> +<project xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <parent> + <artifactId>java-design-patterns</artifactId> + <groupId>com.iluwatar</groupId> + <version>1.26.0-SNAPSHOT</version> + </parent> + <modelVersion>4.0.0</modelVersion> + + <artifactId>identity-field</artifactId> + + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.mockito</groupId> + <artifactId>mockito-core</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.projectlombok</groupId> + <artifactId>lombok</artifactId> + <version>1.18.22</version> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <artifactId>maven-assembly-plugin</artifactId> + <configuration> + <archive> + <manifest> + <mainClass>com.test.MainClassName</mainClass> + </manifest> + </archive> + <descriptorRefs> + <descriptorRef>jar-with-dependencies</descriptorRef> + </descriptorRefs> + </configuration> + <executions> + <execution> + <id>make-assembly</id> + <phase>package</phase> <!-- packaging phase --> + <goals> + <goal>single</goal> + </goals> + </execution> + </executions> + </plugin> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-compiler-plugin</artifactId> + <configuration> + <source>8</source> + <target>8</target> + </configuration> + </plugin> + </plugins> + </build> +</project> \ No newline at end of file diff --git a/identity-field/src/main/java/com/iluwatar/identityfield/App.java b/identity-field/src/main/java/com/iluwatar/identityfield/App.java new file mode 100644 index 000000000000..4d97c029b001 --- /dev/null +++ b/identity-field/src/main/java/com/iluwatar/identityfield/App.java @@ -0,0 +1,63 @@ +/* + * The MIT License + * Copyright © 2014-2021 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.identityfield; + +import java.util.LinkedList; +import lombok.extern.slf4j.Slf4j; +import lombok.var; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * The identity field pattern is used to save a database ID field in an object + * to maintain an identity between an in-memory object and a database row. + * + * <p>In this example, the {@link Person} is used to save each row in the database in a java object. + * It uses the field id to identify the row in the database. + */ +@Slf4j +public class App { + + private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + /** + * The entry point of application. + * + * @param args the input arguments 、 + */ + + public static void main(String[] args) { + var pearsonList = new LinkedList<Person>(); + for (var i = 0; i < 5; i++) { + var name = "pearson" + i; + var person = new Person(i, name, i, "male"); + pearsonList.add(person); + } + for (var i = 0; i < 5; i++) { + LOGGER.info("Id: " + pearsonList.get(i).getId() + + " Name: " + pearsonList.get(i).getName() + + " Age: " + pearsonList.get(i).getAge() + + " Gender: " + pearsonList.get(i).getGender()); + } + } +} \ No newline at end of file diff --git a/identity-field/src/main/java/com/iluwatar/identityfield/Person.java b/identity-field/src/main/java/com/iluwatar/identityfield/Person.java new file mode 100644 index 000000000000..b5eafd583e22 --- /dev/null +++ b/identity-field/src/main/java/com/iluwatar/identityfield/Person.java @@ -0,0 +1,54 @@ +/* + * The MIT License + * Copyright © 2014-2021 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.identityfield; + +import lombok.Getter; +import lombok.Setter; + +/** + * Person is the class to store each row of the table in the database. + */ + +public class Person { + @Getter @Setter private long id; + @Getter @Setter private String name; + @Getter @Setter private int age; + @Getter @Setter private String gender; + + /** + * Instantiates a new Pearson. + * + * @param id the id of the person + * @param name the name of the person + * @param age the age of the person + * @param gender the gender of the person + */ + public Person(long id, String name, int age, String gender) { + this.id = id; + this.name = name; + this.age = age; + this.gender = gender; + } + +} \ No newline at end of file diff --git a/pom.xml b/pom.xml index 064e7c1a7eff..b1a503bdac77 100644 --- a/pom.xml +++ b/pom.xml @@ -231,6 +231,7 @@ <module>domain-model</module> <module>composite-view</module> <module>metadata-mapping</module> + <module>identity-field</module> </modules> <repositories> <repository>

diff --git a/identity-field/src/test/java/com/iluwatar/identityfield/AppTest.java b/identity-field/src/test/java/com/iluwatar/identityfield/AppTest.java new file mode 100644 index 000000000000..955618df68c9 --- /dev/null +++ b/identity-field/src/test/java/com/iluwatar/identityfield/AppTest.java @@ -0,0 +1,41 @@ +/* + * The MIT License + * Copyright © 2014-2021 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.identityfield; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +import org.junit.jupiter.api.Test; + +/** + * The type App test. + */ +class AppTest { + /** + * App test. + */ + @Test + void shouldExecuteWithoutException() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} \ No newline at end of file diff --git a/identity-field/src/test/java/com/iluwatar/identityfield/PersonTest.java b/identity-field/src/test/java/com/iluwatar/identityfield/PersonTest.java new file mode 100644 index 000000000000..70d80bbd5d7e --- /dev/null +++ b/identity-field/src/test/java/com/iluwatar/identityfield/PersonTest.java @@ -0,0 +1,89 @@ +/* + * The MIT License + * Copyright © 2014-2021 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.identityfield; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import lombok.var; +import org.junit.jupiter.api.Test; + +/** + * The type Pearson test. + */ +class PersonTest { + /** + * Pearson test. + */ + @Test + void setNameTest() { + var person = new Person(1, "ramesh", 28, "male"); + assertEquals(1, person.getId()); + assertEquals("ramesh", person.getName()); + assertEquals(28, person.getAge()); + assertEquals("male", person.getGender()); + var name = "prakash"; + person.setName(name); + assertEquals("prakash", person.getName()); + assertEquals(1, person.getId()); + } + + @Test + void setAgeTest() { + var person = new Person(1, "ramesh", 28, "male"); + assertEquals(1, person.getId()); + assertEquals("ramesh", person.getName()); + assertEquals(28, person.getAge()); + assertEquals("male", person.getGender()); + var age = 29; + person.setAge(age); + assertEquals(29, person.getAge()); + assertEquals(1, person.getId()); + } + + @Test + void setGenderTest() { + var person = new Person(1, "ramesh", 28, "male"); + assertEquals(1, person.getId()); + assertEquals("ramesh", person.getName()); + assertEquals(28, person.getAge()); + assertEquals("male", person.getGender()); + var gender = "female"; + person.setGender(gender); + assertEquals("female", person.getGender()); + assertEquals(1, person.getId()); + } + + @Test + void setIdTest() { + var person = new Person(1, "ramesh", 28, "male"); + assertEquals(1, person.getId()); + assertEquals("ramesh", person.getName()); + assertEquals(28, person.getAge()); + assertEquals("male", person.getGender()); + var id = 10; + person.setId(id); + assertEquals("ramesh", person.getName()); + assertEquals(10, person.getId()); + } +} \ No newline at end of file

train

train

iluwatar

train

iluwatar/java-design-patterns/1957_1994

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1957

iluwatar/java-design-patterns/1994

4cdc309e65f3a1eae597ecb3b22e5ad6b7abbd41

a143af638c04cf8797e9788d1d66111d7bfe35f1

Casting Issue


diff --git a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DefaultCircuitBreaker.java b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DefaultCircuitBreaker.java index 2194d75cbd2a..8c59f394bee1 100644 --- a/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DefaultCircuitBreaker.java +++ b/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DefaultCircuitBreaker.java @@ -38,7 +38,7 @@ public class DefaultCircuitBreaker implements CircuitBreaker { int failureCount; private final int failureThreshold; private State state; - private final long futureTime = 1000 * 1000 * 1000 * 1000; + private final long futureTime = 1000L * 1000 * 1000 * 1000; /** * Constructor to create an instance of Circuit Breaker.

train

train

MaheshMadushan

train

iluwatar/java-design-patterns/1968_2023

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1968

iluwatar/java-design-patterns/2023

5edcb2341c67feb003c5a5510fc4e6a0c6dcecb6

a568656036a135492bfe35ba767b77e52e9d3019

Visitor pattern code example violate SOLID

In the current example of the Visitor patter the `UnitVisitor` described as follow: ```java public interface UnitVisitor { void visitSoldier(Soldier soldier); void visitSergeant(Sergeant sergeant); void visitCommander(Commander commander); } ``` This interface violate the interface segregation principle as shown later on when implementing `CommanderVisitor`, `SergeantVisitor` and `SoldierVisitor` as each one of them have methods that are not relevant for the instance. The problem becomes even worst if someone will call be mistake the wrong method in the Unit concrete instances. For example: ```java public class Soldier extends Unit { public Soldier(Unit... children) { super(children); } @Override public void accept(UnitVisitor visitor) { visitor.visitCommander(this); // <-- Wrongly calling the commander method super.accept(visitor); } @Override public String toString() { return "soldier"; } } ``` This should be fixed by having a single method in the `UnitVisitor` interface as follow: ```java public interface Visitor { void visit(Unit unit); } ``` Or alternatively if you want to make sure that you're type safe: ```java public interface Visitor<T extends Unit> { void visit(T t); } ```

diff --git a/visitor/README.md b/visitor/README.md index 38df87d284cc..dae82966bf0f 100644 --- a/visitor/README.md +++ b/visitor/README.md @@ -72,7 +72,7 @@ public class Commander extends Unit { @Override public void accept(UnitVisitor visitor) { - visitor.visitCommander(this); + visitor.visit(this); super.accept(visitor); } @@ -90,7 +90,7 @@ public class Sergeant extends Unit { @Override public void accept(UnitVisitor visitor) { - visitor.visitSergeant(this); + visitor.visit(this); super.accept(visitor); } @@ -108,7 +108,7 @@ public class Soldier extends Unit { @Override public void accept(UnitVisitor visitor) { - visitor.visitSoldier(this); + visitor.visit(this); super.accept(visitor); } @@ -126,17 +126,17 @@ Here are then some concrete visitors. public class CommanderVisitor implements UnitVisitor { @Override - public void visitSoldier(Soldier soldier) { + public void visit(Soldier soldier) { // Do nothing } @Override - public void visitSergeant(Sergeant sergeant) { + public void visit(Sergeant sergeant) { // Do nothing } @Override - public void visitCommander(Commander commander) { + public void visit(Commander commander) { LOGGER.info("Good to see you {}", commander); } } @@ -145,17 +145,17 @@ public class CommanderVisitor implements UnitVisitor { public class SergeantVisitor implements UnitVisitor { @Override - public void visitSoldier(Soldier soldier) { + public void visit(Soldier soldier) { // Do nothing } @Override - public void visitSergeant(Sergeant sergeant) { + public void visit(Sergeant sergeant) { LOGGER.info("Hello {}", sergeant); } @Override - public void visitCommander(Commander commander) { + public void visit(Commander commander) { // Do nothing } } @@ -164,17 +164,17 @@ public class SergeantVisitor implements UnitVisitor { public class SoldierVisitor implements UnitVisitor { @Override - public void visitSoldier(Soldier soldier) { + public void visit(Soldier soldier) { LOGGER.info("Greetings {}", soldier); } @Override - public void visitSergeant(Sergeant sergeant) { + public void visit(Sergeant sergeant) { // Do nothing } @Override - public void visitCommander(Commander commander) { + public void visit(Commander commander) { // Do nothing } } diff --git a/visitor/src/main/java/com/iluwatar/visitor/Commander.java b/visitor/src/main/java/com/iluwatar/visitor/Commander.java index a7c0a0252ad2..9fd10dcd4b77 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/Commander.java +++ b/visitor/src/main/java/com/iluwatar/visitor/Commander.java @@ -32,9 +32,13 @@ public Commander(Unit... children) { super(children); } + /** + * Accept a Visitor. + * @param visitor UnitVisitor to be accepted + */ @Override public void accept(UnitVisitor visitor) { - visitor.visitCommander(this); + visitor.visit(this); super.accept(visitor); } diff --git a/visitor/src/main/java/com/iluwatar/visitor/CommanderVisitor.java b/visitor/src/main/java/com/iluwatar/visitor/CommanderVisitor.java index cf91623bf2b1..f26a4154aada 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/CommanderVisitor.java +++ b/visitor/src/main/java/com/iluwatar/visitor/CommanderVisitor.java @@ -31,18 +31,30 @@ @Slf4j public class CommanderVisitor implements UnitVisitor { + /** + * Soldier Visitor method. + * @param soldier Soldier to be visited + */ @Override - public void visitSoldier(Soldier soldier) { + public void visit(Soldier soldier) { // Do nothing } + /** + * Sergeant Visitor method. + * @param sergeant Sergeant to be visited + */ @Override - public void visitSergeant(Sergeant sergeant) { + public void visit(Sergeant sergeant) { // Do nothing } + /** + * Commander Visitor method. + * @param commander Commander to be visited + */ @Override - public void visitCommander(Commander commander) { + public void visit(Commander commander) { LOGGER.info("Good to see you {}", commander); } } diff --git a/visitor/src/main/java/com/iluwatar/visitor/Sergeant.java b/visitor/src/main/java/com/iluwatar/visitor/Sergeant.java index d92cfce3fcc5..96d1531be506 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/Sergeant.java +++ b/visitor/src/main/java/com/iluwatar/visitor/Sergeant.java @@ -32,9 +32,13 @@ public Sergeant(Unit... children) { super(children); } + /** + * Accept a Visitor. + * @param visitor UnitVisitor to be accepted + */ @Override public void accept(UnitVisitor visitor) { - visitor.visitSergeant(this); + visitor.visit(this); super.accept(visitor); } diff --git a/visitor/src/main/java/com/iluwatar/visitor/SergeantVisitor.java b/visitor/src/main/java/com/iluwatar/visitor/SergeantVisitor.java index f4bf23d5abc2..66fe05f129d6 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/SergeantVisitor.java +++ b/visitor/src/main/java/com/iluwatar/visitor/SergeantVisitor.java @@ -31,18 +31,30 @@ @Slf4j public class SergeantVisitor implements UnitVisitor { + /** + * Soldier Visitor method. + * @param soldier Soldier to be visited + */ @Override - public void visitSoldier(Soldier soldier) { + public void visit(Soldier soldier) { // Do nothing } + /** + * Sergeant Visitor method. + * @param sergeant Sergeant to be visited + */ @Override - public void visitSergeant(Sergeant sergeant) { + public void visit(Sergeant sergeant) { LOGGER.info("Hello {}", sergeant); } + /** + * Commander Visitor method. + * @param commander Commander to be visited + */ @Override - public void visitCommander(Commander commander) { + public void visit(Commander commander) { // Do nothing } } diff --git a/visitor/src/main/java/com/iluwatar/visitor/Soldier.java b/visitor/src/main/java/com/iluwatar/visitor/Soldier.java index ae27bd9c5555..ef7645891519 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/Soldier.java +++ b/visitor/src/main/java/com/iluwatar/visitor/Soldier.java @@ -32,9 +32,13 @@ public Soldier(Unit... children) { super(children); } + /** + * Accept a Visitor. + * @param visitor UnitVisitor to be accepted + */ @Override public void accept(UnitVisitor visitor) { - visitor.visitSoldier(this); + visitor.visit(this); super.accept(visitor); } diff --git a/visitor/src/main/java/com/iluwatar/visitor/SoldierVisitor.java b/visitor/src/main/java/com/iluwatar/visitor/SoldierVisitor.java index eb931e23858d..2ed8b66b980d 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/SoldierVisitor.java +++ b/visitor/src/main/java/com/iluwatar/visitor/SoldierVisitor.java @@ -31,18 +31,30 @@ @Slf4j public class SoldierVisitor implements UnitVisitor { + /** + * Soldier Visitor method. + * @param soldier Soldier to be visited + */ @Override - public void visitSoldier(Soldier soldier) { + public void visit(Soldier soldier) { LOGGER.info("Greetings {}", soldier); } + /** + * Sergeant Visitor method. + * @param sergeant Sergeant to be visited + */ @Override - public void visitSergeant(Sergeant sergeant) { + public void visit(Sergeant sergeant) { // Do nothing } + /** + * Commander Visitor method. + * @param commander Commander to be visited + */ @Override - public void visitCommander(Commander commander) { + public void visit(Commander commander) { // Do nothing } } diff --git a/visitor/src/main/java/com/iluwatar/visitor/UnitVisitor.java b/visitor/src/main/java/com/iluwatar/visitor/UnitVisitor.java index 29aefc1adbbf..08cce7babca8 100644 --- a/visitor/src/main/java/com/iluwatar/visitor/UnitVisitor.java +++ b/visitor/src/main/java/com/iluwatar/visitor/UnitVisitor.java @@ -28,10 +28,10 @@ */ public interface UnitVisitor { - void visitSoldier(Soldier soldier); + void visit(Soldier soldier); - void visitSergeant(Sergeant sergeant); + void visit(Sergeant sergeant); - void visitCommander(Commander commander); + void visit(Commander commander); }

diff --git a/visitor/src/test/java/com/iluwatar/visitor/CommanderTest.java b/visitor/src/test/java/com/iluwatar/visitor/CommanderTest.java index 1e68955509f5..a6054f7244f3 100644 --- a/visitor/src/test/java/com/iluwatar/visitor/CommanderTest.java +++ b/visitor/src/test/java/com/iluwatar/visitor/CommanderTest.java @@ -42,7 +42,7 @@ public CommanderTest() { @Override void verifyVisit(Commander unit, UnitVisitor mockedVisitor) { - verify(mockedVisitor).visitCommander(eq(unit)); + verify(mockedVisitor).visit(eq(unit)); } } \ No newline at end of file diff --git a/visitor/src/test/java/com/iluwatar/visitor/SergeantTest.java b/visitor/src/test/java/com/iluwatar/visitor/SergeantTest.java index 77fcbafe6a52..4d430f5beedb 100644 --- a/visitor/src/test/java/com/iluwatar/visitor/SergeantTest.java +++ b/visitor/src/test/java/com/iluwatar/visitor/SergeantTest.java @@ -42,7 +42,7 @@ public SergeantTest() { @Override void verifyVisit(Sergeant unit, UnitVisitor mockedVisitor) { - verify(mockedVisitor).visitSergeant(eq(unit)); + verify(mockedVisitor).visit(eq(unit)); } } \ No newline at end of file diff --git a/visitor/src/test/java/com/iluwatar/visitor/SoldierTest.java b/visitor/src/test/java/com/iluwatar/visitor/SoldierTest.java index a59eca6b450d..f5f31767ee9a 100644 --- a/visitor/src/test/java/com/iluwatar/visitor/SoldierTest.java +++ b/visitor/src/test/java/com/iluwatar/visitor/SoldierTest.java @@ -42,7 +42,7 @@ public SoldierTest() { @Override void verifyVisit(Soldier unit, UnitVisitor mockedVisitor) { - verify(mockedVisitor).visitSoldier(eq(unit)); + verify(mockedVisitor).visit(eq(unit)); } } \ No newline at end of file diff --git a/visitor/src/test/java/com/iluwatar/visitor/VisitorTest.java b/visitor/src/test/java/com/iluwatar/visitor/VisitorTest.java index 694be7ab23f8..dbc342806685 100644 --- a/visitor/src/test/java/com/iluwatar/visitor/VisitorTest.java +++ b/visitor/src/test/java/com/iluwatar/visitor/VisitorTest.java @@ -97,7 +97,7 @@ public VisitorTest( @Test void testVisitCommander() { - this.visitor.visitCommander(new Commander()); + this.visitor.visit(new Commander()); if (this.commanderResponse.isPresent()) { assertEquals(this.commanderResponse.get(), appender.getLastMessage()); assertEquals(1, appender.getLogSize()); @@ -106,7 +106,7 @@ void testVisitCommander() { @Test void testVisitSergeant() { - this.visitor.visitSergeant(new Sergeant()); + this.visitor.visit(new Sergeant()); if (this.sergeantResponse.isPresent()) { assertEquals(this.sergeantResponse.get(), appender.getLastMessage()); assertEquals(1, appender.getLogSize()); @@ -115,7 +115,7 @@ void testVisitSergeant() { @Test void testVisitSoldier() { - this.visitor.visitSoldier(new Soldier()); + this.visitor.visit(new Soldier()); if (this.soldierResponse.isPresent()) { assertEquals(this.soldierResponse.get(), appender.getLastMessage()); assertEquals(1, appender.getLogSize());

train

train

yonatankarp

train

iluwatar/java-design-patterns/2034_2038

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2034

iluwatar/java-design-patterns/2038

7e87cf9005edea0cedb354e305598eb3feb18f65

57fe447f9c0f0ca07a65adafdadcae808d2be344

Upgrade Lombok version to support Java 17

This issue is a part of the Java 17 transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. According to https://github.com/projectlombok/lombok/issues/2898, Lombok supports Java 17 since version 1.18.22. Our version is a bit behind that, so let's upgrade to the latest. Acceptance criteria - Lombok version has been updated to the latest available

diff --git a/pom.xml b/pom.xml index a9477de828d8..3e02bfd45eb2 100644 --- a/pom.xml +++ b/pom.xml @@ -66,7 +66,7 @@ <system-lambda.version>1.1.0</system-lambda.version> <urm.version>2.0.0</urm.version> <mockito-junit-jupiter.version>3.5.0</mockito-junit-jupiter.version> - <lombok.version>1.18.20</lombok.version> + <lombok.version>1.18.22</lombok.version> <byte-buddy.version>1.11.5</byte-buddy.version> <javassist.version>3.27.0-GA</javassist.version> <maven-surefire-plugin.version>3.0.0-M5</maven-surefire-plugin.version>

train

train

iluwatar

train

iluwatar/java-design-patterns/2045_2046

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2045

iluwatar/java-design-patterns/2046

7e87cf9005edea0cedb354e305598eb3feb18f65

84f733d137313af6f9bf1847fa140b07ea390d1f

Translate abstract-document readme to Spanish

I'll translate the readme file of the abstract-document design pattern to Spanish and place it under localization.es.abstract-document.

diff --git a/localization/es/abstract-document/README.md b/localization/es/abstract-document/README.md new file mode 100644 index 000000000000..f9b698b939cc --- /dev/null +++ b/localization/es/abstract-document/README.md @@ -0,0 +1,183 @@ +--- +layout: pattern +title: Abstract Document +folder: abstract-document +permalink: /patterns/abstract-document/ +categories: Structural +language: es +tags: + - Extensibility +--- + +## Propósito + +Usar propiedades dinámicas y conseguir la felexibilidad de los lenguajes no tipados manteniendo la seguridad de tipos. + +## Explicación + +El uso del patrón Abstract Document permite gestionar propiedades no estáticas adicionales. Este patrón usa el concepto de atributos para permitir seguridad de tipos y propiedades separadas de diferentes clases en un grupo de interfaces. + +Ejemplo del mundo real + +> Toma como ejemplo un coche que está formado por muchas partes. Sin embargo, no sabemos si el coche tiene todas las partes o solo una parte de ellas. Nuestros coches son dinámicos y extremadamente flexibles. + +En resumen + +> El patrón Abstract Document permite añadir propiedades a objetos sin que estos sean conscientes de ello. + +Según Wikipedia + +> Un patrón de diseño estructural orientado a objetos para organizar objetos en contenedores clave-valor vagamente tipados y exponiendo los datos usando vistas tipadas. El propósito del patrón es conseguir un alto grado de flexibilidad entre componentes en un lenguaje de tipado fuerte donde nuevas propiedades pueden añadirse al arbol de objetos sobre la marcha sin perder el soporte de la seguridad de tipos. El patrón hace uso de atributos para separar diferentes propiedades de una clase en distintas interfaces. + +**Ejemplo Programático** + +Primero definamos las clases base `Document` y `AbstractDocument`. Básicamente hacen que el objeto contenga un mapa de propiedades y cualquier número de objetos hijo. + +```java +public interface Document { + + Void put(String key, Object value); + + Object get(String key); + + <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor); +} + +public abstract class AbstractDocument implements Document { + + private final Map<String, Object> properties; + + protected AbstractDocument(Map<String, Object> properties) { + Objects.requireNonNull(properties, "properties map is required"); + this.properties = properties; + } + + @Override + public Void put(String key, Object value) { + properties.put(key, value); + return null; + } + + @Override + public Object get(String key) { + return properties.get(key); + } + + @Override + public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) { + return Stream.ofNullable(get(key)) + .filter(Objects::nonNull) + .map(el -> (List<Map<String, Object>>) el) + .findAny() + .stream() + .flatMap(Collection::stream) + .map(constructor); + } + ... +} +``` +A continuación definimos un enum `Property` y un grupo de interfaces para tipo, precio, modelo y partes. Esto nos permite crear interfaces de apariencia estática para nuestra clase `Car`. + +```java +public enum Property { + + PARTS, TYPE, PRICE, MODEL +} + +public interface HasType extends Document { + + default Optional<String> getType() { + return Optional.ofNullable((String) get(Property.TYPE.toString())); + } +} + +public interface HasPrice extends Document { + + default Optional<Number> getPrice() { + return Optional.ofNullable((Number) get(Property.PRICE.toString())); + } +} +public interface HasModel extends Document { + + default Optional<String> getModel() { + return Optional.ofNullable((String) get(Property.MODEL.toString())); + } +} + +public interface HasParts extends Document { + + default Stream<Part> getParts() { + return children(Property.PARTS.toString(), Part::new); + } +} +``` + +Ahora estamos listos para introducir el Coche `Car`. + +```java +public class Car extends AbstractDocument implements HasModel, HasPrice, HasParts { + + public Car(Map<String, Object> properties) { + super(properties); + } +} +``` + +Y finalmente asi es como construimos y usamos el Coche `Car` en un ejemplo completo. + +```java + LOGGER.info("Constructing parts and car"); + + var wheelProperties = Map.of( + Property.TYPE.toString(), "wheel", + Property.MODEL.toString(), "15C", + Property.PRICE.toString(), 100L); + + var doorProperties = Map.of( + Property.TYPE.toString(), "door", + Property.MODEL.toString(), "Lambo", + Property.PRICE.toString(), 300L); + + var carProperties = Map.of( + Property.MODEL.toString(), "300SL", + Property.PRICE.toString(), 10000L, + Property.PARTS.toString(), List.of(wheelProperties, doorProperties)); + + var car = new Car(carProperties); + + LOGGER.info("Here is our car:"); + LOGGER.info("-> model: {}", car.getModel().orElseThrow()); + LOGGER.info("-> price: {}", car.getPrice().orElseThrow()); + LOGGER.info("-> parts: "); + car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}", + p.getType().orElse(null), + p.getModel().orElse(null), + p.getPrice().orElse(null)) + ); + + // Constructing parts and car + // Here is our car: + // model: 300SL + // price: 10000 + // parts: + // wheel/15C/100 + // door/Lambo/300 +``` + +## Diagrama de clases + + + +## Aplicación + +Usar el patrón Abstract Document cuando + +* Existe la necesidad de añadir propiedades sobre la marcha. +* Quieres una manera flexible de organizar el dominio en una estructura similar a un arbol. +* Quieres un sistema menos acoplado. + +## Créditos + +* [Wikipedia: Abstract Document Pattern](https://en.wikipedia.org/wiki/Abstract_Document_Pattern) +* [Martin Fowler: Dealing with properties](http://martinfowler.com/apsupp/properties.pdf) +* [Pattern-Oriented Software Architecture Volume 4: A Pattern Language for Distributed Computing (v. 4)](https://www.amazon.com/gp/product/0470059028/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=0470059028&linkId=e3aacaea7017258acf184f9f3283b492)

train

train

aitorfi

train

iluwatar/java-design-patterns/1099_2057

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1099

iluwatar/java-design-patterns/2057

4c1f5cf7fe8cf4ecd427fb5603158bbe17a51406

67f01d43aaa06a8b1191e55665f3fa5b6805c1c9

Template Method

As statet in the referenced tutorial [Template-method Pattern Tutorial](https://www.journaldev.com/1763/template-method-design-pattern-in-java) I would add a note in the pattern description that the template method should be declared `final`. > To make sure that subclasses don’t override the template method, we should make it final. And I would change the code accordingly.

diff --git a/template-method/README.md b/template-method/README.md index 7209176f2255..ba34441e0ca8 100644 --- a/template-method/README.md +++ b/template-method/README.md @@ -39,6 +39,10 @@ Wikipedia says **Programmatic Example** Let's first introduce the template method class along with its concrete implementations. +To make sure that subclasses don’t override the template method, the template method (in our case +method `steal`) should be declared `final`, otherwise the skeleton defined in the base class could +be overridden in subclasses. + ```java @Slf4j @@ -50,7 +54,7 @@ public abstract class StealingMethod { protected abstract void stealTheItem(String target); - public void steal() { + public final void steal() { var target = pickTarget(); LOGGER.info("The target has been chosen as {}.", target); confuseTarget(target); diff --git a/template-method/pom.xml b/template-method/pom.xml index ec791eae4c55..dc75fdef0212 100644 --- a/template-method/pom.xml +++ b/template-method/pom.xml @@ -41,7 +41,7 @@ </dependency> <dependency> <groupId>org.mockito</groupId> - <artifactId>mockito-core</artifactId> + <artifactId>mockito-inline</artifactId> <scope>test</scope> </dependency> </dependencies> diff --git a/template-method/src/main/java/com/iluwatar/templatemethod/StealingMethod.java b/template-method/src/main/java/com/iluwatar/templatemethod/StealingMethod.java index ea4248548db2..db8813fa2bb9 100644 --- a/template-method/src/main/java/com/iluwatar/templatemethod/StealingMethod.java +++ b/template-method/src/main/java/com/iluwatar/templatemethod/StealingMethod.java @@ -41,7 +41,7 @@ public abstract class StealingMethod { /** * Steal. */ - public void steal() { + public final void steal() { var target = pickTarget(); LOGGER.info("The target has been chosen as {}.", target); confuseTarget(target);

diff --git a/template-method/src/test/java/com/iluwatar/templatemethod/HalflingThiefTest.java b/template-method/src/test/java/com/iluwatar/templatemethod/HalflingThiefTest.java index eaf7699acffd..9f802597394e 100644 --- a/template-method/src/test/java/com/iluwatar/templatemethod/HalflingThiefTest.java +++ b/template-method/src/test/java/com/iluwatar/templatemethod/HalflingThiefTest.java @@ -24,7 +24,7 @@ */ package com.iluwatar.templatemethod; -import static org.mockito.Mockito.mock; +import static org.mockito.Mockito.spy; import static org.mockito.Mockito.verify; import static org.mockito.Mockito.verifyNoMoreInteractions; @@ -42,11 +42,14 @@ public class HalflingThiefTest { */ @Test void testSteal() { - final var method = mock(StealingMethod.class); + final var method = spy(StealingMethod.class); final var thief = new HalflingThief(method); thief.steal(); verify(method).steal(); + String target = verify(method).pickTarget(); + verify(method).confuseTarget(target); + verify(method).stealTheItem(target); verifyNoMoreInteractions(method); } @@ -56,19 +59,23 @@ void testSteal() { */ @Test void testChangeMethod() { - final var initialMethod = mock(StealingMethod.class); + final var initialMethod = spy(StealingMethod.class); final var thief = new HalflingThief(initialMethod); thief.steal(); verify(initialMethod).steal(); + String target = verify(initialMethod).pickTarget(); + verify(initialMethod).confuseTarget(target); + verify(initialMethod).stealTheItem(target); - final var newMethod = mock(StealingMethod.class); + final var newMethod = spy(StealingMethod.class); thief.changeMethod(newMethod); thief.steal(); verify(newMethod).steal(); - + String newTarget = verify(newMethod).pickTarget(); + verify(newMethod).confuseTarget(newTarget); + verify(newMethod).stealTheItem(newTarget); verifyNoMoreInteractions(initialMethod, newMethod); - } } \ No newline at end of file

train

val

dgruntz

train

iluwatar/java-design-patterns/2066_2072

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2066

iluwatar/java-design-patterns/2072

ec07dda65899c5bdcd079a6513e4138b6a96c1a5

d43b21472dfd18ca07ca9f9ec30c31ef0ab2af3c

Translate the abstract-factory readme to Spanish

I'll translate the readme file of the abstract-factory design pattern to Spanish and place it under localization.es.abstract-factory.

diff --git a/localization/es/abstract-document/README.md b/localization/es/abstract-document/README.md index f9b698b939cc..2baf94551b09 100644 --- a/localization/es/abstract-document/README.md +++ b/localization/es/abstract-document/README.md @@ -21,7 +21,7 @@ Ejemplo del mundo real > Toma como ejemplo un coche que está formado por muchas partes. Sin embargo, no sabemos si el coche tiene todas las partes o solo una parte de ellas. Nuestros coches son dinámicos y extremadamente flexibles. -En resumen +Dicho de otra forma > El patrón Abstract Document permite añadir propiedades a objetos sin que estos sean conscientes de ello. @@ -166,7 +166,7 @@ Y finalmente asi es como construimos y usamos el Coche `Car` en un ejemplo compl ## Diagrama de clases - + ## Aplicación diff --git a/localization/es/abstract-factory/README.md b/localization/es/abstract-factory/README.md new file mode 100644 index 000000000000..610b139a0235 --- /dev/null +++ b/localization/es/abstract-factory/README.md @@ -0,0 +1,234 @@ +--- +layout: pattern +title: Abstract Factory +folder: abstract-factory +permalink: /patterns/abstract-factory/ +categories: Creational +language: es +tags: + - Gang of Four +--- + +## También conocido como + +Kit + +## Propósito + +Proveer de una interfaz para crear familias de objetos relacionados dependientes sin especificar su clase concreta. + +## Explicación + +Ejemplo del mundo real + +> Para crear un reino necesitamos objetos con una temática común. El reino élfico necesita un rey elfo, un castillo élfico y un ejército élfico mientras que el reino orco necesita un rey orco, un castillo orco y un ejércico orco. Hay una dependencia entre los objetos del reino. + +Dicho de otra forma + +> Una factoría de factorías; una factoría que agrupa otras factorias individuales pero relacionadas/dependientes sin especificar su clase concreta. + +Según Wikipedia + +> El patrón abstract factory provee una forma de encapsular un grupo de factorías individuales que tienen una temática común sin especificar sus clases concretas. + +**Ejemplo Programático** + +Traduciendo el ejemplo anterior sobre los reinos. Primero tenemos algunas interfaces e implementaciones de los objetos del reino. + +```java +public interface Castle { + String getDescription(); +} + +public interface King { + String getDescription(); +} + +public interface Army { + String getDescription(); +} + +// Elven implementations -> +public class ElfCastle implements Castle { + static final String DESCRIPTION = "This is the elven castle!"; + @Override + public String getDescription() { + return DESCRIPTION; + } +} +public class ElfKing implements King { + static final String DESCRIPTION = "This is the elven king!"; + @Override + public String getDescription() { + return DESCRIPTION; + } +} +public class ElfArmy implements Army { + static final String DESCRIPTION = "This is the elven Army!"; + @Override + public String getDescription() { + return DESCRIPTION; + } +} + +// Orcish implementations similarly -> ... + +``` + +Luego tenemos la abstracción e implementación de la factoría del reino. + +```java +public interface KingdomFactory { + Castle createCastle(); + King createKing(); + Army createArmy(); +} + +public class ElfKingdomFactory implements KingdomFactory { + + @Override + public Castle createCastle() { + return new ElfCastle(); + } + + @Override + public King createKing() { + return new ElfKing(); + } + + @Override + public Army createArmy() { + return new ElfArmy(); + } +} + +public class OrcKingdomFactory implements KingdomFactory { + + @Override + public Castle createCastle() { + return new OrcCastle(); + } + + @Override + public King createKing() { + return new OrcKing(); + } + + @Override + public Army createArmy() { + return new OrcArmy(); + } +} +``` + +Ahora tenemos la factoría abstracta que nos permite hacer familias de objetos relacionados por ejemplo la factoria del reino élfico crea el castillo, rey y ejercito élficos etc. + + +```java +var factory = new ElfKingdomFactory(); +var castle = factory.createCastle(); +var king = factory.createKing(); +var army = factory.createArmy(); + +castle.getDescription(); +king.getDescription(); +army.getDescription(); +``` + +Output del programa: + +```java +This is the elven castle! +This is the elven king! +This is the elven Army! +``` + +Ahora podemos diseñar una factoría para nuestras factorías de reinos. En este ejemplo creamos `FactoryMaker`, responsable de devolver una instancia de `ElfKingdomFactory` o `OrcKingdomFactory`. +El cliente puede usar `FactoryMaker` para crear una factoría concreta, que a su vez, producirá diferentes objetos concretos (derivados de `Army`, `King`, `Castle`). +En este ejemplo también usamos un enum para parametrizar el tipo de factoría de reinos pedirá el cliente. + +```java +public static class FactoryMaker { + + public enum KingdomType { + ELF, ORC + } + + public static KingdomFactory makeFactory(KingdomType type) { + switch (type) { + case ELF: + return new ElfKingdomFactory(); + case ORC: + return new OrcKingdomFactory(); + default: + throw new IllegalArgumentException("KingdomType not supported."); + } + } +} + +public static void main(String[] args) { + var app = new App(); + + LOGGER.info("Elf Kingdom"); + app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF)); + LOGGER.info(app.getArmy().getDescription()); + LOGGER.info(app.getCastle().getDescription()); + LOGGER.info(app.getKing().getDescription()); + + LOGGER.info("Orc Kingdom"); + app.createKingdom(FactoryMaker.makeFactory(KingdomType.ORC)); + -- similar use of the orc factory +} +``` + +## Diagrama de clases + + + + +## Aplicación + +Usar el patrón Abstract Factory cuando + +* El sistema debe ser agnóstico a como se crean, componen y representan sus objetos. +* El sistema debe ser configurado con una de las múltiples familias de productos. +* La familia de objetos relacionados está diseñada para ser usada en conjunto y necesitas forzar esta premisa. +* Quieres proveer de una librería de productos y solo quieres revelar sus interfaces, no su implementación. +* El tiempo de vida de la dependencia es conceptualmente mas corte que el del cliente. +* Necesitas un valor en tiempo de ejecución para construir una dependencia. +* Quieres decidir que producto de una familia llamar en tiempo de ejecución. +* Necesitas proveer de uno o mas parámetros solo conocidos en tiempo de ejecución antes de poder resolver la dependencia. +* Necesitas consistencia entre productos. +* No quieres cambiar el código existente al añadir nuevos productos o familias de productos al programa. + +Ejemplos de casos de uso + +* Elegir llamar a la implementación correcta de FileSystemAcmeService o DatabaseAcmeService o NetworkAcmeService en tiempo de ejecución. +* Escribir test unitarios se hace mucho mas sencillo. +* Herramientas UI (User Interface) para diferentes SO (Sistemas Operativos). + +## Consecuencias + +* La inyección de dependencias en java esconde las dependencias de la clase servicio lo que puede llevar a errores de ejecución que se podrian haber evitado al compilar. +* Mientras que el patrón es muy bueno creando objetos predefinidos, añadir nuevos puede ser complicado. +* El código es mas complicado de lo que deberia porque se añaden muchas interfaces y clases nuevas junto con el patrón. + +## Tutoriales + +* [Abstract Factory Pattern Tutorial](https://www.journaldev.com/1418/abstract-factory-design-pattern-in-java) + +## Usos conocidos + +* [javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html) +* [javax.xml.transform.TransformerFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/transform/TransformerFactory.html#newInstance--) +* [javax.xml.xpath.XPathFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/xpath/XPathFactory.html#newInstance--) + +## Patrones relacionados + +* [Factory Method](https://java-design-patterns.com/patterns/factory-method/) +* [Factory Kit](https://java-design-patterns.com/patterns/factory-kit/) + +## Créditos + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)

val

val

aitorfi

train

iluwatar/java-design-patterns/2054_2073

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2054

iluwatar/java-design-patterns/2073

ec07dda65899c5bdcd079a6513e4138b6a96c1a5

09f97206a72f8e13a4da6b3d998bd94802afd43e

Sonar analysis failing due to obsolete Node version

This came up in a recent pull request build: > [ERROR] Failed to execute goal org.sonarsource.scanner.maven:sonar-maven-plugin:3.8.0.2131:sonar (default-cli) on project java-design-patterns: > [ERROR] > [ERROR] The version of node.js (12) you have used to run this analysis is deprecated and we stopped accepting it. > [ERROR] Please update to at least node.js 14. You can find more information here: https://docs.sonarcloud.io/appendices/scanner-environment/ Acceptance criteria - Node version used in the CI build has been upgraded to fix the Sonar analysis

diff --git a/.circleci/config.yml b/.circleci/config.yml index 3e35aee712dd..dad7997a8699 100644 --- a/.circleci/config.yml +++ b/.circleci/config.yml @@ -26,12 +26,14 @@ version: 2 jobs: sonar-pr: docker: - - image: circleci/openjdk:11-node + - image: cimg/openjdk:11.0-node steps: - checkout - restore_cache: key: jdp-sonar-pr-{{ checksum "pom.xml" }} - run: | + sudo apt-get update + sudo apt-get install -y openjdk-11-jdk xvfb if [ -n "${CIRCLE_PR_NUMBER}" ]; then MAVEN_OPTS="-Xmx3000m" xvfb-run ./mvnw -B clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \ -Dsonar.pullrequest.key=${CIRCLE_PR_NUMBER} \

train

val

iluwatar

train

iluwatar/java-design-patterns/2077_2078

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2077

iluwatar/java-design-patterns/2078

8a7c7b6f21200e33d724fff350c8449964d02c08

505454cbae5fbb58bfd2df51beb48b3307c4f6e6

Translate the active-object readme to Spanish

I'll translate the readme file of the active-object design pattern to Spanish and place it under localization.es.active-object.

diff --git a/localization/es/active-object/README.md b/localization/es/active-object/README.md new file mode 100644 index 000000000000..617d07b77eab --- /dev/null +++ b/localization/es/active-object/README.md @@ -0,0 +1,130 @@ +--- +layout: pattern +title: Active Object +folder: active-object +permalink: /patterns/active-object/ +categories: Concurrency +language: es +tags: + - Performance +--- + + +## Propósito +El patrón de diseño de objeto activo desacopla la ejecución del método de la invocación del método para los objetos que residen en su propio hilo de control. El objetivo es introducir la concurrencia mediante el uso de la invocación de métodos asíncronos y un planificador para manejar solicitudes. + +## Explicación + +La clase que implementa el patrón de diseño de objeto activo contendrá un mecanismo de autosincronización sin utilizar métodos sincronizados (synchronized). + +Ejemplo del mundo real + +> Los orcos son conocidos por su salvajismo y filosofía de no hacer equipo. Basandonos en este comportamiento se podría decir que tienen su propio hilo de control. + +Podemos usar el patrón Active Object para implementar una criatura que tiene su propio hilo de control y exponer su API pero no la ejecución como tal. + + +**Ejemplo Programático** + +```java +public abstract class ActiveCreature{ + private final Logger logger = LoggerFactory.getLogger(ActiveCreature.class.getName()); + + private BlockingQueue<Runnable> requests; + + private String name; + + private Thread thread; + + public ActiveCreature(String name) { + this.name = name; + this.requests = new LinkedBlockingQueue<Runnable>(); + thread = new Thread(new Runnable() { + @Override + public void run() { + while (true) { + try { + requests.take().run(); + } catch (InterruptedException e) { + logger.error(e.getMessage()); + } + } + } + } + ); + thread.start(); + } + + public void eat() throws InterruptedException { + requests.put(new Runnable() { + @Override + public void run() { + logger.info("{} is eating!",name()); + logger.info("{} has finished eating!",name()); + } + } + ); + } + + public void roam() throws InterruptedException { + requests.put(new Runnable() { + @Override + public void run() { + logger.info("{} has started to roam the wastelands.",name()); + } + } + ); + } + + public String name() { + return this.name; + } +} +``` + +Podemos ver que cualquier clase que extienda de ActiveCreature tendrá su propio hilo de control para invocar y ejecutar métodos. + +Por ejemplo, la clase Orc: + +```java +public class Orc extends ActiveCreature { + + public Orc(String name) { + super(name); + } + +} +``` + +Ahora podemos crear múltiples criaturas como los Orcos, diles que coman y deambulen y lo harán en su propio hilo de control: + +```java + public static void main(String[] args) { + var app = new App(); + app.run(); + } + + @Override + public void run() { + ActiveCreature creature; + try { + for (int i = 0;i < creatures;i++) { + creature = new Orc(Orc.class.getSimpleName().toString() + i); + creature.eat(); + creature.roam(); + } + Thread.sleep(1000); + } catch (InterruptedException e) { + logger.error(e.getMessage()); + } + Runtime.getRuntime().exit(1); + } +``` + +## Diagrama de clases + + + +## Tutoriales + +* [Android and Java Concurrency: The Active Object Pattern](https://www.youtube.com/watch?v=Cd8t2u5Qmvc) \ No newline at end of file

test

val

aitorfi

train

iluwatar/java-design-patterns/2089_2090

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2089

iluwatar/java-design-patterns/2090

1e232d855267274a0dd7b2d46ab11728015612b8

03feaa9faf7bb8de209b8fa72a8d3559629e6c64

Translate the acyclic-visitor readme to Spanish

I'll translate the readme file of the acyclic-visitor design pattern to Spanish and place it under localization.es.acyclic-visitor.

diff --git a/localization/es/acyclic-visitor/README.md b/localization/es/acyclic-visitor/README.md new file mode 100644 index 000000000000..08d016b80430 --- /dev/null +++ b/localization/es/acyclic-visitor/README.md @@ -0,0 +1,162 @@ +--- +layout: pattern +title: Acyclic Visitor +folder: acyclic-visitor +permalink: /patterns/acyclic-visitor/ +categories: Behavioral +language: es +tags: + - Extensibility +--- + +## Propósito + +Permitir añadir nuevas funciones a jerarquías de clases existentes sin que estas se vean afectadas, y sin crear los problemáticos círculos de dependencias que son inherentes al patrón GoF (Gang of Four) Visitor. + +## Explicación + +Ejemplo del mundo real + +> Tenemos una jerarquía de clases módem. Los modems de esta jerarquía deben ser visitados por un algoritmo externo basándose en unos filtros (el módem es compatible con Unix o DOS). + +En otras palabras + +> Acyclic Visitor permite añadir funciones a jerarquías de clases existentes sin modificarlas. + +[WikiWikiWeb](https://wiki.c2.com/?AcyclicVisitor) dice + +> El patrón Acyclic Visitor permite que nuevas funciones sean añadidas a jerarquías de clases existentes sin afectar a las mismas, y sin crear los círculos de dependencias que son inherentes al patrón Visitor Pattern de GangOfFour. + +**Ejemplo Programático** + +Aquí tenemos la jerarquía `Modem`. + +```java +public abstract class Modem { + public abstract void accept(ModemVisitor modemVisitor); +} + +public class Zoom extends Modem { + ... + @Override + public void accept(ModemVisitor modemVisitor) { + if (modemVisitor instanceof ZoomVisitor) { + ((ZoomVisitor) modemVisitor).visit(this); + } else { + LOGGER.info("Only ZoomVisitor is allowed to visit Zoom modem"); + } + } +} + +public class Hayes extends Modem { + ... + @Override + public void accept(ModemVisitor modemVisitor) { + if (modemVisitor instanceof HayesVisitor) { + ((HayesVisitor) modemVisitor).visit(this); + } else { + LOGGER.info("Only HayesVisitor is allowed to visit Hayes modem"); + } + } +} +``` + +Después tenemos la jerarquía `ModemVisitor`. + +```java +public interface ModemVisitor { +} + +public interface HayesVisitor extends ModemVisitor { + void visit(Hayes hayes); +} + +public interface ZoomVisitor extends ModemVisitor { + void visit(Zoom zoom); +} + +public interface AllModemVisitor extends ZoomVisitor, HayesVisitor { +} + +public class ConfigureForDosVisitor implements AllModemVisitor { + ... + @Override + public void visit(Hayes hayes) { + LOGGER.info(hayes + " used with Dos configurator."); + } + @Override + public void visit(Zoom zoom) { + LOGGER.info(zoom + " used with Dos configurator."); + } +} + +public class ConfigureForUnixVisitor implements ZoomVisitor { + ... + @Override + public void visit(Zoom zoom) { + LOGGER.info(zoom + " used with Unix configurator."); + } +} +``` + +Finalmente aquí están los "visitors" en acción. + +```java + var conUnix = new ConfigureForUnixVisitor(); + var conDos = new ConfigureForDosVisitor(); + var zoom = new Zoom(); + var hayes = new Hayes(); + hayes.accept(conDos); + zoom.accept(conDos); + hayes.accept(conUnix); + zoom.accept(conUnix); +``` + +Output del programa: + +``` + // Hayes modem used with Dos configurator. + // Zoom modem used with Dos configurator. + // Only HayesVisitor is allowed to visit Hayes modem + // Zoom modem used with Unix configurator. +``` + +## Diagrama de clases + + + +## Aplicación + +Este patrón puede ser usado: + +* Cuando necesitas añadir una nueva función a una jerarquía de clases sin que esta se vea afectada o alterada. +* Cuando hay funciones que operan sobre la jerarquía pero no pertenecen a la jerarquía como tal. Las clases ConfigureForDOS / ConfigureForUnix / ConfigureForX por ejemplo. +* Cuando necesitas ejecutar operaciones muy diferentes en un objeto dependiendo de su tipo. +* Cuando la jerarquía visitada va a ser frecuentemente extendida con derivados de la clase elemento. +* Cuando el proceso de volver a compilar, enlazar, probar o distribuir los derivados de la clase elemento es muy pesado. + +## Tutoriales + +* [Acyclic Visitor Pattern Example](https://codecrafter.blogspot.com/2012/12/the-acyclic-visitor-pattern.html) + +## Consecuencias + +Buenas: + +* No hay círculos de dependencias entre las jerarquías. +* No es necesario compilar todos los visitantes si se añade uno nuevo. +* No provoca errores de compilación en visitantes existentes si la jerarquía tiene un nuevo miembro. + +Malas: + +* Viola el [Principio de sustitución de Liskov](https://java-design-patterns.com/principles/#liskov-substitution-principle) al mostrar que puede aceptar todos los visitantes solamente estando interesado en uno en particular. +* Hay que crear una jerarquía de visitantes paralela para todos los miembros de una jerarquía visitable. + +## Patrones relacionados + +* [Visitor Pattern](https://java-design-patterns.com/patterns/visitor/) + +## Créditos + +* [Acyclic Visitor by Robert C. Martin](http://condor.depaul.edu/dmumaugh/OOT/Design-Principles/acv.pdf) +* [Acyclic Visitor in WikiWikiWeb](https://wiki.c2.com/?AcyclicVisitor)

val

val

aitorfi

train

iluwatar/java-design-patterns/2096_2099

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2096

iluwatar/java-design-patterns/2099

1e232d855267274a0dd7b2d46ab11728015612b8

250bb5be3fc351231b3f9ce93946706facf71082

Add lombok to data-transfer-object pattern

I noticed that the pattern is well written but is using a lot of getters and setters without need. We can add lombok to it and have it cleaner to read and understand

diff --git a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/App.java b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/App.java index 8a731303a664..e9164600ce7e 100644 --- a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/App.java +++ b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/App.java @@ -87,29 +87,29 @@ public static void main(String[] args) { printCustomerDetails(allCustomers); // Example 2: Product DTO - Product tv = - new Product().setId(1L).setName("TV").setSupplier("Sony").setPrice(1000D).setCost(1090D); + + Product tv = Product.builder().id(1L).name("TV").supplier("Sony").price(1000D).cost(1090D).build(); Product microwave = - new Product() - .setId(2L) - .setName("microwave") - .setSupplier("Delonghi") - .setPrice(1000D) - .setCost(1090D); + Product.builder() + .id(2L) + .name("microwave") + .supplier("Delonghi") + .price(1000D) + .cost(1090D).build(); Product refrigerator = - new Product() - .setId(3L) - .setName("refrigerator") - .setSupplier("Botsch") - .setPrice(1000D) - .setCost(1090D); + Product.builder() + .id(3L) + .name("refrigerator") + .supplier("Botsch") + .price(1000D) + .cost(1090D).build(); Product airConditioner = - new Product() - .setId(4L) - .setName("airConditioner") - .setSupplier("LG") - .setPrice(1000D) - .setCost(1090D); + Product.builder() + .id(4L) + .name("airConditioner") + .supplier("LG") + .price(1000D) + .cost(1090D).build(); List<Product> products = new ArrayList<>(Arrays.asList(tv, microwave, refrigerator, airConditioner)); ProductResource productResource = new ProductResource(products); diff --git a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/Product.java b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/Product.java index 2fed53dda8a9..633c0b82997d 100644 --- a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/Product.java +++ b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/Product.java @@ -24,9 +24,18 @@ */ package com.iluwatar.datatransfer.product; +import lombok.AllArgsConstructor; +import lombok.Builder; +import lombok.Data; +import lombok.NoArgsConstructor; + /** * {@link Product} is a entity class for product entity. This class act as entity in the demo. */ +@Data +@Builder +@NoArgsConstructor +@AllArgsConstructor public final class Product { private Long id; private String name; @@ -34,82 +43,14 @@ public final class Product { private Double cost; private String supplier; - /** - * Constructor. - * - * @param id product id - * @param name product name - * @param price product price - * @param cost product cost - * @param supplier product supplier - */ - public Product(Long id, String name, Double price, Double cost, String supplier) { - this.id = id; - this.name = name; - this.price = price; - this.cost = cost; - this.supplier = supplier; - } - - /** - * Constructor. - */ - public Product() { - } - - public Long getId() { - return id; - } - - public Product setId(Long id) { - this.id = id; - return this; - } - - public String getName() { - return name; - } - - public Product setName(String name) { - this.name = name; - return this; - } - - public Double getPrice() { - return price; - } - - public Product setPrice(Double price) { - this.price = price; - return this; - } - - public Double getCost() { - return cost; - } - - public Product setCost(Double cost) { - this.cost = cost; - return this; - } - - public String getSupplier() { - return supplier; - } - - public Product setSupplier(String supplier) { - this.supplier = supplier; - return this; - } - @Override public String toString() { return "Product{" - + "id=" + id - + ", name='" + name + '\'' - + ", price=" + price - + ", cost=" + cost - + ", supplier='" + supplier + '\'' - + '}'; + + "id=" + id + + ", name='" + name + '\'' + + ", price=" + price + + ", cost=" + cost + + ", supplier='" + supplier + '\'' + + '}'; } } diff --git a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/ProductResource.java b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/ProductResource.java index a48f0bc8d702..2c3158fe5441 100644 --- a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/ProductResource.java +++ b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/product/ProductResource.java @@ -50,11 +50,11 @@ public ProductResource(final List<Product> products) { */ public List<ProductDto.Response.Private> getAllProductsForAdmin() { return products - .stream() - .map(p -> new ProductDto.Response.Private().setId(p.getId()).setName(p.getName()) - .setCost(p.getCost()) - .setPrice(p.getPrice())) - .collect(Collectors.toList()); + .stream() + .map(p -> new ProductDto.Response.Private().setId(p.getId()).setName(p.getName()) + .setCost(p.getCost()) + .setPrice(p.getPrice())) + .collect(Collectors.toList()); } /** @@ -64,10 +64,10 @@ public List<ProductDto.Response.Private> getAllProductsForAdmin() { */ public List<ProductDto.Response.Public> getAllProductsForCustomer() { return products - .stream() - .map(p -> new ProductDto.Response.Public().setId(p.getId()).setName(p.getName()) - .setPrice(p.getPrice())) - .collect(Collectors.toList()); + .stream() + .map(p -> new ProductDto.Response.Public().setId(p.getId()).setName(p.getName()) + .setPrice(p.getPrice())) + .collect(Collectors.toList()); } /** @@ -76,12 +76,13 @@ public List<ProductDto.Response.Public> getAllProductsForCustomer() { * @param createProductDto save new product to list. */ public void save(ProductDto.Request.Create createProductDto) { - products.add(new Product() - .setId((long) (products.size() + 1)) - .setName(createProductDto.getName()) - .setSupplier(createProductDto.getSupplier()) - .setPrice(createProductDto.getPrice()) - .setCost(createProductDto.getCost())); + products.add(Product.builder() + .id((long) (products.size() + 1)) + .name(createProductDto.getName()) + .supplier(createProductDto.getSupplier()) + .price(createProductDto.getPrice()) + .cost(createProductDto.getCost()) + .build()); } /**

test

val

burno1

train

iluwatar/java-design-patterns/2107_2108

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2107

iluwatar/java-design-patterns/2108

505454cbae5fbb58bfd2df51beb48b3307c4f6e6

3454a9817509ab455a14cf73fb367e591ff717a2

Add lombok to step-builder pattern

This pattern doesn't have lombok added to it, we should add to have cleaner code.

diff --git a/step-builder/src/main/java/com/iluwatar/stepbuilder/Character.java b/step-builder/src/main/java/com/iluwatar/stepbuilder/Character.java index 6f04fc09d6eb..05ba3e733c48 100644 --- a/step-builder/src/main/java/com/iluwatar/stepbuilder/Character.java +++ b/step-builder/src/main/java/com/iluwatar/stepbuilder/Character.java @@ -26,9 +26,16 @@ import java.util.List; +import lombok.Getter; +import lombok.Setter; + + + /** * The class with many parameters. */ +@Getter +@Setter public class Character { private String name; @@ -42,53 +49,6 @@ public Character(String name) { this.name = name; } - public String getName() { - return name; - } - - public void setName(String name) { - this.name = name; - } - - public String getFighterClass() { - return fighterClass; - } - - public void setFighterClass(String fighterClass) { - this.fighterClass = fighterClass; - } - - public String getWizardClass() { - return wizardClass; - } - - public void setWizardClass(String wizardClass) { - this.wizardClass = wizardClass; - } - - public String getWeapon() { - return weapon; - } - - public void setWeapon(String weapon) { - this.weapon = weapon; - } - - public String getSpell() { - return spell; - } - - public void setSpell(String spell) { - this.spell = spell; - } - - public List<String> getAbilities() { - return abilities; - } - - public void setAbilities(List<String> abilities) { - this.abilities = abilities; - } @Override public String toString() {

test

val

burno1

train

iluwatar/java-design-patterns/2082_2109

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2082

iluwatar/java-design-patterns/2109

505454cbae5fbb58bfd2df51beb48b3307c4f6e6

608f6d21cf94cb7a8621b910d865df415b34ed1a

Translate template-method pattern readme to Korean

I'll translate the readme file of the template-method design pattern to Korean and place it under localization/ko/template-method.

diff --git a/localization/ko/template-method/README.md b/localization/ko/template-method/README.md new file mode 100644 index 000000000000..4aeae0c3c738 --- /dev/null +++ b/localization/ko/template-method/README.md @@ -0,0 +1,148 @@ +--- +layout: pattern +title: Template method +folder: template-method +permalink: /patterns/template-method/ko +categories: Behavioral +language: ko +tags: +- Gang of Four +--- + +## 의도 + +동작 상의 알고리즘의 뼈대를 정의하고 일부 단계들을 하위 클래스에게 미룹니다. 템플릿 메소드는 알고리즘 구조의 변경없이 하위 클래스들이 알고리즘의 특정 단계들을 재정의할 수 있게 합니다. + +## 설명 + +실제 예제 + +> 일반적으로 물건을 훔치는 절차는 동일합니다. 첫번째 단계로 대상을 고릅니다. 다음 단계로 대상을 어느정도 혼란스럽게 만듭니다. 마지막 단계로 물건을 훔칩니다. 하지만, 이 단계를 실행하는 구체적인 방법에는 여러가지가 있습니다. + +쉽게 말하자면 + +> 템플릿 메소드 패턴은 일반적인 단계의 아웃라인을 부모 클래스에 제시합니다. 그리고 구체적인 자식 클래스의 구현으로 디테일한 사항들을 정의합니다. + +Wikipedia에 의하면 + +> 객체지향 프로그래밍에서, 템플릿 메소드는 디자인 패턴 책에서 감마를 포함한 책의 저자들이 확인한 행동 디자인 패턴 중 하나입니다. 템플릿 메소드는 보통 추상 수퍼클래스인 수퍼클래스에서의 메소드이며 수많은 high-level 단계들의 관점에서 동작의 뼈대를 정의합니다. 이러한 절차들은 템플릿 메소드와 동일한 클래스의 추가적인 헬퍼 메소드들에 의해 구현됩니다. + +**코드 예제** + +먼저 구체적인 구현과 함께 템플릿 방법 클래스를 소개합니다. 하위클래스들이 템플릿 메소드를 재정의하지 않는 것을 확실히 하기위해 템플릿 메소드(예제에서는 메소드명`steal`)는 `final`로 선언해야 합니다. 그렇지 않으면 기본 클래스에 정의된 뼈대는 하위 클래스에서 재정의될 수 있습니다. + + +```java +@Slf4j +public abstract class StealingMethod { + + protected abstract String pickTarget(); + + protected abstract void confuseTarget(String target); + + protected abstract void stealTheItem(String target); + + public final void steal() { + var target = pickTarget(); + LOGGER.info("The target has been chosen as {}.", target); + confuseTarget(target); + stealTheItem(target); + } +} + +@Slf4j +public class SubtleMethod extends StealingMethod { + + @Override + protected String pickTarget() { + return "shop keeper"; + } + + @Override + protected void confuseTarget(String target) { + LOGGER.info("Approach the {} with tears running and hug him!", target); + } + + @Override + protected void stealTheItem(String target) { + LOGGER.info("While in close contact grab the {}'s wallet.", target); + } +} + +@Slf4j +public class HitAndRunMethod extends StealingMethod { + + @Override + protected String pickTarget() { + return "old goblin woman"; + } + + @Override + protected void confuseTarget(String target) { + LOGGER.info("Approach the {} from behind.", target); + } + + @Override + protected void stealTheItem(String target) { + LOGGER.info("Grab the handbag and run away fast!"); + } +} +``` + +템플릿 메소드를 담고 있는 반쪽짜리 도적 클래스입니다. + +```java +public class HalflingThief { + + private StealingMethod method; + + public HalflingThief(StealingMethod method) { + this.method = method; + } + + public void steal() { + method.steal(); + } + + public void changeMethod(StealingMethod method) { + this.method = method; + } +} +``` + +그리고 마지막으로, 반쪽짜리 도둑이 다른 도둑질 방법을 어떻게 활용하는지 보여줍니다. + +```java + var thief = new HalflingThief(new HitAndRunMethod()); + thief.steal(); + thief.changeMethod(new SubtleMethod()); + thief.steal(); +``` + +## 클래스 다이어그램 + + + +## 적용 가능성 + +템플릿 메소드는 사용되어야합니다. + +* 알고리즘의 변하지않는 부분을 한번만 구현하고, 다양할 수 있는 행위의 구현을 서브클래스에게 맡기기 위해 +* 중복되는 코드를 피하기위해 서브클래스들 사이의 공통적인 행위를 공통 클래스에서 고려하고 현지화해야 하는 경우. 이것은 Opdyke 와 Johonson이 묘사한 "일반화하기 위한 수정"의 좋은 예입니다. 먼저 기존 코드들 간의 차이를 확인한 다음 새로운 동작으로 구분합니다. 마지막으로, 다른 코드들을 새로운 동작중 하나를 호출하는 템플릿 메소드로 대체합니다. +* 서브클래스들의 확장을 컨트롤하기 위해. 특정 지점에서 "훅" 작업을 호출하여 해당 지점에서만 확장을 허용하는 템플릿 메서드를 정의할 수 있습니다. + +## 튜토리얼 + +* [Template-method Pattern Tutorial](https://www.journaldev.com/1763/template-method-design-pattern-in-java) + +## 실제 사례 + +* [javax.servlet.GenericServlet.init](https://jakarta.ee/specifications/servlet/4.0/apidocs/javax/servlet/GenericServlet.html#init--): + Method `GenericServlet.init(ServletConfig config)` calls the parameterless method `GenericServlet.init()` which is intended to be overridden in subclasses. + Method `GenericServlet.init(ServletConfig config)` is the template method in this example. + +## 크레딧 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) +* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7)

train

val

seongkyu-lim

train

iluwatar/java-design-patterns/2124_2126

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2124

iluwatar/java-design-patterns/2126

3dcda6f2457b27e4b0652ddd9f07e9c6b5b6d4c1

df52e1fd4e57abde9356b581e4b0f87d5eba5ccd

Translate the adapter readme to Spanish

I'll translate the readme file of the adapter design pattern to Spanish and place it under localization.es.adapter.

diff --git a/adapter/README.md b/adapter/README.md index 2539d0b45fee..7fa4af751b32 100644 --- a/adapter/README.md +++ b/adapter/README.md @@ -112,12 +112,12 @@ Use the Adapter pattern when Class and object adapters have different trade-offs. A class adapter * Adapts Adaptee to Target by committing to a concrete Adaptee class. As a consequence, a class adapter won’t work when we want to adapt a class and all its subclasses. -* Let’s Adapter override some of Adaptee’s behavior since Adapter is a subclass of Adaptee. +* Lets Adapter override some of Adaptee’s behavior since Adapter is a subclass of Adaptee. * Introduces only one object, and no additional pointer indirection is needed to get to the adaptee. An object adapter -* Lets a single Adapter work with many Adaptees—that is, the Adaptee itself and all of its subclasses (if any). The Adapter can also add functionality to all Adaptees at once. +* Lets a single Adapter work with many Adaptees, that is, the Adaptee itself and all of its subclasses (if any). The Adapter can also add functionality to all Adaptees at once. * Makes it harder to override Adaptee behavior. It will require subclassing Adaptee and making the Adapter refer to the subclass rather than the Adaptee itself. diff --git a/localization/es/adapter/README.md b/localization/es/adapter/README.md new file mode 100644 index 000000000000..31ffeb4bf442 --- /dev/null +++ b/localization/es/adapter/README.md @@ -0,0 +1,136 @@ +--- +title: Adapter +category: Structural +language: es +tags: + - Gang of Four +--- + +## También conocido como +Wrapper + +## Propósito +Convertir la interfaz de una clase en otra que espera el cliente. El patrón Adapter permite a clases funcionar en conjunto con otras clases con las que no podrían de otra forma por problemas de compatibilidad. + +## Explicación + +Ejemplo del mundo real + +> Imagina que tienes unas imágenes en una tarjeta de memoria y quieres transferirlas a tu ordenador. Para transferirlas necesitas algún tipo de adaptador compatible con los puertos de tu ordenador que te permita introducir tu tarjeta. En este caso el lector de tarjetas es un adaptador (adapter). +> Otro ejemplo podría ser el famoso adaptador de corriente; un enchufe con tres patas no se puede conectar a una toma de corriente con dos agujeros, necesita un adaptador para hacerlo compatible con la toma de corriente. +> Otro ejemplo mas seria un traductor traduciendo palabras de una persona para otra. + +En otras palabras + +> El patrón Adapter permite envolver un objeto en un adaptador para hacerlo compatible con una clase con la que seria incompatible de otra manera. + +Según Wikipedia + +> En ingeniería de software el patrón Adapter es un patrón de diseño de software que permite usar la interfaz de una clase existente como otra interfaz diferente. A menudo es utilizado para hacer que clases existentes trabajen con otras clases sin necesidad de modificar su código fuente. + +**Ejemplo Programático** + +Toma como ejemplo un capitán que solo puede usar botes de remo y no puede navegar en absoluto. + +Primero tenemos las interfaces `RowingBoat` (bote de remo) y `FishingBoat` (bote de pesca). + +```java +public interface RowingBoat { + void row(); +} + +@Slf4j +public class FishingBoat { + public void sail() { + LOGGER.info("The fishing boat is sailing"); + } +} +``` + +Y el capitán espera una implementación de la interfaz `RowingBoat` (bote de remo) para poder moverse. + +```java +public class Captain { + + private final RowingBoat rowingBoat; + // default constructor and setter for rowingBoat + public Captain(RowingBoat rowingBoat) { + this.rowingBoat = rowingBoat; + } + + public void row() { + rowingBoat.row(); + } +} +``` + +Ahora supongamos que viene un grupo de piratas y nuestro capitán tiene que escapar pero solo hay un bote de pesca. Necesitamos crear un adaptador que permita al capitán usar el bote de pesca con sus habilidades para usar botes de remo. + +```java +@Slf4j +public class FishingBoatAdapter implements RowingBoat { + + private final FishingBoat boat; + + public FishingBoatAdapter() { + boat = new FishingBoat(); + } + + @Override + public void row() { + boat.sail(); + } +} +``` + +Y ahora el `Captain` (capitán) puede usar el `FishingBoat` (bote de pesca) para escapar de los piratas. + +```java +var captain = new Captain(new FishingBoatAdapter()); +captain.row(); +``` + +## Diagrama de clases + + +## Aplicación +Usa el patrón Adapter cuando + +* Quieres usar una clase existente y su interfaz no coincide con la que necesitas. +* Quieres crear una clase reutilizable que coopere con clases que no están relacionadas o con las que su cooperación no estaba planeada, esto es, clases que no necesariamente tienen interfaces compatibles. +* Necesitas usar varias subclases existentes pero es impráctico adaptar su interfaz creando subclases para todas. Un adaptador puede adaptar la interfaz de la clase padre. +* Muchas aplicaciones que usan librerías de terceros usan adaptadores como capas intermedias entre la aplicación y la librería para desacoplar la aplicación de la librería. Si es necesario usar otra librería solo hace falta crear un adaptador para la nueva librería sin necesidad de modificar el código de la aplicación. + +## Tutoriales + +* [Dzone](https://dzone.com/articles/adapter-design-pattern-in-java) +* [Refactoring Guru](https://refactoring.guru/design-patterns/adapter/java/example) +* [Baeldung](https://www.baeldung.com/java-adapter-pattern) + +## Consecuencias +Los adaptadores de clases y objetos tienen distintas cualidades. Un adaptador de clases + +* Hace la adaptación quedando enlazado a una clase adaptada concreta. Como consecuencia un adaptador de clases no funcionará cuando queramos adaptar una clase y sus subclases. +* Permite al adaptador modificar el comportamiento de la clase adaptada porque el adaptador es una subclase de la clase adaptada. +* Usa un solo objeto y no es necesario usar punteros adicionales para referenciar la clase adaptada. + +Un adaptador de objetos + +* Permite a un solo adaptador trabajar con varias clases, esto es, con la clase adaptada y todas sus subclases (si tiene alguna). El adaptador también puede añadir funcionalidad a todas las clases adaptadas a la vez. +* Hace mas complicado modificar el comportamiento de la clase adaptada. Sería necesario hacer una subclase de la clase a adaptar y hacer que el adaptador referencie la subclase en lugar de la clase a adaptar. + + +## Ejemplos del mundo real + +* [java.util.Arrays#asList()](http://docs.oracle.com/javase/8/docs/api/java/util/Arrays.html#asList%28T...%29) +* [java.util.Collections#list()](https://docs.oracle.com/javase/8/docs/api/java/util/Collections.html#list-java.util.Enumeration-) +* [java.util.Collections#enumeration()](https://docs.oracle.com/javase/8/docs/api/java/util/Collections.html#enumeration-java.util.Collection-) +* [javax.xml.bind.annotation.adapters.XMLAdapter](http://docs.oracle.com/javase/8/docs/api/javax/xml/bind/annotation/adapters/XmlAdapter.html#marshal-BoundType-) + + +## Créditos + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=48d37c67fb3d845b802fa9b619ad8f31) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) +* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7)

val

val

aitorfi

train

iluwatar/java-design-patterns/1261_2134

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1261

iluwatar/java-design-patterns/2134

03feaa9faf7bb8de209b8fa72a8d3559629e6c64

fcaf72fdf8ccfe4da7d4207f6c042d1a43b3d535

Collecting Parameter pattern

https://wiki.c2.com/?CollectingParameter

diff --git a/collecting-parameter/README.md b/collecting-parameter/README.md new file mode 100644 index 000000000000..a57b8d2991da --- /dev/null +++ b/collecting-parameter/README.md @@ -0,0 +1,197 @@ +--- +title: Collecting Parameter +category: Idiom +language: en +tags: +- Generic +--- + +## Name +Collecting Parameter + +## Intent +To store the collaborative result of numerous methods within a collection. + +## Explanation +### Real-world example +Within a large corporate building, there exists a global printer queue that is a collection of all the printing jobs +that are currently pending. Various floors contain different models of printers, each having a different printing +policy. We must construct a program that can continually add appropriate printing jobs to a collection, which is called the *collecting parameter*. + +### In plain words +Instead of having one giant method that contains numerous policies for collecting information into a variable, we can +create numerous smaller functions that each take parameter, and append new information. We can pass the parameter to +all of these smaller functions and by the end, we will have what we wanted originally. This time, the code is cleaner +and easier to understand. Because the larger function has been broken down, the code is also easier to modify as changes +are localised to the smaller functions. + +### Wikipedia says +In the Collecting Parameter idiom a collection (list, map, etc.) is passed repeatedly as a parameter to a method which adds items to the collection. + +### Programmatic example +Coding our example from above, we may use the collection `result` as a collecting parameter. The following restrictions +are implemented: +- If an A4 paper is coloured, it must also be single-sided. All other non-coloured papers are accepted +- A3 papers must be non-coloured and single-sided +- A2 papers must be single-page, single-sided, and non-coloured + +```java +package com.iluwatar.collectingparameter; +import java.util.LinkedList; +import java.util.Queue; +public class App { + static PrinterQueue printerQueue = PrinterQueue.getInstance(); + + /** + * Program entry point. + * + * @param args command line args + */ + public static void main(String[] args) { + /* + Initialising the printer queue with jobs + */ + printerQueue.addPrinterItem(new PrinterItem(PaperSizes.A4, 5, false, false)); + printerQueue.addPrinterItem(new PrinterItem(PaperSizes.A3, 2, false, false)); + printerQueue.addPrinterItem(new PrinterItem(PaperSizes.A2, 5, false, false)); + + /* + This variable is the collecting parameter. + */ + var result = new LinkedList<PrinterItem>(); + + /* + * Using numerous sub-methods to collaboratively add information to the result collecting parameter + */ + addA4Papers(result); + addA3Papers(result); + addA2Papers(result); + } +} +``` + +We use the `addA4Paper`, `addA3Paper`, and `addA2Paper` methods to populate the `result` collecting parameter with the +appropriate print jobs as per the policy described previously. The three policies are encoded below, + +```java +public class App { + static PrinterQueue printerQueue = PrinterQueue.getInstance(); + /** + * Adds A4 document jobs to the collecting parameter according to some policy that can be whatever the client + * (the print center) wants. + * + * @param printerItemsCollection the collecting parameter + */ + public static void addA4Papers(Queue<PrinterItem> printerItemsCollection) { + /* + Iterate through the printer queue, and add A4 papers according to the correct policy to the collecting parameter, + which is 'printerItemsCollection' in this case. + */ + for (PrinterItem nextItem : printerQueue.getPrinterQueue()) { + if (nextItem.paperSize.equals(PaperSizes.A4)) { + var isColouredAndSingleSided = nextItem.isColour && !nextItem.isDoubleSided; + if (isColouredAndSingleSided) { + printerItemsCollection.add(nextItem); + } else if (!nextItem.isColour) { + printerItemsCollection.add(nextItem); + } + } + } + } + + /** + * Adds A3 document jobs to the collecting parameter according to some policy that can be whatever the client + * (the print center) wants. The code is similar to the 'addA4Papers' method. The code can be changed to accommodate + * the wants of the client. + * + * @param printerItemsCollection the collecting parameter + */ + public static void addA3Papers(Queue<PrinterItem> printerItemsCollection) { + for (PrinterItem nextItem : printerQueue.getPrinterQueue()) { + if (nextItem.paperSize.equals(PaperSizes.A3)) { + + // Encoding the policy into a Boolean: the A3 paper cannot be coloured and double-sided at the same time + var isNotColouredAndSingleSided = !nextItem.isColour && !nextItem.isDoubleSided; + if (isNotColouredAndSingleSided) { + printerItemsCollection.add(nextItem); + } + } + } + } + + /** + * Adds A2 document jobs to the collecting parameter according to some policy that can be whatever the client + * (the print center) wants. The code is similar to the 'addA4Papers' method. The code can be changed to accommodate + * the wants of the client. + * + * @param printerItemsCollection the collecting parameter + */ + public static void addA2Papers(Queue<PrinterItem> printerItemsCollection) { + for (PrinterItem nextItem : printerQueue.getPrinterQueue()) { + if (nextItem.paperSize.equals(PaperSizes.A2)) { + + // Encoding the policy into a Boolean: the A2 paper must be single page, single-sided, and non-coloured. + var isNotColouredSingleSidedAndOnePage = nextItem.pageCount == 1 && !nextItem.isDoubleSided + && !nextItem.isColour; + if (isNotColouredSingleSidedAndOnePage) { + printerItemsCollection.add(nextItem); + } + } + } + } +} +``` + +Each method takes a collecting parameter as an argument. It then adds elements, taken from a global variable, +to this collecting parameter if each element satisfies a given criteria. These methods can have whatever policy the client desires. + +In this programmatic example, three print jobs are added to the queue. Only the first two print jobs should be added to +the collecting parameter as per the policy. The elements of the `result` variable after execution are, + +| paperSize | pageCount | isDoubleSided | isColour | +|-----------|-----------|---------------|----------| +| A4 | 5 | false | false | +| A3 | 2 | false | false | + +which is what we expected. + +## Class diagram + + +## Applicability +Use the Collecting Parameter design pattern when +- you want to return a collection or object that is the collaborative result of several methods +- You want to simplify a method that accumulates data as the original method is too complex + +## Tutorials +Tutorials for this method are found in: +- [Refactoring To Patterns](http://www.tarrani.net/RefactoringToPatterns.pdf) by Joshua Kerivsky +- [Smalltalk Best Practice Patterns](https://ptgmedia.pearsoncmg.com/images/9780134769042/samplepages/013476904X.pdf) by Kent Beck + +## Known uses +Joshua Kerivsky gives a real-world example in his book 'Refactoring to Patterns'. He gives an example of using the +Collecting Parameter Design Pattern to create a `toString()` method for an XML tree. Without using this design pattern, +this would require a bulky function with conditionals and concatenation that would worsen code readability. Such a method +can be broken down into smaller methods, each appending their own set of information to the collecting parameter. + +See this in [Refactoring To Patterns](http://www.tarrani.net/RefactoringToPatterns.pdf). + +## Consequences +Pros: +- Makes code more readable +- Avoids 'linkages', where numerous methods reference the same global variable +- Increases maintainability by decomposing larger functions + +Cons: +- May increase code length +- Adds 'layers' of methods + +## Related patterns +- [Compose Methods](https://www.geeksforgeeks.org/composite-design-pattern/) + +## Credits +Following books were used: +- [Refactoring To Patterns](http://www.tarrani.net/RefactoringToPatterns.pdf) by Joshua Kerivsky +- [Smalltalk Best Practice Patterns](https://ptgmedia.pearsoncmg.com/images/9780134769042/samplepages/013476904X.pdf) by Kent Beck +Sites: +- [Wiki](https://wiki.c2.com/?CollectingParameter) diff --git a/collecting-parameter/etc/collecting-parameter.urm.puml b/collecting-parameter/etc/collecting-parameter.urm.puml new file mode 100644 index 000000000000..06320fa022ee --- /dev/null +++ b/collecting-parameter/etc/collecting-parameter.urm.puml @@ -0,0 +1,39 @@ +@startuml +package com.iluwatar.collectingparameter { + class App { + ~ printerQueue : PrinterQueue {static} + + App() + + addValidA2Papers(printerItemsCollection : Queue<PrinterItem>) {static} + + addValidA3Papers(printerItemsCollection : Queue<PrinterItem>) {static} + + addValidA4Papers(printerItemsCollection : Queue<PrinterItem>) {static} + + main(args : String[]) {static} + } + ~enum PaperSizes { + + A2 {static} + + A3 {static} + + A4 {static} + + valueOf(name : String) : PaperSizes {static} + + values() : PaperSizes[] {static} + } + class PrinterItem { + ~ isColour : boolean + ~ isDoubleSided : boolean + ~ pageCount : int + ~ paperSize : PaperSizes + + PrinterItem(paperSize : PaperSizes, pageCount : int, isDoubleSided : boolean, isColour : boolean) + } + class PrinterQueue { + ~ currentInstance : PrinterQueue {static} + - printerItemQueue : Queue<PrinterItem> + - PrinterQueue() + + addPrinterItem(printerItem : PrinterItem) + + emptyQueue() + + getInstance() : PrinterQueue {static} + + getPrinterQueue() : Queue<PrinterItem> + } +} +PrinterQueue --> "-currentInstance" PrinterQueue +PrinterQueue --> "-printerItemQueue" PrinterItem +App --> "-printerQueue" PrinterQueue +PrinterItem --> "-paperSize" PaperSizes +@enduml \ No newline at end of file diff --git a/collecting-parameter/pom.xml b/collecting-parameter/pom.xml new file mode 100644 index 000000000000..8f7fdc2b52db --- /dev/null +++ b/collecting-parameter/pom.xml @@ -0,0 +1,67 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + + The MIT License + Copyright © 2014-2022 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <parent> + <artifactId>java-design-patterns</artifactId> + <groupId>com.iluwatar</groupId> + <version>1.26.0-SNAPSHOT</version> + </parent> + <modelVersion>4.0.0</modelVersion> + <artifactId>collecting-parameter</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>junit</groupId> + <artifactId>junit</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.collectingparameter.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> diff --git a/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/App.java b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/App.java new file mode 100644 index 000000000000..93ead620da95 --- /dev/null +++ b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/App.java @@ -0,0 +1,138 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.collectingparameter; + +import java.util.LinkedList; +import java.util.Queue; + +/** + * The Collecting Parameter Design Pattern aims to return a result that is the collaborative result of several + * methods. This design pattern uses a 'collecting parameter' that is passed to several functions, accumulating results + * as it travels from method-to-method. This is different to the Composed Method design pattern, where a single + * collection is modified via several methods. + * + * <p>This example is inspired by Kent Beck's example in his book, 'Smalltalk Best Practice Patterns'. The context for this + * situation is that there is a single printer queue {@link PrinterQueue} that holds numerous print jobs + * {@link PrinterItem} that must be distributed to various print centers. + * Each print center has its own requirements and printing limitations. In this example, the following requirements are: + * If an A4 document is coloured, it must also be single-sided. All other non-coloured A4 documents are accepted. + * All A3 documents must be non-coloured and single sided. All A2 documents must be a single page, single sided, and + * non-coloured. + * + * <p>A collecting parameter (the result variable) is used to filter the global printer queue so that it meets the + * requirements for this centre, + **/ + +public class App { + static PrinterQueue printerQueue = PrinterQueue.getInstance(); + + /** + * Program entry point. + * + * @param args command line args + */ + public static void main(String[] args) { + /* + Initialising the printer queue with jobs + */ + printerQueue.addPrinterItem(new PrinterItem(PaperSizes.A4, 5, false, false)); + printerQueue.addPrinterItem(new PrinterItem(PaperSizes.A3, 2, false, false)); + printerQueue.addPrinterItem(new PrinterItem(PaperSizes.A2, 5, false, false)); + + /* + This variable is the collecting parameter, and will store the policy abiding print jobs. + */ + var result = new LinkedList<PrinterItem>(); + + /* + Adding A4, A3, and A2 papers that obey the policy + */ + addValidA4Papers(result); + addValidA3Papers(result); + addValidA2Papers(result); + } + + /** + * Adds A4 document jobs to the collecting parameter according to some policy that can be whatever the client + * (the print center) wants. + * + * @param printerItemsCollection the collecting parameter + */ + public static void addValidA4Papers(Queue<PrinterItem> printerItemsCollection) { + /* + Iterate through the printer queue, and add A4 papers according to the correct policy to the collecting parameter, + which is 'printerItemsCollection' in this case. + */ + for (PrinterItem nextItem : printerQueue.getPrinterQueue()) { + if (nextItem.paperSize.equals(PaperSizes.A4)) { + var isColouredAndSingleSided = nextItem.isColour && !nextItem.isDoubleSided; + if (isColouredAndSingleSided || !nextItem.isColour) { + printerItemsCollection.add(nextItem); + } + } + } + } + + /** + * Adds A3 document jobs to the collecting parameter according to some policy that can be whatever the client + * (the print center) wants. The code is similar to the 'addA4Papers' method. The code can be changed to accommodate + * the wants of the client. + * + * @param printerItemsCollection the collecting parameter + */ + public static void addValidA3Papers(Queue<PrinterItem> printerItemsCollection) { + for (PrinterItem nextItem : printerQueue.getPrinterQueue()) { + if (nextItem.paperSize.equals(PaperSizes.A3)) { + + // Encoding the policy into a Boolean: the A3 paper cannot be coloured and double-sided at the same time + var isNotColouredAndSingleSided = !nextItem.isColour && !nextItem.isDoubleSided; + if (isNotColouredAndSingleSided) { + printerItemsCollection.add(nextItem); + } + } + } + } + + /** + * Adds A2 document jobs to the collecting parameter according to some policy that can be whatever the client + * (the print center) wants. The code is similar to the 'addA4Papers' method. The code can be changed to accommodate + * the wants of the client. + * + * @param printerItemsCollection the collecting parameter + */ + public static void addValidA2Papers(Queue<PrinterItem> printerItemsCollection) { + for (PrinterItem nextItem : printerQueue.getPrinterQueue()) { + if (nextItem.paperSize.equals(PaperSizes.A2)) { + + // Encoding the policy into a Boolean: the A2 paper must be single page, single-sided, and non-coloured. + var isNotColouredSingleSidedAndOnePage = nextItem.pageCount == 1 && !nextItem.isDoubleSided + && !nextItem.isColour; + if (isNotColouredSingleSidedAndOnePage) { + printerItemsCollection.add(nextItem); + } + } + } + } +} diff --git a/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PaperSizes.java b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PaperSizes.java new file mode 100644 index 000000000000..352bf3cc241a --- /dev/null +++ b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PaperSizes.java @@ -0,0 +1,7 @@ +package com.iluwatar.collectingparameter; + +enum PaperSizes { + A2, + A3, + A4 +} diff --git a/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PrinterItem.java b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PrinterItem.java new file mode 100644 index 000000000000..629cdb62500e --- /dev/null +++ b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PrinterItem.java @@ -0,0 +1,34 @@ +package com.iluwatar.collectingparameter; + +import java.util.Objects; + +/** + * This class represents a Print Item, that should be added to the queue. + **/ +public class PrinterItem { + PaperSizes paperSize; + int pageCount; + boolean isDoubleSided; + boolean isColour; + + /** + * The {@link PrinterItem} constructor. + **/ + public PrinterItem(PaperSizes paperSize, int pageCount, boolean isDoubleSided, boolean isColour) { + if (!Objects.isNull(paperSize)) { + this.paperSize = paperSize; + } else { + throw new IllegalArgumentException(); + } + + if (pageCount > 0) { + this.pageCount = pageCount; + } else { + throw new IllegalArgumentException(); + } + + this.isColour = isColour; + this.isDoubleSided = isDoubleSided; + + } +} diff --git a/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PrinterQueue.java b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PrinterQueue.java new file mode 100644 index 000000000000..2408d076c7c6 --- /dev/null +++ b/collecting-parameter/src/main/java/com/iluwatar/collectingparameter/PrinterQueue.java @@ -0,0 +1,52 @@ +package com.iluwatar.collectingparameter; + +import java.util.LinkedList; +import java.util.Objects; +import java.util.Queue; + +/** + * This class represents a singleton Printer Queue. It contains a queue that can be filled up with {@link PrinterItem}. + **/ +public class PrinterQueue { + + static PrinterQueue currentInstance = null; + private final Queue<PrinterItem> printerItemQueue; + + /** + * This class is a singleton. The getInstance method will ensure that only one instance exists at a time. + */ + public static PrinterQueue getInstance() { + if (Objects.isNull(currentInstance)) { + currentInstance = new PrinterQueue(); + } + return currentInstance; + } + + /** + * Empty the printer queue. + */ + public void emptyQueue() { + currentInstance.getPrinterQueue().clear(); + } + + /** + * Private constructor prevents instantiation, unless using the getInstance() method. + */ + private PrinterQueue() { + printerItemQueue = new LinkedList<>(); + } + + public Queue<PrinterItem> getPrinterQueue() { + return currentInstance.printerItemQueue; + } + + /** + * Adds a single print job to the queue. + * + * @param printerItem The printing job to be added to the queue + */ + public void addPrinterItem(PrinterItem printerItem) { + currentInstance.getPrinterQueue().add(printerItem); + } + +} diff --git a/pom.xml b/pom.xml index 3aacbad55d4a..c14cf5dbdcb3 100644 --- a/pom.xml +++ b/pom.xml @@ -84,6 +84,7 @@ </properties> <modules> <module>abstract-factory</module> + <module>collecting-parameter</module> <module>monitor</module> <module>tls</module> <module>builder</module>

diff --git a/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/AppTest.java b/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/AppTest.java new file mode 100644 index 000000000000..57f9037778ae --- /dev/null +++ b/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/AppTest.java @@ -0,0 +1,39 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.collectingparameter; + +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +class AppTest { + /** + * Checks whether {@link App} executes without throwing exception + */ + @Test + void executesWithoutException() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} diff --git a/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/CollectingParameterTest.java b/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/CollectingParameterTest.java new file mode 100644 index 000000000000..53b7a4635df1 --- /dev/null +++ b/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/CollectingParameterTest.java @@ -0,0 +1,55 @@ +package com.iluwatar.collectingparameter; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.Timeout; + +import java.util.LinkedList; +import java.util.Queue; + +class CollectingParameterTest { + + @Test + @Timeout(1000) + void testCollectingParameter() { + PrinterQueue printerQueue = PrinterQueue.getInstance(); + printerQueue.emptyQueue(); + + PrinterItem item1 = new PrinterItem(PaperSizes.A4, 1, false, true); + PrinterItem item2 = new PrinterItem(PaperSizes.A4, 10, true, false); + PrinterItem item3 = new PrinterItem(PaperSizes.A4, 4, true, true); + PrinterItem item4 = new PrinterItem(PaperSizes.A3, 9, false, false); + PrinterItem item5 = new PrinterItem(PaperSizes.A3, 3, true, true); + PrinterItem item6 = new PrinterItem(PaperSizes.A3, 3, false, true); + PrinterItem item7 = new PrinterItem(PaperSizes.A3, 3, true, false); + PrinterItem item8 = new PrinterItem(PaperSizes.A2, 1, false, false); + PrinterItem item9 = new PrinterItem(PaperSizes.A2, 2, false, false); + PrinterItem item10 = new PrinterItem(PaperSizes.A2, 1, true, false); + PrinterItem item11 = new PrinterItem(PaperSizes.A2, 1, false, true); + + printerQueue.addPrinterItem(item1); + printerQueue.addPrinterItem(item2); + printerQueue.addPrinterItem(item3); + printerQueue.addPrinterItem(item4); + printerQueue.addPrinterItem(item5); + printerQueue.addPrinterItem(item6); + printerQueue.addPrinterItem(item7); + printerQueue.addPrinterItem(item8); + printerQueue.addPrinterItem(item9); + printerQueue.addPrinterItem(item10); + printerQueue.addPrinterItem(item11); + + Queue<PrinterItem> result = new LinkedList<>(); + App.addValidA4Papers(result); + App.addValidA3Papers(result); + App.addValidA2Papers(result); + + Queue<PrinterItem> testResult = new LinkedList<>(); + testResult.add(item1); + testResult.add(item2); + testResult.add(item4); + testResult.add(item8); + + Assertions.assertArrayEquals(testResult.toArray(), result.toArray()); + } +} diff --git a/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/PrinterQueueTest.java b/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/PrinterQueueTest.java new file mode 100644 index 000000000000..8371732f66e0 --- /dev/null +++ b/collecting-parameter/src/test/java/com/iluwatar/collectingparameter/PrinterQueueTest.java @@ -0,0 +1,34 @@ +package com.iluwatar.collectingparameter; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.Timeout; + +import java.util.LinkedList; +import java.util.Queue; + +import static org.junit.jupiter.api.Assertions.*; + +class PrinterQueueTest { + + @Test + @Timeout(1000) + void singletonTest() { + PrinterQueue printerQueue1 = PrinterQueue.getInstance(); + PrinterQueue printerQueue2 = PrinterQueue.getInstance(); + assertSame(printerQueue1, printerQueue2); + } + + @Test() + @Timeout(1000) + void negativePageCount() throws IllegalArgumentException { + Assertions.assertThrows(IllegalArgumentException.class, () -> new PrinterItem(PaperSizes.A4, -1, true, true)); + } + + @Test() + @Timeout(1000) + void nullPageSize() throws IllegalArgumentException { + Assertions.assertThrows(IllegalArgumentException.class, () -> new PrinterItem(null, 1, true, true)); + } + +} \ No newline at end of file

train

val

iluwatar

train

iluwatar/java-design-patterns/1275_2150

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1275

iluwatar/java-design-patterns/2150

953f9a4e0c0acf12342937bb96fe724393189875

b103e44ecd61c24f9eb0550fe01d6ca2419b6abd

Serialized Entity pattern

https://www.oreilly.com/library/view/j2ee-design-patterns/0596004273/re21.html

diff --git a/pom.xml b/pom.xml index 7ed97bcae754..c0ead428cba0 100644 --- a/pom.xml +++ b/pom.xml @@ -215,6 +215,7 @@ <module>composite-view</module> <module>metadata-mapping</module> <module>service-to-worker</module> + <module>serialized-entity</module> <module>identity-map</module> </modules> <repositories> diff --git a/serialized-entity/README.md b/serialized-entity/README.md new file mode 100644 index 000000000000..a0a3853f9c63 --- /dev/null +++ b/serialized-entity/README.md @@ -0,0 +1,221 @@ +--- +title: Serialized Entity Pattern +categories: Architectural +language: en +tags: + - Data access +--- + + +## Intent + +To easily persist Java objects to the database. + +## Explanation +Java serialization allow us to convert the object to a set of bytes. We can store these bytes into database as +BLOB(binary long objects) and read them at any time and reconstruct them into Java objects. + + +**Programmatic Example** + +Walking through our customers example, here's the basic `Customer` entity. + +```java +@Getter +@Setter +@EqualsAndHashCode +@ToString +@AllArgsConstructor +public class Country implements Serializable { + + private int code; + private String name; + private String continents; + private String language; + public static final long serialVersionUID = 7149851; + // Constructor -> + // getters and setters -> +} + +``` +Here is `CountrySchemaSql`, this class have method allow us to serialize `Country` object and insert it into the +database, also have a method that read serialized data from the database and deserialize it to `Country` object. + +```java +@Slf4j +public class CountrySchemaSql { + public static final String CREATE_SCHEMA_SQL = "CREATE TABLE IF NOT EXISTS WORLD (ID INT PRIMARY KEY, COUNTRY BLOB)"; + + public static final String DELETE_SCHEMA_SQL = "DROP TABLE WORLD IF EXISTS"; + + private Country country; + private DataSource dataSource; + + /** + * Public constructor. + * + * @param dataSource datasource + * @param country country + */ + public CountrySchemaSql(Country country, DataSource dataSource) { + this.country = new Country( + country.getCode(), + country.getName(), + country.getContinents(), + country.getLanguage() + ); + this.dataSource = dataSource; + } + + /** + * This method will serialize a Country object and store it to database. + * @return int type, if successfully insert a serialized object to database then return country code, else return -1. + * @throws IOException if any. + */ + public int insertCountry() throws IOException { + var sql = "INSERT INTO WORLD (ID, COUNTRY) VALUES (?, ?)"; + try (var connection = dataSource.getConnection(); + var preparedStatement = connection.prepareStatement(sql); + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + ObjectOutputStream oss = new ObjectOutputStream(baos)) { + + oss.writeObject(country); + oss.flush(); + + preparedStatement.setInt(1, country.getCode()); + preparedStatement.setBlob(2, new ByteArrayInputStream(baos.toByteArray())); + preparedStatement.execute(); + return country.getCode(); + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + return -1; + } + + /** + * This method will select a data item from database and deserialize it. + * @return int type, if successfully select and deserialized object from database then return country code, + * else return -1. + * @throws IOException if any. + * @throws ClassNotFoundException if any. + */ + public int selectCountry() throws IOException, ClassNotFoundException { + var sql = "SELECT ID, COUNTRY FROM WORLD WHERE ID = ?"; + try (var connection = dataSource.getConnection(); + var preparedStatement = connection.prepareStatement(sql)) { + + preparedStatement.setInt(1, country.getCode()); + + try (ResultSet rs = preparedStatement.executeQuery()) { + if (rs.next()) { + Blob countryBlob = rs.getBlob("country"); + ByteArrayInputStream baos = new ByteArrayInputStream(countryBlob.getBytes(1, (int) countryBlob.length())); + ObjectInputStream ois = new ObjectInputStream(baos); + country = (Country) ois.readObject(); + LOGGER.info("Country: " + country); + } + return rs.getInt("id"); + } + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + return -1; + } + +} +``` + +This `App.java` will first delete a World table from the h2 database(if there is one) and create a new table called +`WORLD` to ensure we have a table we want. +It will then create two `Country` objects called `China` and `UnitedArabEmirates`, then create two `CountrySchemaSql` +objects and use objects `China` and `UnitedArabEmirates` as arguments. +Finally, call `SerializedChina.insertCountry()` and `serializedUnitedArabEmirates.insertCountry()` to serialize and +store them to database, and call `SerializedChina.selectCountry()` and `serializedUnitedArabEmirates.selectCountry()` +methods to read and deserialize data items to `Country` objects. + +```java +@Slf4j +public class App { + private static final String DB_URL = "jdbc:h2:~/test"; + + private App() { + + } + + /** + * Program entry point. + * @param args command line args. + * @throws IOException if any + * @throws ClassNotFoundException if any + */ + public static void main(String[] args) throws IOException, ClassNotFoundException { + final var dataSource = createDataSource(); + + deleteSchema(dataSource); + createSchema(dataSource); + + final var China = new Country( + 86, + "China", + "Asia", + "Chinese" + ); + + final var UnitedArabEmirates = new Country( + 971, + "United Arab Emirates", + "Asia", + "Arabic" + ); + + final var serializedChina = new CountrySchemaSql(China, dataSource); + final var serializedUnitedArabEmirates = new CountrySchemaSql(UnitedArabEmirates, dataSource); + serializedChina.insertCountry(); + serializedUnitedArabEmirates.insertCountry(); + + serializedChina.selectCountry(); + serializedUnitedArabEmirates.selectCountry(); + } + + private static void deleteSchema(DataSource dataSource) { + try (var connection = dataSource.getConnection(); + var statement = connection.createStatement()) { + statement.execute(CountrySchemaSql.DELETE_SCHEMA_SQL); + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + } + + private static void createSchema(DataSource dataSource) { + try (var connection = dataSource.getConnection(); + var statement = connection.createStatement()) { + statement.execute(CountrySchemaSql.CREATE_SCHEMA_SQL); + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + } + + private static DataSource createDataSource() { + var dataSource = new JdbcDataSource(); + dataSource.setURL(DB_URL); + return dataSource; + } +} +``` + +## Class diagram + + +## Applicability + +Use the Serialized Entity pattern when + +* You want to easily persist Java objects to the database. + +## Related patterns +[Data Access Object](https://github.com/iluwatar/java-design-patterns/tree/master/dao) + +## Credits + +* [J2EE Design Patterns by William Crawford, Jonathan Kaplan](https://www.oreilly.com/library/view/j2ee-design-patterns/0596004273/re21.html) +* [komminen](https://github.com/komminen/java-design-patterns) (His attempts of serialized-entity inspired me and learned a lot from his code) diff --git a/serialized-entity/etc/serialize-entity.urm.puml b/serialized-entity/etc/serialize-entity.urm.puml new file mode 100644 index 000000000000..7bf89dbb98af --- /dev/null +++ b/serialized-entity/etc/serialize-entity.urm.puml @@ -0,0 +1,56 @@ +@startuml +package com.iluwatar.serializedentity { + class App { + - DB_URL : String {static} + - LOGGER : Logger {static} + + App() + - createDataSource() : DataSource {static} + - createSchema(dataSource : DataSource) {static} + - deleteSchema(dataSource : DataSource) {static} + + main(args : String[]) {static} + } + + class Country { + - code : int + - name : String + - continents : String + - language : String + + serialVersionUID : final Long {static} + ~Country(int, String, String, String) + + getCode() : int + + getName() : String + + getContinents() : String + + getLanguage() : String + + setCode(code : int) + + setName(name : String) + + setContinents(continents : String) + + setLanguage(language : String) + + equals(that: Object) : boolean + + hashCode() : int + + toString() : String + } + + interface CountryDao { + + insertCountry : int {abstract} + + selectCountry : int {abstract} + } + + class CountrySchemaSql { + - CREATE_SCHEMA_SQL : String {static} + - DELETE_SCHEMA_SQL : String {static} + - LOGGER : Logger {static} + - dataSource : DataSource + - country : Country + ~ CountrySchemaSql(country : Country, dataSource : DataSource) + + insertCountry() + + selectCountry() + } + diamond h2db +} + +App --> "Initialize Country objects" Country +App --> "Initialize CountrySchemaSql" CountrySchemaSql +CountrySchemaSql --> "implements" CountryDao +Country --> "Stored in database" h2db +CountrySchemaSql --> "Perform INSERT and SELECT operation after serialize and deserialize Country object" h2db +@enduml \ No newline at end of file diff --git a/serialized-entity/pom.xml b/serialized-entity/pom.xml new file mode 100644 index 000000000000..aea122f5a0ac --- /dev/null +++ b/serialized-entity/pom.xml @@ -0,0 +1,71 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + + The MIT License + Copyright © 2014-2022 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.26.0-SNAPSHOT</version> + </parent> + <artifactId>serialized-entity</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>org.mockito</groupId> + <artifactId>mockito-core</artifactId> + <scope>test</scope> + </dependency> + <dependency> + <groupId>com.h2database</groupId> + <artifactId>h2</artifactId> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.serializedentity.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> diff --git a/serialized-entity/src/main/java/com/iluwatar/serializedentity/App.java b/serialized-entity/src/main/java/com/iluwatar/serializedentity/App.java new file mode 100644 index 000000000000..fb3b383e69f7 --- /dev/null +++ b/serialized-entity/src/main/java/com/iluwatar/serializedentity/App.java @@ -0,0 +1,128 @@ +/* + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.serializedentity; + +import java.io.IOException; +import java.sql.SQLException; +import javax.sql.DataSource; +import lombok.extern.slf4j.Slf4j; +import org.h2.jdbcx.JdbcDataSource; + + +/** + * Serialized Entity Pattern. + * + * <p> Serialized Entity Pattern allow us to easily persist Java objects to the database. It uses Serializable interface + * and DAO pattern. Serialized Entity Pattern will first use Serializable to convert a Java object into a set of bytes, + * then it will using DAO pattern to store this set of bytes as BLOB to database.</p> + * + * <p> In this example, we first initialize two Java objects (Country) "China" and "UnitedArabEmirates", then we + * initialize "serializedChina" with "China" object and "serializedUnitedArabEmirates" with "UnitedArabEmirates", + * then we use method "serializedChina.insertCountry()" and "serializedUnitedArabEmirates.insertCountry()" to serialize + * "China" and "UnitedArabEmirates" and persist them to database. + * Last, with "serializedChina.selectCountry()" and "serializedUnitedArabEmirates.selectCountry()" we could read "China" + * and "UnitedArabEmirates" from database as sets of bytes, then deserialize them back to Java object (Country). </p> + * + */ +@Slf4j +public class App { + private static final String DB_URL = "jdbc:h2:~/test"; + + private App() { + + } + + /** + * Program entry point. + * @param args command line args. + * @throws IOException if any + * @throws ClassNotFoundException if any + */ + public static void main(String[] args) throws IOException, ClassNotFoundException { + final var dataSource = createDataSource(); + + deleteSchema(dataSource); + createSchema(dataSource); + + // Initializing Country Object China + final var China = new Country( + 86, + "China", + "Asia", + "Chinese" + ); + + // Initializing Country Object UnitedArabEmirates + final var UnitedArabEmirates = new Country( + 971, + "United Arab Emirates", + "Asia", + "Arabic" + ); + + // Initializing CountrySchemaSql Object with parameter "China" and "dataSource" + final var serializedChina = new CountrySchemaSql(China, dataSource); + // Initializing CountrySchemaSql Object with parameter "UnitedArabEmirates" and "dataSource" + final var serializedUnitedArabEmirates = new CountrySchemaSql(UnitedArabEmirates, dataSource); + + /* + By using CountrySchemaSql.insertCountry() method, the private (Country) type variable within Object + CountrySchemaSql will be serialized to a set of bytes and persist to database. + For more details of CountrySchemaSql.insertCountry() method please refer to CountrySchemaSql.java file + */ + serializedChina.insertCountry(); + serializedUnitedArabEmirates.insertCountry(); + + /* + By using CountrySchemaSql.selectCountry() method, CountrySchemaSql object will read the sets of bytes from database + and deserialize it to Country object. + For more details of CountrySchemaSql.selectCountry() method please refer to CountrySchemaSql.java file + */ + serializedChina.selectCountry(); + serializedUnitedArabEmirates.selectCountry(); + } + + private static void deleteSchema(DataSource dataSource) { + try (var connection = dataSource.getConnection(); + var statement = connection.createStatement()) { + statement.execute(CountrySchemaSql.DELETE_SCHEMA_SQL); + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + } + + private static void createSchema(DataSource dataSource) { + try (var connection = dataSource.getConnection(); + var statement = connection.createStatement()) { + statement.execute(CountrySchemaSql.CREATE_SCHEMA_SQL); + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + } + + private static DataSource createDataSource() { + var dataSource = new JdbcDataSource(); + dataSource.setURL(DB_URL); + return dataSource; + } +} diff --git a/serialized-entity/src/main/java/com/iluwatar/serializedentity/Country.java b/serialized-entity/src/main/java/com/iluwatar/serializedentity/Country.java new file mode 100644 index 000000000000..25ebddf89857 --- /dev/null +++ b/serialized-entity/src/main/java/com/iluwatar/serializedentity/Country.java @@ -0,0 +1,47 @@ +/* + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.serializedentity; +import java.io.Serializable; +import lombok.AllArgsConstructor; +import lombok.EqualsAndHashCode; +import lombok.Getter; +import lombok.Setter; +import lombok.ToString; + +/** + * A Country POJO taht represents the data that will serialize and store in database. + */ +@Getter +@Setter +@EqualsAndHashCode +@ToString +@AllArgsConstructor +public class Country implements Serializable { + + private int code; + private String name; + private String continents; + private String language; + public static final long serialVersionUID = 7149851; + +} diff --git a/serialized-entity/src/main/java/com/iluwatar/serializedentity/CountryDao.java b/serialized-entity/src/main/java/com/iluwatar/serializedentity/CountryDao.java new file mode 100644 index 000000000000..f5d91544672a --- /dev/null +++ b/serialized-entity/src/main/java/com/iluwatar/serializedentity/CountryDao.java @@ -0,0 +1,45 @@ +/* + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +/** + * In an application the Data Access Object (DAO) is a part of Data access layer. It is an object + * that provides an interface to some type of persistence mechanism. By mapping application calls to + * the persistence layer, DAO provides some specific data operations without exposing details of the + * database. This isolation supports the Single responsibility principle. It separates what data + * accesses the application needs, in terms of domain-specific objects and data types (the public + * interface of the DAO), from how these needs can be satisfied with a specific DBMS, database + * schema, etc. + * + * <p>Any change in the way data is stored and retrieved will not change the client code as the + * client will be using interface and need not worry about exact source. + * + * @see InMemoryCustomerDao + * @see DbCustomerDao + */ +package com.iluwatar.serializedentity; + +import java.io.IOException; + +public interface CountryDao { + int insertCountry() throws IOException; + int selectCountry() throws IOException, ClassNotFoundException; +} diff --git a/serialized-entity/src/main/java/com/iluwatar/serializedentity/CountrySchemaSql.java b/serialized-entity/src/main/java/com/iluwatar/serializedentity/CountrySchemaSql.java new file mode 100644 index 000000000000..4887ed9ddfd9 --- /dev/null +++ b/serialized-entity/src/main/java/com/iluwatar/serializedentity/CountrySchemaSql.java @@ -0,0 +1,122 @@ +/* + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.serializedentity; + +import java.io.ByteArrayInputStream; +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.ObjectInputStream; +import java.io.ObjectOutputStream; +import java.sql.Blob; +import java.sql.ResultSet; +import java.sql.SQLException; +import javax.sql.DataSource; + +import lombok.extern.slf4j.Slf4j; + +/** + * Country Schema SQL Class. + */ +@Slf4j +public class CountrySchemaSql implements CountryDao { + public static final String CREATE_SCHEMA_SQL = "CREATE TABLE IF NOT EXISTS WORLD (ID INT PRIMARY KEY, COUNTRY BLOB)"; + + public static final String DELETE_SCHEMA_SQL = "DROP TABLE WORLD IF EXISTS"; + + private Country country; + private DataSource dataSource; + + /** + * Public constructor. + * + * @param dataSource datasource + * @param country country + */ + public CountrySchemaSql(Country country, DataSource dataSource) { + this.country = new Country( + country.getCode(), + country.getName(), + country.getContinents(), + country.getLanguage() + ); + this.dataSource = dataSource; + } + + /** + * This method will serialize a Country object and store it to database. + * @return int type, if successfully insert a serialized object to database then return country code, else return -1. + * @throws IOException if any. + */ + @Override + public int insertCountry() throws IOException { + var sql = "INSERT INTO WORLD (ID, COUNTRY) VALUES (?, ?)"; + try (var connection = dataSource.getConnection(); + var preparedStatement = connection.prepareStatement(sql); + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + ObjectOutputStream oss = new ObjectOutputStream(baos)) { + + oss.writeObject(country); + oss.flush(); + + preparedStatement.setInt(1, country.getCode()); + preparedStatement.setBlob(2, new ByteArrayInputStream(baos.toByteArray())); + preparedStatement.execute(); + return country.getCode(); + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + return -1; + } + + /** + * This method will select a data item from database and deserialize it. + * @return int type, if successfully select and deserialized object from database then return country code, + * else return -1. + * @throws IOException if any. + * @throws ClassNotFoundException if any. + */ + @Override + public int selectCountry() throws IOException, ClassNotFoundException { + var sql = "SELECT ID, COUNTRY FROM WORLD WHERE ID = ?"; + try (var connection = dataSource.getConnection(); + var preparedStatement = connection.prepareStatement(sql)) { + + preparedStatement.setInt(1, country.getCode()); + + try (ResultSet rs = preparedStatement.executeQuery()) { + if (rs.next()) { + Blob countryBlob = rs.getBlob("country"); + ByteArrayInputStream baos = new ByteArrayInputStream(countryBlob.getBytes(1, (int) countryBlob.length())); + ObjectInputStream ois = new ObjectInputStream(baos); + country = (Country) ois.readObject(); + LOGGER.info("Country: " + country); + } + return rs.getInt("id"); + } + } catch (SQLException e) { + LOGGER.info("Exception thrown " + e.getMessage()); + } + return -1; + } + +} diff --git a/servant/pom.xml b/servant/pom.xml index 5e0b139154e3..65650364bd6b 100644 --- a/servant/pom.xml +++ b/servant/pom.xml @@ -27,6 +27,7 @@ --> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> + <groupId>servant</groupId> <parent> <groupId>com.iluwatar</groupId> <artifactId>java-design-patterns</artifactId>

diff --git a/serialized-entity/src/test/java/com/iluwatar/serializedentity/AppTest.java b/serialized-entity/src/test/java/com/iluwatar/serializedentity/AppTest.java new file mode 100644 index 000000000000..52ac9cd6e026 --- /dev/null +++ b/serialized-entity/src/test/java/com/iluwatar/serializedentity/AppTest.java @@ -0,0 +1,23 @@ +package com.iluwatar.serializedentity; + +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +/** + * Tests that Serialized Entity example runs without errors. + */ +class AppTest { + + /** + * Issue: Add at least one assertion to this test case. + * + * Solution: Inserted assertion to check whether the execution of the main method in {@link App#main(String[])} + * throws an exception. + */ + + @Test + void shouldExecuteSerializedEntityWithoutException() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} diff --git a/serialized-entity/src/test/java/com/iluwatar/serializedentity/CountryTest.java b/serialized-entity/src/test/java/com/iluwatar/serializedentity/CountryTest.java new file mode 100644 index 000000000000..85d3ed87fac2 --- /dev/null +++ b/serialized-entity/src/test/java/com/iluwatar/serializedentity/CountryTest.java @@ -0,0 +1,101 @@ +/* + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.serializedentity; +import org.junit.jupiter.api.Test; + +import java.io.*; + +import static org.junit.jupiter.api.Assertions.*; + +public class CountryTest { + + @Test + void testGetMethod() { + Country China = new Country( + 86, + "China", + "Asia", + "Chinese" + ); + + assertEquals(86, China.getCode()); + assertEquals("China", China.getName()); + assertEquals("Asia", China.getContinents()); + assertEquals("Chinese", China.getLanguage()); + } + + @Test + void testSetMethod() { + Country country = new Country( + 86, + "China", + "Asia", + "Chinese" + ); + + country.setCode(971); + country.setName("UAE"); + country.setContinents("West-Asia"); + country.setLanguage("Arabic"); + + assertEquals(971, country.getCode()); + assertEquals("UAE", country.getName()); + assertEquals("West-Asia", country.getContinents()); + assertEquals("Arabic", country.getLanguage()); + } + + @Test + void testSerializable(){ + // Serializing Country + try { + Country country = new Country( + 86, + "China", + "Asia", + "Chinese"); + ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("output.txt")); + objectOutputStream.writeObject(country); + objectOutputStream.close(); + } catch (IOException e) { + e.printStackTrace(); + } + + // De-serialize Country + try { + ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream("output.txt")); + Country country = (Country) objectInputStream.readObject(); + objectInputStream.close(); + System.out.println(country); + + Country China = new Country( + 86, + "China", + "Asia", + "Chinese"); + + assertEquals(China, country); + } catch (Exception e) { + e.printStackTrace(); + } + } +}

train

val

iluwatar

train

iluwatar/java-design-patterns/1288_2155

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1288

iluwatar/java-design-patterns/2155

9c4829ea56ebeaf54deda9445a0ef0a0ac3c269c

fd402fc876613282aaf855fd8fb5b92413af8522

Client Session State pattern

https://dzone.com/articles/practical-php-patterns/practical-php-patterns-client

diff --git a/client-session/README.md b/client-session/README.md new file mode 100644 index 000000000000..82204eb3495d --- /dev/null +++ b/client-session/README.md @@ -0,0 +1,114 @@ +--- +title: Client Session Pattern +category: Architectural +language: en +tags: +- Decoupling +--- + +## Name + +[Client Session pattern](https://dzone.com/articles/practical-php-patterns/practical-php-patterns-client) + +## Intent + +- Create stateless servers that removes the problem of clustering, as users can switch between servers seamlessly. +- Makes data more resilient in case of server fail-over. +- Works well with smaller data sizes. + +## Explanation + +Real-World Example + +> You're looking to create a data management app allowing users to send requests to the server to +> modify and make changes to data stored on their devices. These requests are small in size and the +> data is individual to each user, negating the need for a large scale database implementation. +> Using the client session pattern, you are able to handle multiple concurrent requests, load +> balancing clients across different servers with ease due to servers remaining stateless. You also +> remove the need to store session IDs on the server side due to clients providing all the +> information that a server needs to perform their process. + +In Plain words + +> Instead of storing information about the current client and the information being accessed on the +> server, it is maintained client side only. Client has to send session data with each request to +> the server and has to send an updated state back to the client, which is stored on the clients +> machine. The server doesn't have to store the client information. +> ([ref](https://dzone.com/articles/practical-php-patterns/practical-php-patterns-client)) + +**Programmatic Example** + +Here is the sample code to describe the client-session pattern. In the below code we are first +creating an instance of the Server. This server instance will then be used to get Session objects +for two clients. As you can see from the code below the Session object can be used to store any +relevant information that are required by the server to process the client request. These session +objects will then be passed on with every Request to the server. The Request will have the Session +object that stores the relevant client details along with the required data for processing the +request. The session information in every request helps the server identify the client and process +the request accordingly. + +```java +public class App { + + public static void main(String[] args) { + var server = new Server("localhost", 8080); + var session1 = server.getSession("Session1"); + var session2 = server.getSession("Session2"); + var request1 = new Request("Data1", session1); + var request2 = new Request("Data2", session2); + server.process(request1); + server.process(request2); + } +} + +@Data +@AllArgsConstructor +public class Session { + + /** + * Session id. + */ + private String id; + + /** + * Client name. + */ + private String clientName; + +} + +@Data +@AllArgsConstructor +public class Request { + + private String data; + + private Session session; + +} +``` + +## Architecture Diagram + + + +## Applicability + +Use the client state pattern when: + +- Processing smaller amounts of data to prevent larger requests and response sizes. +- Remove the need for servers to save client states. Doing so also removes the need to store session IDs. +- Clustering is an issue and needs to be avoided. Stateless servers allow clients to be easily distributed across servers. +- Creates resilience from data losses due to server fails. + +## Consequences + +- The server is stateless. Any compute API will not store any data. +- Struggles to deal with large amounts of data. Creates longer send and receive times due to larger amounts of session data to manage. +- Security. All data is stored on the client's machine. This means that any vulnerabilities on the clients side can expose all data being sent and received by the server. + + +## Credits + +- [Dzone - Practical PHP patterns](https://dzone.com/articles/practical-php-patterns/practical-php-patterns-client) +- [Client Session State Design Pattern - Ram N Java](https://www.youtube.com/watch?v=ycOSj9g41pc) diff --git a/client-session/pom.xml b/client-session/pom.xml new file mode 100644 index 000000000000..b7ff08637091 --- /dev/null +++ b/client-session/pom.xml @@ -0,0 +1,62 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + + The MIT License + Copyright © 2014-2022 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.26.0-SNAPSHOT</version> + </parent> + <artifactId>client-session</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.client.session.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> diff --git a/client-session/src/main/java/com/iluwatar/client/session/App.java b/client-session/src/main/java/com/iluwatar/client/session/App.java new file mode 100644 index 000000000000..282d8a7f3b28 --- /dev/null +++ b/client-session/src/main/java/com/iluwatar/client/session/App.java @@ -0,0 +1,55 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.client.session; + +/** + * The Client-Session pattern allows the session data to be stored on the client side and send this + * data to the server with each request. + * + * <p> In this example, The {@link Server} class represents the server that would process the + * incoming {@link Request} and also assign {@link Session} to a client. Here one instance of Server + * is created. The we create two sessions for two different clients. These sessions are then passed + * on to the server in the request along with the data. The server is then able to interpret the + * client based on the session associated with it. + * </p> + */ +public class App { + + /** + * Program entry point. + * + * @param args Command line args + */ + public static void main(String[] args) { + var server = new Server("localhost", 8080); + var session1 = server.getSession("Session1"); + var session2 = server.getSession("Session2"); + var request1 = new Request("Data1", session1); + var request2 = new Request("Data2", session2); + server.process(request1); + server.process(request2); + } +} diff --git a/client-session/src/main/java/com/iluwatar/client/session/Request.java b/client-session/src/main/java/com/iluwatar/client/session/Request.java new file mode 100644 index 000000000000..008011f180f7 --- /dev/null +++ b/client-session/src/main/java/com/iluwatar/client/session/Request.java @@ -0,0 +1,42 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.client.session; + +import lombok.AllArgsConstructor; +import lombok.Data; + +/** + * The Request class which contains the Session details and data. + */ +@Data +@AllArgsConstructor +public class Request { + + private String data; + + private Session session; + +} diff --git a/client-session/src/main/java/com/iluwatar/client/session/Server.java b/client-session/src/main/java/com/iluwatar/client/session/Server.java new file mode 100644 index 000000000000..6d9dc3dbc80a --- /dev/null +++ b/client-session/src/main/java/com/iluwatar/client/session/Server.java @@ -0,0 +1,65 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.client.session; + +import java.util.UUID; +import lombok.AllArgsConstructor; +import lombok.Data; +import lombok.extern.slf4j.Slf4j; + +/** + * The Server class. The client communicates with the server and request processing and getting a new session. + */ +@Slf4j +@Data +@AllArgsConstructor +public class Server { + private String host; + + private int port; + + + /** + * Creates a new session. + * + * @param name name of the client + * + * @return Session Object + */ + public Session getSession(String name) { + return new Session(UUID.randomUUID().toString(), name); + } + + /** + * Processes a request based on the session. + * + * @param request Request object with data and Session + */ + public void process(Request request) { + LOGGER.info("Processing Request with client: " + request.getSession().getClientName() + " data: " + request.getData()); + } + +} diff --git a/client-session/src/main/java/com/iluwatar/client/session/Session.java b/client-session/src/main/java/com/iluwatar/client/session/Session.java new file mode 100644 index 000000000000..bb9f7246cb4e --- /dev/null +++ b/client-session/src/main/java/com/iluwatar/client/session/Session.java @@ -0,0 +1,48 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.client.session; + +import lombok.AllArgsConstructor; +import lombok.Data; + +/** + * The Session class. Each client get assigned a Session which is then used for further communications. + */ +@Data +@AllArgsConstructor +public class Session { + + /** + * Session id. + */ + private String id; + + /** + * Client name. + */ + private String clientName; + +} diff --git a/pom.xml b/pom.xml index 09e4dea4fb70..90c4b29410bb 100644 --- a/pom.xml +++ b/pom.xml @@ -198,6 +198,7 @@ <module>composite-view</module> <module>metadata-mapping</module> <module>service-to-worker</module> + <module>client-session</module> <module>embedded-value</module> <module>currying</module> <module>serialized-entity</module>

diff --git a/client-session/src/test/java/com/iluwatar/client/session/AppTest.java b/client-session/src/test/java/com/iluwatar/client/session/AppTest.java new file mode 100644 index 000000000000..0e33f74f460b --- /dev/null +++ b/client-session/src/test/java/com/iluwatar/client/session/AppTest.java @@ -0,0 +1,38 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package com.iluwatar.client.session; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +import org.junit.jupiter.api.Test; + +class AppTest { + + @Test + void appStartsWithoutException() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} diff --git a/client-session/src/test/java/com/iluwatar/client/session/ServerTest.java b/client-session/src/test/java/com/iluwatar/client/session/ServerTest.java new file mode 100644 index 000000000000..dc09441f0a6a --- /dev/null +++ b/client-session/src/test/java/com/iluwatar/client/session/ServerTest.java @@ -0,0 +1,14 @@ +package com.iluwatar.client.session; + +import org.junit.jupiter.api.Test; +import static org.junit.jupiter.api.Assertions.assertEquals; + +class ServerTest { + + @Test + void checkGetSession() { + Server server = new Server("localhost", 8080); + Session session = server.getSession("Session"); + assertEquals("Session", session.getClientName()); + } +}

val

val

iluwatar

train

iluwatar/java-design-patterns/1762_2165

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1762

iluwatar/java-design-patterns/2165

4108f86177254b72cec4f05c3c2e0dab35e63536

13cb2e8d482d2e6505d8d68722625e5af220c40f

Ambiguity mapper pattern definition.

Ambiguity mapper pattern definition. Defining the mapper model for a specific problem case (fetching data) that produces a definition is not correct. we need an explanation on how/why to use this design template.

diff --git a/data-mapper/README.md b/data-mapper/README.md index 7766ca0b625c..b36414807612 100644 --- a/data-mapper/README.md +++ b/data-mapper/README.md @@ -3,21 +3,53 @@ title: Data Mapper category: Architectural language: en tags: - - Decoupling +- Decoupling --- ## Intent A layer of mappers that moves data between objects and a database while keeping them independent of each other and the mapper itself +This layer consists of one or more mappers (or data access objects) that perform data transfer. The scope of mapper implementations varies. +A generic mapper will handle many different domain entity types, a dedicated mapper will handle one or a few. + +## Explanation + +Real-world example + +> When accessing web resources through a browser, there is generally no need to interact with the server directly; +> the browser and the proxy server will complete the data acquisition operation, and the three will remain independent. + +In plain words + +> The data mapper will help complete the bi-directional transfer of persistence layer and in-memory data. + +Wikipedia says + +> A Data Mapper is a Data Access Layer that performs bidirectional transfer of data between a +> persistent data store (often a relational database) and an in-memory data representation (the domain layer). + +Programmatic example + ## Class diagram  ## Applicability Use the Data Mapper in any of the following situations -* when you want to decouple data objects from DB access layer +* when you want to decouple data objects from DB access layer * when you want to write multiple data retrieval/persistence implementations -## Credits +## Known uses +* [SqlSession.getMapper()](https://mybatis.org/mybatis-3/java-api.html) + +## Consequences -* [Data Mapper](http://richard.jp.leguen.ca/tutoring/soen343-f2010/tutorials/implementing-data-mapper/) +> Neatly mapped persistence layer data +> Data model follows the single function principle + +## Related patterns +* [Active Record Pattern](https://en.wikipedia.org/wiki/Active_record_pattern) +* [Object–relational Mapping](https://en.wikipedia.org/wiki/Object%E2%80%93relational_mapping) + +## Credits +* [Data Mapper](http://richard.jp.leguen.ca/tutoring/soen343-f2010/tutorials/implementing-data-mapper/) \ No newline at end of file

val

val

marouaneaba

train

iluwatar/java-design-patterns/2160_2171

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2160

iluwatar/java-design-patterns/2171

4108f86177254b72cec4f05c3c2e0dab35e63536

e063bd14e032fd1de78f17dc473a61642c76e75e

I'll translate the readme file of the proxy design pattern to Korean

I'll translate the readme file of the proxy design pattern to Korean and place it under localization/ko/proxy.

diff --git a/localization/ko/proxy/README.md b/localization/ko/proxy/README.md new file mode 100644 index 000000000000..95eb9dca992b --- /dev/null +++ b/localization/ko/proxy/README.md @@ -0,0 +1,160 @@ +--- +title: Proxy +category: Structural +language: ko +tags: +- Gang Of Four +- Decoupling +--- + +## 또한 ~으로 알려진 + +Surrogate + +## 의도 + +다른 객체에 대한 접근을 제어할 수 있는 대리인 또는 자리 표시자(placeholder)를 제공합니다. + +## 설명 + +실제 예제 + +> 지역 마법사들이 주문을 공부하러 가는 탑을 상상해 보세요. 상아탑은 프록시를 통해서만 접근할 수 있으며, 프록시는 처음 세 명의 마법사만 들어갈 수 있도록 합니다. 여기서 프록시는 타워의 기능을 나타내며 액세스 제어를 추가합니다. + +쉽게 말하자면 + +> 프록시 패턴을 사용하여, 클래스는 다른 클래스의 기능을 나타냅니다. + +Wikipedia에 의하면 + +> 프록시는 가장 일반적인 형태로 다른 것에 대한 인터페이스로서 기능하는 클래스이다. 프록시는 클라이언트가 백그라운드에서 실제 서비스 객체에 액세스하기 위해 호출하는 래퍼 또는 에이전트 객체입니다. 프록시의 사용은 단순히 실제 객체로 포워딩하거나 추가적인 논리를 제공할 수 있습니다. 프록시에서 실제 객체에 대한 작업이 리소스 집약적일 때, 캐싱하거나 실제 객체에 대한 작업이 호출되기 전에 사전 조건을 확인하는 등의 추가 기능이 제공될 수 있습니다. + +**코드 예제** + +위로부터 마법사 타워를 예로 들어보겠습니다. 먼저 `WiszrdTower` 인터페이스와 이를 구현한 +`IvoryTower` 클래스가 있습니다. + +```java +public interface WizardTower { + + void enter(Wizard wizard); +} + +@Slf4j +public class IvoryTower implements WizardTower { + + public void enter(Wizard wizard) { + LOGGER.info("{} enters the tower.", wizard); + } + +} +``` + +그리고 간단한 `Wizard` 클래스입니다. + + +```java +public class Wizard { + + private final String name; + + public Wizard(String name) { + this.name = name; + } + + @Override + public String toString() { + return name; + } +} +``` + +그리고 `WizardTower`에 대한 엑세스 통제를 추가하기 위해 `WizardTowerProxy`를 가집니다. + +```java +@Slf4j +public class WizardTowerProxy implements WizardTower { + + private static final int NUM_WIZARDS_ALLOWED = 3; + + private int numWizards; + + private final WizardTower tower; + + public WizardTowerProxy(WizardTower tower) { + this.tower = tower; + } + + @Override + public void enter(Wizard wizard) { + if (numWizards < NUM_WIZARDS_ALLOWED) { + tower.enter(wizard); + numWizards++; + } else { + LOGGER.info("{} is not allowed to enter!", wizard); + } + } +} +``` + +그리고 다음은 타워에 입장하는 시나리오입니다. + +```java +var proxy = new WizardTowerProxy(new IvoryTower()); +proxy.enter(new Wizard("Red wizard")); +proxy.enter(new Wizard("White wizard")); +proxy.enter(new Wizard("Black wizard")); +proxy.enter(new Wizard("Green wizard")); +proxy.enter(new Wizard("Brown wizard")); +``` + +프로그램 실행 결과: + +``` +Red wizard enters the tower. +White wizard enters the tower. +Black wizard enters the tower. +Green wizard is not allowed to enter! +Brown wizard is not allowed to enter! +``` + +## 클래스 다이어그램 + + + +## 적용 가능성 + +프록시는 단순한 포인터보다 더 다재다능하거나 정교한 오브젝트 참조가 필요할 때마다 적용할 수 있습니다. 다음은 프록시 패턴을 적용할 수 있는 몇 가지 일반적인 상황입니다. + + +* 원격 프록시는 다른 주소 공간에 있는 체의 로컬 대리자를 제공합니다. +* 가상 프록시는 요청 시 값비싼 개체를 생성합니다. +* 보호 프록시는 원래 객체에 대한 액세스를 제어합니다. 보호 프록시는 객체가 서로 다른 액세스 권한을 가져야 할 때 유용합니다. + +일반적으로 프록시 패턴은 다음과 같이 사용됩니다. + +* 다른 객체에 대한 액세스 제어 +* 지연 초기화 +* 로깅(logging) 구현 +* 네트워크 연결 촉진 +* 객체에 대한 참조 카운팅 + +## 튜토리얼 + +* [Controlling Access With Proxy Pattern](http://java-design-patterns.com/blog/controlling-access-with-proxy-pattern/) + +## 실제 사례 + +* [java.lang.reflect.Proxy](http://docs.oracle.com/javase/8/docs/api/java/lang/reflect/Proxy.html) +* [Apache Commons Proxy](https://commons.apache.org/proper/commons-proxy/) +* Mocking frameworks [Mockito](https://site.mockito.org/), + [Powermock](https://powermock.github.io/), [EasyMock](https://easymock.org/) + +## 관련 패턴 + +* [Ambassador](https://java-design-patterns.com/patterns/ambassador/) + +## 크레딧 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)

train

val

seongkyu-lim

train

iluwatar/java-design-patterns/2161_2172

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2161

iluwatar/java-design-patterns/2172

4108f86177254b72cec4f05c3c2e0dab35e63536

d9b4965eb94cf96693a765ebce7450a76f967836

I'll translate the readme file of the builder design pattern to Korean

I'll translate the readme file of the builder design pattern to Korean and place it under localization/ko/builder.

diff --git a/localization/ko/builder/README.md b/localization/ko/builder/README.md new file mode 100644 index 000000000000..25a93f5fe0fb --- /dev/null +++ b/localization/ko/builder/README.md @@ -0,0 +1,144 @@ +--- +title: Builder +category: Creational +language: ko +tags: +- Gang of Four +--- + +## 의도 + +동일한 구성 프로세스가 다른 표현을 생성할 수 있도록 복잡한 객체의 구성을 해당 표현과 분리합니다. + +## 설명 + +실제 예제 + +> 롤플레잉 게임의 캐릭터 생성기를 상상해 보세요. 가장 쉬운 옵션은 컴퓨터가 사용자를 위해 문자를 만들도록 하는 것입니다. 직업, 성별, 머리색 등 캐릭터 세부 정보를 수동으로 선택하려면 캐릭터 생성은 모든 선택이 준비되었을 때 완료되는 단계별 프로세스가 됩니다. + +쉽게 말하자면 + +> 생성자의 오염을 방지하면서 객체의 다른 맛들을 만들 수 있습니다. 여러 가지 맛의 객체가 있을 때 유용합니다. 또는 개체를 만드는 데 많은 단계가 수반될 때 유용합니다. + +Wikipedia에 의하면 + +> 빌더 패턴은 점층적 생성자 안티-패턴(telescoping constructor anti-pattern)에 대한 해결책을 찾기 위한 목적을 가진 객체 생성 소프트웨어 디자인 패턴이다. + +그렇긴 하지만, 점층적 생성자 안티-패턴(telescoping constructor anti-pattern)이 무엇인지 조금 더 설명하겠습니다. 어느 시점에서, 우리는 모두 다음과 같은 생성자를 보았습니다. + +```java +public Hero(Profession profession, String name, HairType hairType, HairColor hairColor, Armor armor, Weapon weapon) { +} +``` + +보시다시피 생성자 매개 변수의 수는 빠르게 감당할 수 없게 되고 매개 변수의 배치를 이해하는 것이 어려워질 수 있습니다. 또한 이 매개 변수 목록은 나중에 더 많은 옵션을 추가하려는 경우 계속 증가할 수 있습니다. 이를 점층적 생성자 안티-패턴(telescoping constructor anti-pattern)이라고 합니다. + +**코드 예제** + +올바른 대안은 빌더 패턴을 사용하는 것입니다. 우선, 우리는 우리가 창조하고 싶은 영웅을 가지고 있습니다. : + + +```java +public final class Hero { + private final Profession profession; + private final String name; + private final HairType hairType; + private final HairColor hairColor; + private final Armor armor; + private final Weapon weapon; + + private Hero(Builder builder) { + this.profession = builder.profession; + this.name = builder.name; + this.hairColor = builder.hairColor; + this.hairType = builder.hairType; + this.weapon = builder.weapon; + this.armor = builder.armor; + } +} +``` + +그리고 우리는 빌더를 가지고 있습니다. : + +```java + public static class Builder { + private final Profession profession; + private final String name; + private HairType hairType; + private HairColor hairColor; + private Armor armor; + private Weapon weapon; + + public Builder(Profession profession, String name) { + if (profession == null || name == null) { + throw new IllegalArgumentException("profession and name can not be null"); + } + this.profession = profession; + this.name = name; + } + + public Builder withHairType(HairType hairType) { + this.hairType = hairType; + return this; + } + + public Builder withHairColor(HairColor hairColor) { + this.hairColor = hairColor; + return this; + } + + public Builder withArmor(Armor armor) { + this.armor = armor; + return this; + } + + public Builder withWeapon(Weapon weapon) { + this.weapon = weapon; + return this; + } + + public Hero build() { + return new Hero(this); + } + } +``` + +그런 다음, 다음과 같이 사용할 수 있습니다. + + +```java +var mage = new Hero.Builder(Profession.MAGE, "Riobard").withHairColor(HairColor.BLACK).withWeapon(Weapon.DAGGER).build(); +``` + +## 클래스 다이어그램 + + + +## 적용 가능성 + +다음과 같은 경우 빌더 패턴을 사용합니다. + +* 복잡한 객체를 만드는 알고리즘은 객체를 구성하는 부품과 이들이 조립되는 방법에 독립적이어야 한다. +* 구축 프로세스는 구성된 객체에 대해 서로 다른 표현을 허용해야 합니다. + +## 튜토리얼 + +* [Refactoring Guru](https://refactoring.guru/design-patterns/builder) +* [Oracle Blog](https://blogs.oracle.com/javamagazine/post/exploring-joshua-blochs-builder-design-pattern-in-java) +* [Journal Dev](https://www.journaldev.com/1425/builder-design-pattern-in-java) + +## 실제 사례 + +* [java.lang.StringBuilder](http://docs.oracle.com/javase/8/docs/api/java/lang/StringBuilder.html) +* [java.nio.ByteBuffer](http://docs.oracle.com/javase/8/docs/api/java/nio/ByteBuffer.html#put-byte-) as well as similar buffers such as FloatBuffer, IntBuffer and so on. +* [java.lang.StringBuffer](http://docs.oracle.com/javase/8/docs/api/java/lang/StringBuffer.html#append-boolean-) +* All implementations of [java.lang.Appendable](http://docs.oracle.com/javase/8/docs/api/java/lang/Appendable.html) +* [Apache Camel builders](https://github.com/apache/camel/tree/0e195428ee04531be27a0b659005e3aa8d159d23/camel-core/src/main/java/org/apache/camel/builder) +* [Apache Commons Option.Builder](https://commons.apache.org/proper/commons-cli/apidocs/org/apache/commons/cli/Option.Builder.html) + +## 크레딧 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Effective Java](https://www.amazon.com/gp/product/0134685997/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0134685997&linkCode=as2&tag=javadesignpat-20&linkId=4e349f4b3ff8c50123f8147c828e53eb) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b) +* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7)

train

val

seongkyu-lim

train

iluwatar/java-design-patterns/2162_2173

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2162

iluwatar/java-design-patterns/2173

4108f86177254b72cec4f05c3c2e0dab35e63536

cfeee239570226f50b857770676686bc65b495df

I'll translate the readme file of the iterator design pattern to Korean

I'll translate the readme file of the iterator design pattern to Korean and place it under localization/ko/iterator. --- Contributing to the repo is almost my first contribution. And I realized that contributing to translation helped me a lot in my own learning. Thank you for creating this opportunity! @iluwatar

diff --git a/localization/ko/iterator/README.md b/localization/ko/iterator/README.md new file mode 100644 index 000000000000..54f2e564032e --- /dev/null +++ b/localization/ko/iterator/README.md @@ -0,0 +1,150 @@ +--- +title: Iterator +categories: Behavioral +language: ko +tags: +- Gang of Four +--- + +## 또한 ~으로 알려진 + +커서(Cursor) 패턴 + +## 의도 +기반이되는 표현을 노출하지 않고 Aggregate 객체의 요소에 순차적으로 접근할 수 있는 방법을 제공합니다. + +## 설명 + +실제 예제 + +> 보물상자에는 마법의 아이템이 들어 있습니다. 반지, 물약, 무기와 같은 다양한 종류의 물건들이 있습니다. 보물상자가 제공하는 반복기(iterator)를 사용하여 아이템은 유형별로 검색될 수 있을 것입니다. + +쉽게 말하자면 + +> 컨테이너는 요소에 대한 접근을 제공하기 위해 표현에 구애받지 않는 반복기(iterator) 인터페이스를 제공할 수 있습니다. + +Wikipedia에 의하면 + +> 반복자 패턴(iterator pattern)은 객체 지향 프로그래밍에서 반복자를 사용하여 컨테이너를 가로지르며 컨테이너의 요소들에 접근하는 디자인 패턴입니다. + +**코드 예제** + +예제의 메인 클래스는 아이템들을 담고있는 `보물상자(TreasureChest)` 입니다. + +```java +public class TreasureChest { + + private final List<Item> items; + + public TreasureChest() { + items = List.of( + new Item(ItemType.POTION, "Potion of courage"), + new Item(ItemType.RING, "Ring of shadows"), + new Item(ItemType.POTION, "Potion of wisdom"), + new Item(ItemType.POTION, "Potion of blood"), + new Item(ItemType.WEAPON, "Sword of silver +1"), + new Item(ItemType.POTION, "Potion of rust"), + new Item(ItemType.POTION, "Potion of healing"), + new Item(ItemType.RING, "Ring of armor"), + new Item(ItemType.WEAPON, "Steel halberd"), + new Item(ItemType.WEAPON, "Dagger of poison")); + } + + public Iterator<Item> iterator(ItemType itemType) { + return new TreasureChestItemIterator(this, itemType); + } + + public List<Item> getItems() { + return new ArrayList<>(items); + } +} +``` + +다음은 `아이템(item)` 클래스입니다. : + +```java +public class Item { + + private ItemType type; + private final String name; + + public Item(ItemType type, String name) { + this.setType(type); + this.name = name; + } + + @Override + public String toString() { + return name; + } + + public ItemType getType() { + return type; + } + + public final void setType(ItemType type) { + this.type = type; + } +} + +public enum ItemType { + + ANY, WEAPON, RING, POTION + +} +``` + +`반복자(Iterator)` 인터페이스는 아주 단순합니다. + +```java +public interface Iterator<T> { + + boolean hasNext(); + + T next(); +} +``` + +다음 예제에서는 보물상자에서 발견되는 고리형 항목을 반복한다. + +```java +var itemIterator = TREASURE_CHEST.iterator(ItemType.RING); +while (itemIterator.hasNext()) { + LOGGER.info(itemIterator.next().toString()); +} +``` + +프로그램 실행결과: + +```java +Ring of shadows +Ring of armor +``` + +## 클래스 다이어그램 + + + +## 적용 가능성 + +템플릿 메소드는 사용되어야합니다. + +* 내부 표현을 드러내지않고 aggregate 객체의 컨텐츠에 접근하기 위해서 + +* aggregate 오브젝트들의 여러 번의 횡단을 지원하기 위해서 + +* 서로 다른 aggregate 구조들의 횡단을 위한 획일적인 인터페이스를 제공하기 위해서 + +## 튜토리얼 + +* [How to Use Iterator?](http://www.tutorialspoint.com/java/java_using_iterator.htm) + +## 실제 사례 + +* [java.util.Iterator](http://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html) +* [java.util.Enumeration](http://docs.oracle.com/javase/8/docs/api/java/util/Enumeration.html) + +## 크레딧 + +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)

train

val

seongkyu-lim

train

iluwatar/java-design-patterns/1012_2175

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1012

iluwatar/java-design-patterns/2175

4108f86177254b72cec4f05c3c2e0dab35e63536

925996fcbde0465c2dcca5068a6a90420fcc8535

SonarCloud reports issues

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blockers and critical severity code smells (major, minor, and info level we ignore). In this task, those are fixed or marked as false positives. To mark false positives, SuppressWarnings annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity code smells in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=CODE_SMELL) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues) *** Note: When Submitting a PR please provide a **hyperlinked** list of all the issues that you are issuing a fix for. [_See this example_](https://github.com/iluwatar/java-design-patterns/pull/1833#issue-1015516036)

diff --git a/composite-view/src/main/java/com/iluwatar/compositeview/AppServlet.java b/composite-view/src/main/java/com/iluwatar/compositeview/AppServlet.java index 02aeab1b3497..7de1982a31bb 100644 --- a/composite-view/src/main/java/com/iluwatar/compositeview/AppServlet.java +++ b/composite-view/src/main/java/com/iluwatar/compositeview/AppServlet.java @@ -38,6 +38,7 @@ */ public final class AppServlet extends HttpServlet { + private static final String CONTENT_TYPE = "text/html"; private String msgPartOne = "<h1>This Server Doesn't Support"; private String msgPartTwo = "Requests</h1>\n" + "<h2>Use a GET request with boolean values for the following parameters<h2>\n" @@ -61,7 +62,7 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp) @Override public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { - resp.setContentType("text/html"); + resp.setContentType(CONTENT_TYPE); try (PrintWriter out = resp.getWriter()) { out.println(msgPartOne + " Post " + msgPartTwo); } @@ -71,7 +72,7 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) @Override public void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { - resp.setContentType("text/html"); + resp.setContentType(CONTENT_TYPE); try (PrintWriter out = resp.getWriter()) { out.println(msgPartOne + " Delete " + msgPartTwo); } @@ -80,7 +81,7 @@ public void doDelete(HttpServletRequest req, HttpServletResponse resp) @Override public void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { - resp.setContentType("text/html"); + resp.setContentType(CONTENT_TYPE); try (PrintWriter out = resp.getWriter()) { out.println(msgPartOne + " Put " + msgPartTwo); }

test

val

iluwatar

train

iluwatar/java-design-patterns/1012_2176

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1012

iluwatar/java-design-patterns/2176

4108f86177254b72cec4f05c3c2e0dab35e63536

6f21b1060767e6cbc222430f6f4eb5af3fd24226

SonarCloud reports issues

The project is using SonarCloud static code analysis. The latest results are showing that it has found several blockers and critical severity code smells (major, minor, and info level we ignore). In this task, those are fixed or marked as false positives. To mark false positives, SuppressWarnings annotation should be used in code as explained in the linked documentation. Links: [Blocker and critical severity code smells in SonarCloud](https://sonarcloud.io/project/issues?id=iluwatar_java-design-patterns&resolved=false&severities=BLOCKER%2CCRITICAL&types=CODE_SMELL) [Sonar false positives](https://docs.sonarqube.org/latest/analysis/languages/java/#JavaFAQ-HowtoremoveFalse-Positiveissues) *** Note: When Submitting a PR please provide a **hyperlinked** list of all the issues that you are issuing a fix for. [_See this example_](https://github.com/iluwatar/java-design-patterns/pull/1833#issue-1015516036)

diff --git a/special-case/src/main/java/com/iluwatar/specialcase/App.java b/special-case/src/main/java/com/iluwatar/specialcase/App.java index 43157d9ab395..5c6a10602543 100644 --- a/special-case/src/main/java/com/iluwatar/specialcase/App.java +++ b/special-case/src/main/java/com/iluwatar/specialcase/App.java @@ -37,6 +37,13 @@ public class App { private static final Logger LOGGER = LoggerFactory.getLogger(App.class); + private static final String LOGGER_STRING = "[REQUEST] User: {} buy product: {}"; + private static final String TEST_USER_1 = "ignite1771"; + private static final String TEST_USER_2 = "abc123"; + private static final String ITEM_TV = "tv"; + private static final String ITEM_CAR = "car"; + private static final String ITEM_COMPUTER = "computer"; + /** * Program entry point. */ @@ -44,28 +51,28 @@ public static void main(String[] args) { // DB seeding LOGGER.info("Db seeding: " + "1 user: {\"ignite1771\", amount = 1000.0}, " + "2 products: {\"computer\": price = 800.0, \"car\": price = 20000.0}"); - Db.getInstance().seedUser("ignite1771", 1000.0); - Db.getInstance().seedItem("computer", 800.0); - Db.getInstance().seedItem("car", 20000.0); + Db.getInstance().seedUser(TEST_USER_1, 1000.0); + Db.getInstance().seedItem(ITEM_COMPUTER, 800.0); + Db.getInstance().seedItem(ITEM_CAR, 20000.0); final var applicationServices = new ApplicationServicesImpl(); ReceiptViewModel receipt; - LOGGER.info("[REQUEST] User: " + "abc123" + " buy product: " + "tv"); - receipt = applicationServices.loggedInUserPurchase("abc123", "tv"); + LOGGER.info(LOGGER_STRING, TEST_USER_2, ITEM_TV); + receipt = applicationServices.loggedInUserPurchase(TEST_USER_2, ITEM_TV); receipt.show(); MaintenanceLock.getInstance().setLock(false); - LOGGER.info("[REQUEST] User: " + "abc123" + " buy product: " + "tv"); - receipt = applicationServices.loggedInUserPurchase("abc123", "tv"); + LOGGER.info(LOGGER_STRING, TEST_USER_2, ITEM_TV); + receipt = applicationServices.loggedInUserPurchase(TEST_USER_2, ITEM_TV); receipt.show(); - LOGGER.info("[REQUEST] User: " + "ignite1771" + " buy product: " + "tv"); - receipt = applicationServices.loggedInUserPurchase("ignite1771", "tv"); + LOGGER.info(LOGGER_STRING, TEST_USER_1, ITEM_TV); + receipt = applicationServices.loggedInUserPurchase(TEST_USER_1, ITEM_TV); receipt.show(); - LOGGER.info("[REQUEST] User: " + "ignite1771" + " buy product: " + "car"); - receipt = applicationServices.loggedInUserPurchase("ignite1771", "car"); + LOGGER.info(LOGGER_STRING, TEST_USER_1, ITEM_CAR); + receipt = applicationServices.loggedInUserPurchase(TEST_USER_1, ITEM_CAR); receipt.show(); - LOGGER.info("[REQUEST] User: " + "ignite1771" + " buy product: " + "computer"); - receipt = applicationServices.loggedInUserPurchase("ignite1771", "computer"); + LOGGER.info(LOGGER_STRING, TEST_USER_1, ITEM_COMPUTER); + receipt = applicationServices.loggedInUserPurchase(TEST_USER_1, ITEM_COMPUTER); receipt.show(); } }

val

val

iluwatar

train

iluwatar/java-design-patterns/2141_2186

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2141

iluwatar/java-design-patterns/2186

3dcda6f2457b27e4b0652ddd9f07e9c6b5b6d4c1

370d851ab0c9b5fb8448088c631953dbe1768699

Translate abstract-factory pattern to Vietnamese

I would like to translate `abstract-factory` pattern to Vietnamese and add it under `/localization/vi/` folder.

diff --git a/localization/vi/abstract-factory/README.md b/localization/vi/abstract-factory/README.md new file mode 100644 index 000000000000..25be6d86f860 --- /dev/null +++ b/localization/vi/abstract-factory/README.md @@ -0,0 +1,230 @@ +--- +title: Abstract Factory +category: Creational +language: vi +tags: + - Gang of Four +--- + +## Còn được biết đến như + +Kit + +## Mục tiêu + +Cung cấp giao diện (interface) để khởi tạo các đối tượng liên quan +hoặc có phụ thuộc mà không cần chỉ định các lớp cụ thể của chúng. + +## Giải thích + +Nhà Máy Trừu Tượng (thuật ngữ tiếng Anh: Abstract Factory). + +Ví dụ thực tế + +> Để tạo ra một vương quốc, chúng ta cần các đối tượng có chủ đề chung. Vương quốc Elf cần một vị vua Elf, lâu đài Elf và quân đội Elf trong khi vương quốc Orc cần một vị vua Orc, lâu đài Orc và quân đội Orc. Các đối tượng trong vương quốc phụ thuộc lẫn nhau. + +Một cách đơn giản + +> Một nhà máy của nhiều nhà máy; một nhà máy nhóm các nhà máy riêng lẻ nhưng có liên quan hoặc phụ thuộc lại với nhau mà không chỉ định các lớp cụ thể của chúng. + +Wikipedia viết (tạm dịch) + +> Mẫu Nhà Máy Trừu Tượng cung cấp cách làm để đóng gói một nhóm các nhà máy riêng lẻ có chủ đề chung mà không cần chỉ định các lớp cụ thể của chúng + +**Chương trình ví dụ** + +Sử dụng ví dụ về vương quốc đã nêu ở trên. +Trước hết, chúng ta có một số giao diện (interface) và lớp (class) được hiện thực hóa cho các đối tượng trong vương quốc. + +```java +public interface Castle { + String getDescription(); +} + +public interface King { + String getDescription(); +} + +public interface Army { + String getDescription(); +} + +// Hiện thực hóa tộc Elf -> +public class ElfCastle implements Castle { + static final String DESCRIPTION = "This is the elven castle!"; + @Override + public String getDescription() { + return DESCRIPTION; + } +} +public class ElfKing implements King { + static final String DESCRIPTION = "This is the elven king!"; + @Override + public String getDescription() { + return DESCRIPTION; + } +} +public class ElfArmy implements Army { + static final String DESCRIPTION = "This is the elven Army!"; + @Override + public String getDescription() { + return DESCRIPTION; + } +} + +// Tương tự, hiện thực hóa tộc Orc -> ... + +``` + +Sau đó, chúng ta có trừu tượng hóa và hiện thực hóa cho nhà máy vương quốc. + +```java +public interface KingdomFactory { + Castle createCastle(); + King createKing(); + Army createArmy(); +} + +public class ElfKingdomFactory implements KingdomFactory { + + @Override + public Castle createCastle() { + return new ElfCastle(); + } + + @Override + public King createKing() { + return new ElfKing(); + } + + @Override + public Army createArmy() { + return new ElfArmy(); + } +} + +public class OrcKingdomFactory implements KingdomFactory { + + @Override + public Castle createCastle() { + return new OrcCastle(); + } + + @Override + public King createKing() { + return new OrcKing(); + } + + @Override + public Army createArmy() { + return new OrcArmy(); + } +} +``` + +Bây giờ, chúng ta có Nhà Máy Trừu Tượng cho phép chúng ta tạo một nhóm các đối tượng liên quan, tức là nhà máy vương quốc Elf tạo ra lâu đài, vua và quân đội của tộc Elf, v.v. + +```java +var factory = new ElfKingdomFactory(); +var castle = factory.createCastle(); +var king = factory.createKing(); +var army = factory.createArmy(); + +castle.getDescription(); +king.getDescription(); +army.getDescription(); +``` + +Đầu ra khi chạy chương trình: + +```java +This is the elven castle! +This is the elven king! +This is the elven Army! +``` + +Bây giờ, chúng ta có thể thiết kế một nhà máy cho các nhà máy vương quốc khác nhau. Trong ví dụ này, chúng tôi đã tạo `FactoryMaker`, chịu trách nhiệm trả về một thể hiện của` ElfKingdomFactory` hoặc `OrcKingdomFactory`. +Người dùng có thể sử dụng `FactoryMaker` để tạo ra nhà máy mà họ mong muốn, sau đó, `FactoryMaker` sẽ tạo ra các đối tượng cụ thể (là dẫn xuất của `Army`, `King`, `Castle`). +Trong ví dụ này, chúng tôi cũng sử dụng một enum để tham số hóa các loại nhà máy vương quốc mà khách hàng sẽ yêu cầu. + +```java +public static class FactoryMaker { + + public enum KingdomType { + ELF, ORC + } + + public static KingdomFactory makeFactory(KingdomType type) { + switch (type) { + case ELF: + return new ElfKingdomFactory(); + case ORC: + return new OrcKingdomFactory(); + default: + throw new IllegalArgumentException("KingdomType not supported."); + } + } +} + +public static void main(String[] args) { + var app = new App(); + + LOGGER.info("Elf Kingdom"); + app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF)); + LOGGER.info(app.getArmy().getDescription()); + LOGGER.info(app.getCastle().getDescription()); + LOGGER.info(app.getKing().getDescription()); + + LOGGER.info("Orc Kingdom"); + app.createKingdom(FactoryMaker.makeFactory(KingdomType.ORC)); + -- Tương tự với nhà máy Orc +} +``` + +## Sơ đồ lớp + + + +## Ứng dụng +Sử dụng mẫu Nhà Máy Trừu Tượng khi + +* Hệ thống nên độc lập với cách mà nó khởi tạo/kết hợp/trình bày sản phẩm của nó. +* Hệ thống nên được cấu hình với một trong các họ sản phẩm. +* Họ của các đối tượng sản phẩm được thiết kế để sử dụng cùng nhau, và bạn cần áp đặt ràng buộc này. +* Bạn muốn cung cấp một thư viện lớp các sản phẩm, và bạn chỉ muốn tiết lộ giao diện (interface), ẩn giấu hiện thực hóa của chúng. +* Thời gian tồn tại của đối tượng phụ thuộc thì ngắn hơn thời gian tồn tại của đối tượng sử dụng. +* Bạn cần một/vài giá trị trong lúc chạy để khởi tạo một/vài đối tượng phụ thuộc cụ thể. +* Bạn muốn quyết định sản phẩm nào được gọi từ một họ trong lúc chạy. +* Bạn cần tính nhất quán giữa các sản phẩm. +* Bạn không muốn sửa mã nguồn khi thêm những sản phẩm mới hoặc họ của các sản phẩm vào chương trình. + +Ví dụ về ca sử dụng + +* Lựa chọn để gọi đến hiện thực hóa phù hợp của FileSystemAcmeService hoặc DatabaseAcmeService hoặc NetworkAcmeService trong lúc thực thi. +* Kiểm thử đơn vị trở nên cực kì dễ dàng. +* Công cụ giao diện cho các hệ điều hành khác nhau. + +## Hệ quả + +* Sự tiêm phụ thuộc (dependency injection) trong Java che đậy các lớp dịch vụ phụ thuộc nên nó có thể dẫn tới lỗi trong quá trình thực thi, điều mà lẽ ra có thể bắt được trong quá trình biên dịch. +* Trong khi mẫu này sử dụng hiệu quả với các đối tượng đã được định nghĩa sẵn, thêm một/vài đối tượng mới có thể sẽ khó khăn. +* Mã nguồn trở nên phức tạp hơn do nó có thêm giao diện (interface) và lớp (class) được giới thiệu đi kèm theo mẫu. + +## Hướng dẫn + +* [Abstract Factory Pattern Tutorial](https://www.journaldev.com/1418/abstract-factory-design-pattern-in-java) + +## Thông dụng + +* [javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html) +* [javax.xml.transform.TransformerFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/transform/TransformerFactory.html#newInstance--) +* [javax.xml.xpath.XPathFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/xpath/XPathFactory.html#newInstance--) + +## Mẫu liên quan + +* [Factory Method](https://java-design-patterns.com/patterns/factory-method/) +* [Factory Kit](https://java-design-patterns.com/patterns/factory-kit/) + +## Tham khảo +* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59) +* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)

test

val

m-inh

train

iluwatar/java-design-patterns/2187_2188

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2187

iluwatar/java-design-patterns/2188

3dcda6f2457b27e4b0652ddd9f07e9c6b5b6d4c1

3fde35ac77467c98c0ec4e89ed6638a18d95035d

Add lombok to MVC pattern

The pattern currently runs without lombok, I'm adding it so we can have the code more similar to new generation code

diff --git a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Fatigue.java b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Fatigue.java index 0cf9941ce4c3..00cced2407a2 100644 --- a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Fatigue.java +++ b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Fatigue.java @@ -24,9 +24,12 @@ */ package com.iluwatar.model.view.controller; +import lombok.AllArgsConstructor; + /** * Fatigue enumeration. */ +@AllArgsConstructor public enum Fatigue { ALERT("alert"), TIRED("tired"), @@ -34,9 +37,6 @@ public enum Fatigue { private final String title; - Fatigue(String title) { - this.title = title; - } @Override public String toString() { diff --git a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantModel.java b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantModel.java index e6206e065626..3de47cdcba6d 100644 --- a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantModel.java +++ b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantModel.java @@ -24,47 +24,26 @@ */ package com.iluwatar.model.view.controller; +import lombok.AllArgsConstructor; +import lombok.Builder; +import lombok.Getter; +import lombok.NoArgsConstructor; +import lombok.Setter; + /** * GiantModel contains the giant data. */ +@Getter +@Setter +@Builder +@AllArgsConstructor +@NoArgsConstructor public class GiantModel { private Health health; private Fatigue fatigue; private Nourishment nourishment; - /** - * Instantiates a new GiantModel. - */ - public GiantModel(Health health, Fatigue fatigue, Nourishment nourishment) { - this.health = health; - this.fatigue = fatigue; - this.nourishment = nourishment; - } - - public Health getHealth() { - return health; - } - - public void setHealth(Health health) { - this.health = health; - } - - public Fatigue getFatigue() { - return fatigue; - } - - public void setFatigue(Fatigue fatigue) { - this.fatigue = fatigue; - } - - public Nourishment getNourishment() { - return nourishment; - } - - public void setNourishment(Nourishment nourishment) { - this.nourishment = nourishment; - } @Override public String toString() { diff --git a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Health.java b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Health.java index 75b50a3486ea..0f54f5cd3825 100644 --- a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Health.java +++ b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Health.java @@ -24,9 +24,12 @@ */ package com.iluwatar.model.view.controller; +import lombok.AllArgsConstructor; + /** * Health enumeration. */ +@AllArgsConstructor public enum Health { HEALTHY("healthy"), WOUNDED("wounded"), @@ -34,9 +37,6 @@ public enum Health { private final String title; - Health(String title) { - this.title = title; - } @Override public String toString() { diff --git a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Nourishment.java b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Nourishment.java index e8ec91cf5710..f08a9c5bced3 100644 --- a/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Nourishment.java +++ b/model-view-controller/src/main/java/com/iluwatar/model/view/controller/Nourishment.java @@ -24,9 +24,12 @@ */ package com.iluwatar.model.view.controller; +import lombok.AllArgsConstructor; + /** * Nourishment enumeration. */ +@AllArgsConstructor public enum Nourishment { SATURATED("saturated"), HUNGRY("hungry"), @@ -34,9 +37,6 @@ public enum Nourishment { private final String title; - Nourishment(String title) { - this.title = title; - } @Override public String toString() {

train

val

burno1

train

iluwatar/java-design-patterns/2269_2270

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2269

iluwatar/java-design-patterns/2270

e4990df5816ca6c9f016e9a1414fe5d01f033183

f8a3d93f33b5c4150af4483db937ae7c05a2a545

Integrate stale bot

There is a handy [stale bot](https://github.com/probot/stale) that can monitor issues and pull requests and mark them as stale when nothing happens for a period of time. Let's integrate it in this issue. Acceptance criteria - Stale bot has been integrated into the repository

diff --git a/.github/stale.yml b/.github/stale.yml new file mode 100644 index 000000000000..f756aa30a3d0 --- /dev/null +++ b/.github/stale.yml @@ -0,0 +1,59 @@ +# Configuration for probot-stale - https://github.com/probot/stale + +# Number of days of inactivity before an Issue or Pull Request becomes stale +daysUntilStale: 30 + +# Number of days of inactivity before an Issue or Pull Request with the stale label is closed. +# Set to false to disable. If disabled, issues still need to be closed manually, but will remain marked as stale. +daysUntilClose: false + +# Only issues or pull requests with all of these labels are check if stale. Defaults to `[]` (disabled) +onlyLabels: [] + +# Issues or Pull Requests with these labels will never be considered stale. Set to `[]` to disable +exemptLabels: + - "info: help wanted" + +# Set to true to ignore issues in a project (defaults to false) +exemptProjects: false + +# Set to true to ignore issues in a milestone (defaults to false) +exemptMilestones: false + +# Set to true to ignore issues with an assignee (defaults to false) +exemptAssignees: false + +# Label to use when marking as stale +staleLabel: "status: stale" + +# Comment to post when marking as stale. Set to `false` to disable +markComment: > + This issue has been automatically marked as stale because it has not had + recent activity. It will be closed if no further activity occurs. Thank you + for your contributions. + +# Comment to post when removing the stale label. +# unmarkComment: > +# Your comment here. + +# Comment to post when closing a stale Issue or Pull Request. +# closeComment: > +# Your comment here. + +# Limit the number of actions per hour, from 1-30. Default is 30 +limitPerRun: 30 + +# Limit to only `issues` or `pulls` +# only: issues + +# Optionally, specify configuration settings that are specific to just 'issues' or 'pulls': +# pulls: +# daysUntilStale: 30 +# markComment: > +# This pull request has been automatically marked as stale because it has not had +# recent activity. It will be closed if no further activity occurs. Thank you +# for your contributions. + +# issues: +# exemptLabels: +# - confirmed \ No newline at end of file

val

val

iluwatar

train

iluwatar/java-design-patterns/1842_2271

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1842

iluwatar/java-design-patterns/2271

0793c50363d67851f88316e38f9b43144cec5ad7

7be2828c8ac7747e91107d71606cc82484039e92

Currying

I's a functional programming design pattern. As far as I understand you call a function with less parameters than usual and it can be used to defer processing when it has many steps involved. UML example ``` @startuml 'https://plantuml.com/class-diagram interface BiFunction <ParamType1, ParamType2, ResultType>{ } interface Curried<ParamType1, ParamType2 extends Simple> { +ParamType2 apply(final ParamType1 a); } interface Simple<ParamType1, ParamType2, ResultType> extends BiFunction { +ResultType apply(final ParamType1 a, final ParamType2 b); } @enduml ```  With the curried version you can do stuff like: ``` System.out.println(curriedAdd.apply(4).apply(5)); Function1<Integer, Integer> adder5 = curriedAdd.apply(5); //some complicate and time consuming process here System.out.println(adder5.apply(4)); System.out.println(adder5.apply(6)); ```

diff --git a/currying/README.md b/currying/README.md new file mode 100644 index 000000000000..72e0e89d46df --- /dev/null +++ b/currying/README.md @@ -0,0 +1,191 @@ +--- +title: Currying +category: Functional +language: en +tag: +- Decoupling +--- + +## Name / classification +Currying + +## Intent +Currying decomposes a function that takes multiple arguments into a sequence of functions that each take a single argument. +Curried functions are useful since they can be used to create new functions with lower arity to perform more specialised tasks +in a concise and readable manner. This is done via partial application. + +## Explanation +Real-world example +> Consider a librarian who wants to populate their library with books. The librarian wants functions which can create +> books corresponding to specific genres and authors. Currying makes this possible by writing a curried book builder +> function and utilising partial application. + +In plain words +> Decompose a function that take multiple arguments into multiple functions that take a single argument. + +Wikipedia says +> Currying is the technique of converting a function that takes multiple arguments into a sequence of functions that +> each take a single argument. Given a function $f:(X \times Y) \rightarrow Z$, currying constructs a new function +> $h:X \rightarrow (Y\rightarrow Z)$. $h$ takes an argument from $X$ and returns a function which maps $Y$ to $Z$. Hence, +> $h(x)(y) = f(x, y)$. + +Programmatic example +We have a `Book` class and `Genre` enum. +```java +public class Book { + private final Genre genre; + private final String author; + private final String title; + private final LocalDate publicationDate; + + Book(Genre genre, String author, String title, LocalDate publicationDate) { + this.genre = genre; + this.author = author; + this.title = title; + this.publicationDate = publicationDate; + } +} + +public enum Genre { + FANTASY, + HORROR, + SCI_FI; +} +``` +We could easily create a `Book` object with the following method: +```java +Book createBook(Genre genre, String author, String title, LocalDate publicationDate) { + return new Book(genre, author, title, publicationDate); +} +``` +However, what if we only wanted to create books from the `FANTASY` genre? We could pass in the `FANTASY` parameter on each method call; however, this is repetitive. We could define a new method specifically for creating `FANTASY` books; however, it is infeasible to create a new method for each book genre. The solution is to create a curried function. +```java +static Function<Genre, Function<String, Function<String, Function<LocalDate, Book>>>> book_creator + = genre + -> author + -> title + -> publicationDate + -> new Book(genre, author, title, publicationDate); +``` +Note that the order of the parameters is important. `genre` must come before `author`, `author` must come before `title` and so on. We must be considerate of this when writing curried functions to take full advantage of partial application. Using the above function, we can define a new function `fantasyBookFunc`, to generate `FANTASY` books as follows: +```java +Function<String, Function<String, Function<LocalDate, Book>>> fantasyBookFunc = Book.book_creator.apply(Genre.FANTASY); +``` +Unfortunately, the type signature of `BOOK_CREATOR` and `fantasyBookFunc` are difficult to read and understand. We can improve this by using the [builder pattern](https://java-design-patterns.com/patterns/builder/) and [functional interfaces](https://www.geeksforgeeks.org/functional-interfaces-java/#:~:text=A%20functional%20interface%20is%20an,any%20number%20of%20default%20methods). +```java +public static AddGenre builder() { + return genre + -> author + -> title + -> publicationDate + -> new Book(genre, author, title, publicationDate); +} + +public interface AddGenre { +Book.AddAuthor withGenre(Genre genre); +} + +public interface AddAuthor { +Book.AddTitle withAuthor(String author); +} + +public interface AddTitle { +Book.AddPublicationDate withTitle(String title); +} + +public interface AddPublicationDate { +Book withPublicationDate(LocalDate publicationDate); +} +``` +The semantics of the `builder` function can easily be understood. The `builder` function returns a function `AddGenre`, which adds the genre to the book. Similarity, the `AddGenre` function returns another function `AddTitle`, which adds the title to the book and so on, until the `AddPublicationDate` function returns a `Book`. +For example, we could create a `Book` as follows: +```java +Book book = Book.builder().withGenre(Genre.FANTAST) + .withAuthor("Author") + .withTitle("Title") + .withPublicationDate(LocalDate.of(2000, 7, 2)); +``` +The below example demonstrates how partial application can be used with the `builder` function to create specialised book builder functions. +```java +public static void main(String[] args) { + LOGGER.info("Librarian begins their work."); + + // Defining genre book functions + Book.AddAuthor fantasyBookFunc = Book.builder().withGenre(Genre.FANTASY); + Book.AddAuthor horrorBookFunc = Book.builder().withGenre(Genre.HORROR); + Book.AddAuthor scifiBookFunc = Book.builder().withGenre(Genre.SCI_FI); + + // Defining author book functions + Book.AddTitle kingFantasyBooksFunc = fantasyBookFunc.withAuthor("Stephen King"); + Book.AddTitle kingHorrorBooksFunc = horrorBookFunc.withAuthor("Stephen King"); + Book.AddTitle rowlingFantasyBooksFunc = fantasyBookFunc.withAuthor("J.K. Rowling"); + + // Creates books by Stephen King (horror and fantasy genres) + Book shining = kingHorrorBooksFunc.withTitle("The Shining") + .withPublicationDate(LocalDate.of(1977, 1, 28)); + Book darkTower = kingFantasyBooksFunc.withTitle("The Dark Tower: Gunslinger") + .withPublicationDate(LocalDate.of(1982, 6, 10)); + + // Creates fantasy books by J.K. Rowling + Book chamberOfSecrets = rowlingFantasyBooksFunc.withTitle("Harry Potter and the Chamber of Secrets") + .withPublicationDate(LocalDate.of(1998, 7, 2)); + + // Create sci-fi books + Book dune = scifiBookFunc.withAuthor("Frank Herbert") + .withTitle("Dune") + .withPublicationDate(LocalDate.of(1965, 8, 1)); + Book foundation = scifiBookFunc.withAuthor("Isaac Asimov") + .withTitle("Foundation") + .withPublicationDate(LocalDate.of(1942, 5, 1)); + + LOGGER.info("Stephen King Books:"); + LOGGER.info(shining.toString()); + LOGGER.info(darkTower.toString()); + + LOGGER.info("J.K. Rowling Books:"); + LOGGER.info(chamberOfSecrets.toString()); + + LOGGER.info("Sci-fi Books:"); + LOGGER.info(dune.toString()); + LOGGER.info(foundation.toString()); +} +``` +Program output: +``` +Librarian begins their work. +Stephen King Books: +Book{genre=HORROR, author='Stephen King', title='The Shining', publicationDate=1977-01-28} +Book{genre=FANTASY, author='Stephen King', title='The Dark Tower: Gunslinger', publicationDate=1982-06-10} +J.K. Rowling Books: +Book{genre=FANTASY, author='J.K. Rowling', title='Harry Potter and the Chamber of Secrets', publicationDate=1998-07-02} +Sci-fi Books: +Book{genre=SCI_FI, author='Frank Herbert', title='Dune', publicationDate=1965-08-01} +Book{genre=SCI_FI, author='Isaac Asimov', title='Foundation', publicationDate=1942-05-01} +``` + +## Class diagram + + +## Applicability +A curried function which has only been passed some of its arguments is called a partial application. Partial application +allows for the creation of functions with some pre-defined data in their scope, since partial application can be used to +create specialised functions with lower arity. This abstraction can help keep code readable and concise. Therefore, currying is useful when frequently calling functions with fixed parameters. + +## Known uses +Most functional programming languages support curried functions. A popular example is [Haskell](https://www.haskell.org/), in which all functions are considered curried. + +## Consequences +Pros +* Currying allows for partial application, which can be used to create specialised functions concisely. + +Cons +* The order of the parameters in a curried function is important since we want to take advantage of partial application. It is best to input the most general parameters first and input specific parameters last. +* As shown in the programmatic example above, curried functions with several parameters have a cumbersome type signature (in Java). + +## Related patterns +* [Builder patter](https://java-design-patterns.com/patterns/builder/) + +## Credits +* [Currying in Java](https://www.baeldung.com/java-currying) +* [What Is Currying in Programming](https://towardsdatascience.com/what-is-currying-in-programming-56fd57103431#:~:text=Currying%20is%20helpful%20when%20you,concise%2C%20and%20more%20readable%20solution.) +* [Why the fudge should I use currying?](https://medium.com/dailyjs/why-the-fudge-should-i-use-currying-84e4000c8743) \ No newline at end of file diff --git a/currying/etc/currying.urm.puml b/currying/etc/currying.urm.puml new file mode 100644 index 000000000000..9b336ff90828 --- /dev/null +++ b/currying/etc/currying.urm.puml @@ -0,0 +1,39 @@ +@startuml +package com.iluwatar.currying { + class App { + + App() + + main(args : String[]) {static} + } + class Book { + ~ BOOK_CREATOR : Function<Genre, Function<String, Function<String, Function<LocalDate, Book>>>> {static} + - author : String + - genre : Genre + - publicationDate : LocalDate + - title : String + ~ Book(genre : Genre, author : String, title : String, publicationDate : LocalDate) + + builder() : AddGenre {static} + } + interface AddAuthor { + + withAuthor(String) : AddTitle {abstract} + } + interface AddGenre { + + withGenre(Genre) : AddAuthor {abstract} + } + interface AddPublicationDate { + + withPublicationDate(LocalDate) : Book {abstract} + } + interface AddTitle { + + withTitle(String) : AddPublicationDate {abstract} + } + enum Genre { + + FANTASY {static} + + HORROR {static} + + SCI_FI {static} + } +} +Book --> "-genre" Genre +AddPublicationDate ..+ Book +AddAuthor ..+ Book +AddTitle ..+ Book +AddGenre ..+ Book +@enduml \ No newline at end of file diff --git a/currying/pom.xml b/currying/pom.xml new file mode 100644 index 000000000000..5b5385c45a59 --- /dev/null +++ b/currying/pom.xml @@ -0,0 +1,66 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + + The MIT License + Copyright © 2014-2022 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.26.0-SNAPSHOT</version> + </parent> + <artifactId>currying</artifactId> + <dependencies> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <!-- Maven assembly plugin is invoked with default setting which we have + in parent pom and specifying the class having main method --> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.currying.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> \ No newline at end of file diff --git a/currying/src/main/java/com/iluwatar/currying/App.java b/currying/src/main/java/com/iluwatar/currying/App.java new file mode 100644 index 000000000000..d3ca262b56c4 --- /dev/null +++ b/currying/src/main/java/com/iluwatar/currying/App.java @@ -0,0 +1,86 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.currying; + +import java.time.LocalDate; +import lombok.extern.slf4j.Slf4j; + +/** +* Currying decomposes a function with multiple arguments in multiple functions that +* take a single argument. A curried function which has only been passed some of its +* arguments is called a partial application. Partial application is useful since it can +* be used to create specialised functions in a concise way. +* +* <p>In this example, a librarian uses a curried book builder function create books belonging to +* desired genres and written by specific authors. +*/ +@Slf4j +public class App { + /** + * Main entry point of the program. + */ + public static void main(String[] args) { + LOGGER.info("Librarian begins their work."); + + // Defining genre book functions + Book.AddAuthor fantasyBookFunc = Book.builder().withGenre(Genre.FANTASY); + Book.AddAuthor horrorBookFunc = Book.builder().withGenre(Genre.HORROR); + Book.AddAuthor scifiBookFunc = Book.builder().withGenre(Genre.SCIFI); + + // Defining author book functions + Book.AddTitle kingFantasyBooksFunc = fantasyBookFunc.withAuthor("Stephen King"); + Book.AddTitle kingHorrorBooksFunc = horrorBookFunc.withAuthor("Stephen King"); + Book.AddTitle rowlingFantasyBooksFunc = fantasyBookFunc.withAuthor("J.K. Rowling"); + + // Creates books by Stephen King (horror and fantasy genres) + Book shining = kingHorrorBooksFunc.withTitle("The Shining") + .withPublicationDate(LocalDate.of(1977, 1, 28)); + Book darkTower = kingFantasyBooksFunc.withTitle("The Dark Tower: Gunslinger") + .withPublicationDate(LocalDate.of(1982, 6, 10)); + + // Creates fantasy books by J.K. Rowling + Book chamberOfSecrets = rowlingFantasyBooksFunc.withTitle("Harry Potter and the Chamber of Secrets") + .withPublicationDate(LocalDate.of(1998, 7, 2)); + + // Create sci-fi books + Book dune = scifiBookFunc.withAuthor("Frank Herbert") + .withTitle("Dune") + .withPublicationDate(LocalDate.of(1965, 8, 1)); + Book foundation = scifiBookFunc.withAuthor("Isaac Asimov") + .withTitle("Foundation") + .withPublicationDate(LocalDate.of(1942, 5, 1)); + + LOGGER.info("Stephen King Books:"); + LOGGER.info(shining.toString()); + LOGGER.info(darkTower.toString()); + + LOGGER.info("J.K. Rowling Books:"); + LOGGER.info(chamberOfSecrets.toString()); + + LOGGER.info("Sci-fi Books:"); + LOGGER.info(dune.toString()); + LOGGER.info(foundation.toString()); + } +} \ No newline at end of file diff --git a/currying/src/main/java/com/iluwatar/currying/Book.java b/currying/src/main/java/com/iluwatar/currying/Book.java new file mode 100644 index 000000000000..f9b7be05138a --- /dev/null +++ b/currying/src/main/java/com/iluwatar/currying/Book.java @@ -0,0 +1,117 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.currying; + +import java.time.LocalDate; +import java.util.Objects; +import java.util.function.Function; +import lombok.AllArgsConstructor; + +/** + * Book class. + */ +@AllArgsConstructor +public class Book { + private final Genre genre; + private final String author; + private final String title; + private final LocalDate publicationDate; + + @Override + public boolean equals(Object o) { + if (this == o) { + return true; + } + if (o == null || getClass() != o.getClass()) { + return false; + } + Book book = (Book) o; + return Objects.equals(author, book.author) + && Objects.equals(genre, book.genre) + && Objects.equals(title, book.title) + && Objects.equals(publicationDate, book.publicationDate); + } + + @Override + public int hashCode() { + return Objects.hash(author, genre, title, publicationDate); + } + + @Override + public String toString() { + return "Book{" + "genre=" + genre + ", author='" + author + '\'' + + ", title='" + title + '\'' + ", publicationDate=" + publicationDate + '}'; + } + + /** + * Curried book builder/creator function. + */ + static Function<Genre, Function<String, Function<String, Function<LocalDate, Book>>>> book_creator + = bookGenre + -> bookAuthor + -> bookTitle + -> bookPublicationDate + -> new Book(bookGenre, bookAuthor, bookTitle, bookPublicationDate); + + /** + * Implements the builder pattern using functional interfaces to create a more readable book + * creator function. This function is equivalent to the BOOK_CREATOR function. + */ + public static AddGenre builder() { + return genre + -> author + -> title + -> publicationDate + -> new Book(genre, author, title, publicationDate); + } + + /** + * Functional interface which adds the genre to a book. + */ + public interface AddGenre { + Book.AddAuthor withGenre(Genre genre); + } + + /** + * Functional interface which adds the author to a book. + */ + public interface AddAuthor { + Book.AddTitle withAuthor(String author); + } + + /** + * Functional interface which adds the title to a book. + */ + public interface AddTitle { + Book.AddPublicationDate withTitle(String title); + } + + /** + * Functional interface which adds the publication date to a book. + */ + public interface AddPublicationDate { + Book withPublicationDate(LocalDate publicationDate); + } +} \ No newline at end of file diff --git a/currying/src/main/java/com/iluwatar/currying/Genre.java b/currying/src/main/java/com/iluwatar/currying/Genre.java new file mode 100644 index 000000000000..58e639f4ce3c --- /dev/null +++ b/currying/src/main/java/com/iluwatar/currying/Genre.java @@ -0,0 +1,34 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.currying; + +/** + * Enum representing different book genres. + */ +public enum Genre { + FANTASY, + HORROR, + SCIFI; +} diff --git a/pom.xml b/pom.xml index b75a4551ff13..be6a09f4c9cc 100644 --- a/pom.xml +++ b/pom.xml @@ -200,6 +200,7 @@ <module>composite-view</module> <module>metadata-mapping</module> <module>service-to-worker</module> + <module>currying</module> <module>serialized-entity</module> <module>identity-map</module> <module>component</module>

diff --git a/currying/src/test/java/com/iluwatar/currying/AppTest.java b/currying/src/test/java/com/iluwatar/currying/AppTest.java new file mode 100644 index 000000000000..83fd99363e52 --- /dev/null +++ b/currying/src/test/java/com/iluwatar/currying/AppTest.java @@ -0,0 +1,39 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.currying; + +import static org.junit.jupiter.api.Assertions.*; + +import org.junit.jupiter.api.Test; + +/** + * Tests that the App can be run without throwing any exceptions. + */ +class AppTest { + @Test + void executesWithoutExceptions() { + assertDoesNotThrow(() -> App.main(new String[]{})); + } +} diff --git a/currying/src/test/java/com/iluwatar/currying/BookCurryingTest.java b/currying/src/test/java/com/iluwatar/currying/BookCurryingTest.java new file mode 100644 index 000000000000..437941583618 --- /dev/null +++ b/currying/src/test/java/com/iluwatar/currying/BookCurryingTest.java @@ -0,0 +1,83 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.currying; + +import static org.junit.jupiter.api.Assertions.*; + +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; + +import java.time.LocalDate; + +/** + * Unit tests for the Book class + */ +class BookCurryingTest { + private static Book expectedBook; + + @BeforeAll + public static void initialiseBook() { + expectedBook = new Book(Genre.FANTASY, + "Dave", + "Into the Night", + LocalDate.of(2002, 4, 7)); + } + + /** + * Tests that the expected book can be created via curried functions + */ + @Test + void createsExpectedBook() { + Book builderCurriedBook = Book.builder() + .withGenre(Genre.FANTASY) + .withAuthor("Dave") + .withTitle("Into the Night") + .withPublicationDate(LocalDate.of(2002, 4, 7)); + + Book funcCurriedBook = Book.book_creator + .apply(Genre.FANTASY) + .apply("Dave") + .apply("Into the Night") + .apply(LocalDate.of(2002, 4, 7)); + + assertEquals(expectedBook, builderCurriedBook); + assertEquals(expectedBook, funcCurriedBook); + } + + /** + * Tests that an intermediate curried function can be used to create the expected book + */ + @Test + void functionCreatesExpectedBook() { + Book.AddTitle daveFantasyBookFunc = Book.builder() + .withGenre(Genre.FANTASY) + .withAuthor("Dave"); + + Book curriedBook = daveFantasyBookFunc.withTitle("Into the Night") + .withPublicationDate(LocalDate.of(2002, 4, 7)); + + assertEquals(expectedBook, curriedBook); + } +}

val

val

javatlacati

train

iluwatar/java-design-patterns/2242_2302

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2242

iluwatar/java-design-patterns/2302

cfeee239570226f50b857770676686bc65b495df

24bd93999d1acd583fc4c866b41dd363b2cb1616

Explanation for Model-View-Controller

In this issue, let's add a proper explanation for the pattern. Acceptance criteria - The pattern's README.md has been amended with an explanation - The explanation consists of - Real world example - In plain words - Wikipedia says - Programmatic example

diff --git a/model-view-controller/README.md b/model-view-controller/README.md index a94fb56c12b1..f4d2be8d8471 100644 --- a/model-view-controller/README.md +++ b/model-view-controller/README.md @@ -12,6 +12,132 @@ the model, the view and the controller. Let the model manage the data, the view display the data and the controller mediate updating the data and redrawing the display. +## Explanation + +Real-world example + +> Consider ICU room in hospital which displays the patients health information on device displays which +> are taking input from sensors connected to patient. Here, display's job is to display the data that +> it receives from the controller which in turn gets update from sensor model. + +In plain words + +> MVC separates the business logic from user interface by mediating Controller between Model & View. + +Wikipedia says + +> Model–view–controller (MVC) is commonly used for developing user interfaces that divide the +> related program logic into three interconnected elements. This is done to separate internal +> representations of information from the ways information is presented to and accepted from the user. + +**Programmatic Example** + +Consider following `GiantModel` model class that provides the health, fatigue & nourishment information. + +```java +public class GiantModel { + + private Health health; + private Fatigue fatigue; + private Nourishment nourishment; + + /** + * Instantiates a new GiantModel. + */ + public GiantModel(Health health, Fatigue fatigue, Nourishment nourishment) { + this.health = health; + this.fatigue = fatigue; + this.nourishment = nourishment; + } + + public Health getHealth() { + return health; + } + + public void setHealth(Health health) { + this.health = health; + } + + public Fatigue getFatigue() { + return fatigue; + } + + public void setFatigue(Fatigue fatigue) { + this.fatigue = fatigue; + } + + public Nourishment getNourishment() { + return nourishment; + } + + public void setNourishment(Nourishment nourishment) { + this.nourishment = nourishment; + } + + @Override + public String toString() { + return String.format("The giant looks %s, %s and %s.", health, fatigue, nourishment); + } +} +``` + +`GiantView` class to display received patient data. + +```java +public class GiantView { + + public void displayGiant(GiantModel giant) { + LOGGER.info(giant.toString()); + } +} +``` + +And `GiantController` class that takes updates from `GiantModel` & sends to `GiantView` for display. + +```java +public class GiantController { + + private final GiantModel giant; + private final GiantView view; + + public GiantController(GiantModel giant, GiantView view) { + this.giant = giant; + this.view = view; + } + + @SuppressWarnings("UnusedReturnValue") + public Health getHealth() { + return giant.getHealth(); + } + + public void setHealth(Health health) { + this.giant.setHealth(health); + } + + @SuppressWarnings("UnusedReturnValue") + public Fatigue getFatigue() { + return giant.getFatigue(); + } + + public void setFatigue(Fatigue fatigue) { + this.giant.setFatigue(fatigue); + } + + @SuppressWarnings("UnusedReturnValue") + public Nourishment getNourishment() { + return giant.getNourishment(); + } + + public void setNourishment(Nourishment nourishment) { + this.giant.setNourishment(nourishment); + } + + public void updateView() { + this.view.displayGiant(giant); + } +} +``` + ## Class diagram 

test

val

iluwatar

train

iluwatar/java-design-patterns/2243_2302

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2243

iluwatar/java-design-patterns/2302

cfeee239570226f50b857770676686bc65b495df

24bd93999d1acd583fc4c866b41dd363b2cb1616

Explanation for Model-View-Presenter

In this issue, let's add a proper explanation for the pattern. Acceptance criteria - The pattern's README.md has been amended with an explanation - The explanation consists of - Real world example - In plain words - Wikipedia says - Programmatic example

diff --git a/model-view-controller/README.md b/model-view-controller/README.md index a94fb56c12b1..f4d2be8d8471 100644 --- a/model-view-controller/README.md +++ b/model-view-controller/README.md @@ -12,6 +12,132 @@ the model, the view and the controller. Let the model manage the data, the view display the data and the controller mediate updating the data and redrawing the display. +## Explanation + +Real-world example + +> Consider ICU room in hospital which displays the patients health information on device displays which +> are taking input from sensors connected to patient. Here, display's job is to display the data that +> it receives from the controller which in turn gets update from sensor model. + +In plain words + +> MVC separates the business logic from user interface by mediating Controller between Model & View. + +Wikipedia says + +> Model–view–controller (MVC) is commonly used for developing user interfaces that divide the +> related program logic into three interconnected elements. This is done to separate internal +> representations of information from the ways information is presented to and accepted from the user. + +**Programmatic Example** + +Consider following `GiantModel` model class that provides the health, fatigue & nourishment information. + +```java +public class GiantModel { + + private Health health; + private Fatigue fatigue; + private Nourishment nourishment; + + /** + * Instantiates a new GiantModel. + */ + public GiantModel(Health health, Fatigue fatigue, Nourishment nourishment) { + this.health = health; + this.fatigue = fatigue; + this.nourishment = nourishment; + } + + public Health getHealth() { + return health; + } + + public void setHealth(Health health) { + this.health = health; + } + + public Fatigue getFatigue() { + return fatigue; + } + + public void setFatigue(Fatigue fatigue) { + this.fatigue = fatigue; + } + + public Nourishment getNourishment() { + return nourishment; + } + + public void setNourishment(Nourishment nourishment) { + this.nourishment = nourishment; + } + + @Override + public String toString() { + return String.format("The giant looks %s, %s and %s.", health, fatigue, nourishment); + } +} +``` + +`GiantView` class to display received patient data. + +```java +public class GiantView { + + public void displayGiant(GiantModel giant) { + LOGGER.info(giant.toString()); + } +} +``` + +And `GiantController` class that takes updates from `GiantModel` & sends to `GiantView` for display. + +```java +public class GiantController { + + private final GiantModel giant; + private final GiantView view; + + public GiantController(GiantModel giant, GiantView view) { + this.giant = giant; + this.view = view; + } + + @SuppressWarnings("UnusedReturnValue") + public Health getHealth() { + return giant.getHealth(); + } + + public void setHealth(Health health) { + this.giant.setHealth(health); + } + + @SuppressWarnings("UnusedReturnValue") + public Fatigue getFatigue() { + return giant.getFatigue(); + } + + public void setFatigue(Fatigue fatigue) { + this.giant.setFatigue(fatigue); + } + + @SuppressWarnings("UnusedReturnValue") + public Nourishment getNourishment() { + return giant.getNourishment(); + } + + public void setNourishment(Nourishment nourishment) { + this.giant.setNourishment(nourishment); + } + + public void updateView() { + this.view.displayGiant(giant); + } +} +``` + ## Class diagram 

train

val

iluwatar

train

iluwatar/java-design-patterns/2297_2317

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2297

iluwatar/java-design-patterns/2317

e6f5b691df3033ad3a73c14f6ad9671efa49bb03

c4307db0a60c7b4612397ab1e1b911e0a78ccf13

Security vulnerability in H2 database

The currently used H2 database version 1.4.190 has multiple security vulnerabilities. To mention a few: 1. - H2 Console before 2.1.210 allows remote attackers to execute arbitrary code via a jdbc:h2:mem JDBC URL containing the IGNORE_UNKNOWN_SETTINGS=TRUE;FORBID_CREATION=FALSE;INIT=RUNSCRIPT substring, a different vulnerability than https://github.com/advisories/GHSA-h376-j262-vhq6 2. - H2 Console in versions since 1.1.100 (2008-10-14) to 2.0.204 (2021-12-21) inclusive allows loading of custom classes from remote servers through JNDI. 3. - The package com.h2database:h2 from 0 and before 2.0.202 are vulnerable to XML External Entity (XXE) Injection via the org.h2.jdbc.JdbcSQLXML class object, when it receives parsed string data from org.h2.jdbc.JdbcResultSet.getSQLXML() method. If it executes the getSource() method when the parameter is DOMSource.class it will trigger the vulnerability. Acceptance criteria - H2 database has been upgraded to the latest version

diff --git a/domain-model/src/main/java/com/iluwatar/domainmodel/App.java b/domain-model/src/main/java/com/iluwatar/domainmodel/App.java index 80058fb89a7a..681e7c4fc72a 100644 --- a/domain-model/src/main/java/com/iluwatar/domainmodel/App.java +++ b/domain-model/src/main/java/com/iluwatar/domainmodel/App.java @@ -60,8 +60,8 @@ public class App { + "customer_name varchar references CUSTOMERS(name));"; public static final String DELETE_SCHEMA_SQL = - "DROP TABLE CUSTOMERS IF EXISTS;" - + "DROP TABLE PURCHASES IF EXISTS;" + "DROP TABLE PURCHASES IF EXISTS;" + + "DROP TABLE CUSTOMERS IF EXISTS;" + "DROP TABLE PRODUCTS IF EXISTS;"; /** diff --git a/metadata-mapping/README.md b/metadata-mapping/README.md index 4cea6b10f84f..612188cbe267 100644 --- a/metadata-mapping/README.md +++ b/metadata-mapping/README.md @@ -26,14 +26,14 @@ Wikipedia says **Programmatic Example** -We give an example about visiting the information of `USER` table in `h2` database. Firstly, we create `USER` table with `h2`: +We give an example about visiting the information of `user_account` table in `h2` database. Firstly, we create `user_account` table with `h2`: ```java @Slf4j public class DatabaseUtil { private static final String DB_URL = "jdbc:h2:mem:metamapping"; - private static final String CREATE_SCHEMA_SQL = "DROP TABLE IF EXISTS `user`;" - + "CREATE TABLE `user` (\n" + private static final String CREATE_SCHEMA_SQL = "DROP TABLE IF EXISTS `user_account`;" + + "CREATE TABLE `user_account` (\n" + " `id` int(11) NOT NULL AUTO_INCREMENT,\n" + " `username` varchar(255) NOT NULL,\n" + " `password` varchar(255) NOT NULL,\n" @@ -88,7 +88,7 @@ Then we write a `xml` file to show the mapping between the table and the object: "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping> - <class name="com.iluwatar.metamapping.model.User" table="user"> + <class name="com.iluwatar.metamapping.model.User" table="user_account"> <id name="id" type="java.lang.Integer" column="id"> <generator class="native"/> </id> diff --git a/metadata-mapping/src/main/java/com/iluwatar/metamapping/utils/DatabaseUtil.java b/metadata-mapping/src/main/java/com/iluwatar/metamapping/utils/DatabaseUtil.java index 55f06ed9a794..048f470aebf4 100644 --- a/metadata-mapping/src/main/java/com/iluwatar/metamapping/utils/DatabaseUtil.java +++ b/metadata-mapping/src/main/java/com/iluwatar/metamapping/utils/DatabaseUtil.java @@ -34,8 +34,8 @@ @Slf4j public class DatabaseUtil { private static final String DB_URL = "jdbc:h2:mem:metamapping"; - private static final String CREATE_SCHEMA_SQL = "DROP TABLE IF EXISTS `user`;" - + "CREATE TABLE `user` (\n" + private static final String CREATE_SCHEMA_SQL = "DROP TABLE IF EXISTS `user_account`;" + + "CREATE TABLE `user_account` (\n" + " `id` int(11) NOT NULL AUTO_INCREMENT,\n" + " `username` varchar(255) NOT NULL,\n" + " `password` varchar(255) NOT NULL,\n" diff --git a/metadata-mapping/src/main/resources/com/iluwatar/metamapping/model/User.hbm.xml b/metadata-mapping/src/main/resources/com/iluwatar/metamapping/model/User.hbm.xml index cd63c552d65d..38862c67a3f4 100644 --- a/metadata-mapping/src/main/resources/com/iluwatar/metamapping/model/User.hbm.xml +++ b/metadata-mapping/src/main/resources/com/iluwatar/metamapping/model/User.hbm.xml @@ -4,7 +4,7 @@ "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping> - <class name="com.iluwatar.metamapping.model.User" table="user"> + <class name="com.iluwatar.metamapping.model.User" table="user_account"> <id name="id" type="java.lang.Integer" column="id"> <generator class="native"/> </id> diff --git a/pom.xml b/pom.xml index fd1193bc15aa..ed94116b65cb 100644 --- a/pom.xml +++ b/pom.xml @@ -38,7 +38,6 @@ <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <sonar-maven-plugin.version>3.8.0.2131</sonar-maven-plugin.version> <spring-boot.version>2.7.5</spring-boot.version> - <h2.version>1.4.190</h2.version> <jacoco.version>0.8.8</jacoco.version> <commons-dbcp.version>1.4</commons-dbcp.version> <camel.version>2.25.1</camel.version> @@ -246,11 +245,6 @@ <type>pom</type> <scope>import</scope> </dependency> - <dependency> - <groupId>com.h2database</groupId> - <artifactId>h2</artifactId> - <version>${h2.version}</version> - </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> diff --git a/transaction-script/src/main/java/com/iluwatar/transactionscript/RoomSchemaSql.java b/transaction-script/src/main/java/com/iluwatar/transactionscript/RoomSchemaSql.java index acb96930ebf8..29cad58620ef 100644 --- a/transaction-script/src/main/java/com/iluwatar/transactionscript/RoomSchemaSql.java +++ b/transaction-script/src/main/java/com/iluwatar/transactionscript/RoomSchemaSql.java @@ -30,7 +30,7 @@ public final class RoomSchemaSql { public static final String CREATE_SCHEMA_SQL = - "CREATE TABLE ROOMS (ID NUMBER, ROOM_TYPE VARCHAR(100), PRICE INT(100), BOOKED VARCHAR(100))"; + "CREATE TABLE ROOMS (ID NUMBER, ROOM_TYPE VARCHAR(100), PRICE INT, BOOKED VARCHAR(100))"; public static final String DELETE_SCHEMA_SQL = "DROP TABLE ROOMS IF EXISTS"; private RoomSchemaSql() {

test

val

iluwatar

train

iluwatar/java-design-patterns/2326_2327

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2326

iluwatar/java-design-patterns/2327

dd456d4440406b920492485549e79fbc324a9382

a05cf33643dffdfbd624186dc98ab7aee4327c87

Minor enchancements to flyweight

Minor enhancements to flyweight: - AlchemistShopTest : line 59: use a Set<>(potions).size() than streaming - PotionFactory - small refactoring to reduce code duplication by adding the potion after each siwtch case.

diff --git a/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java b/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java index 91b75f548655..d01c5735d19e 100644 --- a/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java +++ b/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java @@ -48,7 +48,7 @@ public class UserGroup { */ public static void addUserToFreeGroup(final User user) throws IllegalArgumentException { if (paidGroup.contains(user)) { - throw new IllegalArgumentException("User all ready member of paid group."); + throw new IllegalArgumentException("User already member of paid group."); } else { if (!freeGroup.contains(user)) { freeGroup.add(user); @@ -65,7 +65,7 @@ public static void addUserToFreeGroup(final User user) throws IllegalArgumentExc */ public static void addUserToPaidGroup(final User user) throws IllegalArgumentException { if (freeGroup.contains(user)) { - throw new IllegalArgumentException("User all ready member of free group."); + throw new IllegalArgumentException("User already member of free group."); } else { if (!paidGroup.contains(user)) { paidGroup.add(user); diff --git a/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java b/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java index a05d99798604..814131732d62 100644 --- a/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java +++ b/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java @@ -46,27 +46,25 @@ Potion createPotion(PotionType type) { switch (type) { case HEALING: potion = new HealingPotion(); - potions.put(type, potion); break; case HOLY_WATER: potion = new HolyWaterPotion(); - potions.put(type, potion); break; case INVISIBILITY: potion = new InvisibilityPotion(); - potions.put(type, potion); break; case POISON: potion = new PoisonPotion(); - potions.put(type, potion); break; case STRENGTH: potion = new StrengthPotion(); - potions.put(type, potion); break; default: break; } + if (potion != null) { + potions.put(type, potion); + } } return potion; }

diff --git a/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java b/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java index 0448554384d3..79a70611ea95 100644 --- a/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java +++ b/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java @@ -28,6 +28,7 @@ import static org.junit.jupiter.api.Assertions.assertNotNull; import java.util.ArrayList; +import java.util.HashSet; import org.junit.jupiter.api.Test; /** @@ -55,8 +56,6 @@ void testShop() { // There are 13 potion instances, but only 5 unique instance types assertEquals(13, allPotions.size()); - assertEquals(5, allPotions.stream().map(System::identityHashCode).distinct().count()); - + assertEquals(5, new HashSet<>(allPotions).size()); } - }

train

val

StefanelStan

train

iluwatar/java-design-patterns/2325_2327

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2325

iluwatar/java-design-patterns/2327

dd456d4440406b920492485549e79fbc324a9382

a05cf33643dffdfbd624186dc98ab7aee4327c87

Feature Toggle mispelled comments

A small typo error: all ready (incorrect) instead of already

diff --git a/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java b/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java index 91b75f548655..d01c5735d19e 100644 --- a/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java +++ b/feature-toggle/src/main/java/com/iluwatar/featuretoggle/user/UserGroup.java @@ -48,7 +48,7 @@ public class UserGroup { */ public static void addUserToFreeGroup(final User user) throws IllegalArgumentException { if (paidGroup.contains(user)) { - throw new IllegalArgumentException("User all ready member of paid group."); + throw new IllegalArgumentException("User already member of paid group."); } else { if (!freeGroup.contains(user)) { freeGroup.add(user); @@ -65,7 +65,7 @@ public static void addUserToFreeGroup(final User user) throws IllegalArgumentExc */ public static void addUserToPaidGroup(final User user) throws IllegalArgumentException { if (freeGroup.contains(user)) { - throw new IllegalArgumentException("User all ready member of free group."); + throw new IllegalArgumentException("User already member of free group."); } else { if (!paidGroup.contains(user)) { paidGroup.add(user); diff --git a/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java b/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java index a05d99798604..814131732d62 100644 --- a/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java +++ b/flyweight/src/main/java/com/iluwatar/flyweight/PotionFactory.java @@ -46,27 +46,25 @@ Potion createPotion(PotionType type) { switch (type) { case HEALING: potion = new HealingPotion(); - potions.put(type, potion); break; case HOLY_WATER: potion = new HolyWaterPotion(); - potions.put(type, potion); break; case INVISIBILITY: potion = new InvisibilityPotion(); - potions.put(type, potion); break; case POISON: potion = new PoisonPotion(); - potions.put(type, potion); break; case STRENGTH: potion = new StrengthPotion(); - potions.put(type, potion); break; default: break; } + if (potion != null) { + potions.put(type, potion); + } } return potion; }

diff --git a/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java b/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java index 0448554384d3..79a70611ea95 100644 --- a/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java +++ b/flyweight/src/test/java/com/iluwatar/flyweight/AlchemistShopTest.java @@ -28,6 +28,7 @@ import static org.junit.jupiter.api.Assertions.assertNotNull; import java.util.ArrayList; +import java.util.HashSet; import org.junit.jupiter.api.Test; /** @@ -55,8 +56,6 @@ void testShop() { // There are 13 potion instances, but only 5 unique instance types assertEquals(13, allPotions.size()); - assertEquals(5, allPotions.stream().map(System::identityHashCode).distinct().count()); - + assertEquals(5, new HashSet<>(allPotions).size()); } - }

train

val

StefanelStan

train

iluwatar/java-design-patterns/2035_2331

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2035

iluwatar/java-design-patterns/2331

10fb952d85e93386a5b79e3b898fbd7361d5de4d

37bfecce30969c25a519d939eafcbff8023f60a7

Build with JDK 17

This task is part of the transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. Here we address the issues that come up when building the project with JDK 17 using language level Java 11. Acceptance criteria - Build the project with JDK 17 while keeping the maven-compiler-plugin language level at 11 - Fix the errors that come up during the build

diff --git a/.circleci/config.yml b/.circleci/config.yml index dad7997a8699..714bd108889a 100644 --- a/.circleci/config.yml +++ b/.circleci/config.yml @@ -26,14 +26,14 @@ version: 2 jobs: sonar-pr: docker: - - image: cimg/openjdk:11.0-node + - image: cimg/openjdk:17.0-node steps: - checkout - restore_cache: key: jdp-sonar-pr-{{ checksum "pom.xml" }} - run: | sudo apt-get update - sudo apt-get install -y openjdk-11-jdk xvfb + sudo apt-get install -y openjdk-17-jdk xvfb if [ -n "${CIRCLE_PR_NUMBER}" ]; then MAVEN_OPTS="-Xmx3000m" xvfb-run ./mvnw -B clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \ -Dsonar.pullrequest.key=${CIRCLE_PR_NUMBER} \ diff --git a/.github/workflows/maven-ci.yml b/.github/workflows/maven-ci.yml index 1f490cf31be8..f9d8b063dd9c 100644 --- a/.github/workflows/maven-ci.yml +++ b/.github/workflows/maven-ci.yml @@ -39,7 +39,7 @@ jobs: # This Workflow Job will build this project and run Sonar analysis using JDK 11.0.3 build-and-analyze: - name: Build and Run Sonar analysis on JDK 11.0.3 + name: Build and Run Sonar analysis on JDK 17 runs-on: ubuntu-20.04 steps: @@ -49,11 +49,11 @@ jobs: # Disabling shallow clone for improving relevancy of SonarQube reporting fetch-depth: 0 - - name: Set up JDK 11.0.3 + - name: Set up JDK 17 uses: actions/setup-java@v3 with: - java-version: 11.0.3 - distribution: 'zulu' + java-version: '17' + distribution: 'temurin' cache: 'maven' # Cache Sonar packages which as used to run anaylysis and collect metrics @@ -79,18 +79,18 @@ jobs: # This Workflow Job is going to build the project on the latest stable JDK 11 build: - name: Build and Test on JDK 11 + name: Build and Test on JDK 17 runs-on: ubuntu-20.04 steps: - name: Checkout Code uses: actions/checkout@v3 - - name: Set up JDK 11 (Latest) + - name: Set up JDK 17 uses: actions/setup-java@v3 with: - java-version: 11 - distribution: 'zulu' + java-version: '17' + distribution: 'temurin' cache: 'maven' # Some tests need screen access diff --git a/.github/workflows/maven-pr-builder.yml b/.github/workflows/maven-pr-builder.yml index 66d39d40df7a..62664d614ea0 100644 --- a/.github/workflows/maven-pr-builder.yml +++ b/.github/workflows/maven-pr-builder.yml @@ -34,21 +34,18 @@ on: jobs: build: - name: Build JDP + name: Build on JDK 17 runs-on: ubuntu-20.04 - strategy: - matrix: - java-version: [ 11.0.3, 11 ] steps: - name: Checkout Code uses: actions/checkout@v3 - - name: Set up JDK ${{ matrix.java-version }} + - name: Set up JDK 17 uses: actions/setup-java@v3 with: - java-version: ${{ matrix.java-version }} - distribution: 'zulu' + java-version: '17' + distribution: 'temurin' cache: 'maven' # Some tests need screen access

val

val

iluwatar

train

iluwatar/java-design-patterns/2036_2331

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2036

iluwatar/java-design-patterns/2331

10fb952d85e93386a5b79e3b898fbd7361d5de4d

37bfecce30969c25a519d939eafcbff8023f60a7

Run with Java 17

This is part of the transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. In this issue, we build the project using JDK 11 and try to run it with Java 17 runtime. Acceptance criteria - The project is built with JDK 11 - The pattern examples are executed with Java 17 runtime e.g. `java -jar proxy.jar` - The errors that come up in the testing are fixed

diff --git a/.circleci/config.yml b/.circleci/config.yml index dad7997a8699..714bd108889a 100644 --- a/.circleci/config.yml +++ b/.circleci/config.yml @@ -26,14 +26,14 @@ version: 2 jobs: sonar-pr: docker: - - image: cimg/openjdk:11.0-node + - image: cimg/openjdk:17.0-node steps: - checkout - restore_cache: key: jdp-sonar-pr-{{ checksum "pom.xml" }} - run: | sudo apt-get update - sudo apt-get install -y openjdk-11-jdk xvfb + sudo apt-get install -y openjdk-17-jdk xvfb if [ -n "${CIRCLE_PR_NUMBER}" ]; then MAVEN_OPTS="-Xmx3000m" xvfb-run ./mvnw -B clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \ -Dsonar.pullrequest.key=${CIRCLE_PR_NUMBER} \ diff --git a/.github/workflows/maven-ci.yml b/.github/workflows/maven-ci.yml index 1f490cf31be8..f9d8b063dd9c 100644 --- a/.github/workflows/maven-ci.yml +++ b/.github/workflows/maven-ci.yml @@ -39,7 +39,7 @@ jobs: # This Workflow Job will build this project and run Sonar analysis using JDK 11.0.3 build-and-analyze: - name: Build and Run Sonar analysis on JDK 11.0.3 + name: Build and Run Sonar analysis on JDK 17 runs-on: ubuntu-20.04 steps: @@ -49,11 +49,11 @@ jobs: # Disabling shallow clone for improving relevancy of SonarQube reporting fetch-depth: 0 - - name: Set up JDK 11.0.3 + - name: Set up JDK 17 uses: actions/setup-java@v3 with: - java-version: 11.0.3 - distribution: 'zulu' + java-version: '17' + distribution: 'temurin' cache: 'maven' # Cache Sonar packages which as used to run anaylysis and collect metrics @@ -79,18 +79,18 @@ jobs: # This Workflow Job is going to build the project on the latest stable JDK 11 build: - name: Build and Test on JDK 11 + name: Build and Test on JDK 17 runs-on: ubuntu-20.04 steps: - name: Checkout Code uses: actions/checkout@v3 - - name: Set up JDK 11 (Latest) + - name: Set up JDK 17 uses: actions/setup-java@v3 with: - java-version: 11 - distribution: 'zulu' + java-version: '17' + distribution: 'temurin' cache: 'maven' # Some tests need screen access diff --git a/.github/workflows/maven-pr-builder.yml b/.github/workflows/maven-pr-builder.yml index 66d39d40df7a..62664d614ea0 100644 --- a/.github/workflows/maven-pr-builder.yml +++ b/.github/workflows/maven-pr-builder.yml @@ -34,21 +34,18 @@ on: jobs: build: - name: Build JDP + name: Build on JDK 17 runs-on: ubuntu-20.04 - strategy: - matrix: - java-version: [ 11.0.3, 11 ] steps: - name: Checkout Code uses: actions/checkout@v3 - - name: Set up JDK ${{ matrix.java-version }} + - name: Set up JDK 17 uses: actions/setup-java@v3 with: - java-version: ${{ matrix.java-version }} - distribution: 'zulu' + java-version: '17' + distribution: 'temurin' cache: 'maven' # Some tests need screen access

val

val

iluwatar

train

iluwatar/java-design-patterns/2329_2332

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2329

iluwatar/java-design-patterns/2332

df735cb956a9a3c6555ded781e714fcbe24f24db

40fb6dda74f742298468f8952ba26ad774d973bf

Fix pattern categories

Some patterns have a small defect in the yaml frontmatter (README.md). Categories key should be renamed to category so that everything shows up correctly on the website. Acceptance criteria - The pattern yaml frontmatters have been checked to conform with https://github.com/iluwatar/java-design-patterns/wiki/01.-How-to-contribute

diff --git a/identity-map/README.md b/identity-map/README.md index a5bb4d38695a..6594f54eda9e 100644 --- a/identity-map/README.md +++ b/identity-map/README.md @@ -1,6 +1,6 @@ --- title: Identity Map -categories: Behavioral +category: Behavioral language: en tags: - Performance diff --git a/intercepting-filter/README.md b/intercepting-filter/README.md index f5aef5d03032..aef71f4f5a76 100644 --- a/intercepting-filter/README.md +++ b/intercepting-filter/README.md @@ -1,6 +1,6 @@ --- title: Intercepting Filter -categories: Behavioral +category: Behavioral language: en tags: - Decoupling diff --git a/interpreter/README.md b/interpreter/README.md index 61bf7501abbc..99d3c30e50ed 100644 --- a/interpreter/README.md +++ b/interpreter/README.md @@ -1,6 +1,6 @@ --- title: Interpreter -categories: Behavioral +category: Behavioral language: en tags: - Gang of Four diff --git a/iterator/README.md b/iterator/README.md index 3f36d0070167..b49151eab125 100644 --- a/iterator/README.md +++ b/iterator/README.md @@ -1,6 +1,6 @@ --- title: Iterator -categories: Behavioral +category: Behavioral language: en tags: - Gang of Four

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iluwatar

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iluwatar/java-design-patterns/2335_2338

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2335

iluwatar/java-design-patterns/2338

ab81f7e3d128c28ffbf5fa75b60da7845c4d371b

8596d38ebaecb99654f3660714b01935f8da4a91

Translate the aggregator-microservices readme to Spanish

Hi all! Following [01.-How to contribute document](https://github.com/iluwatar/java-design-patterns/wiki/01.-How-to-contribute) I create this issue because I want to contribute to actually open issue #2277 translating [aggregator-microservices/README.md](https://github.com/iluwatar/java-design-patterns/blob/master/aggregator-microservices/README.md) I will save it in a new repository fork from my account in [localization/es](https://github.com/iluwatar/java-design-patterns/tree/master/localization/es) ./aggregator-microservices new subfolder and will make a new Pull Request for be merged soon.

diff --git a/localization/es/aggregator-microservices/README.md b/localization/es/aggregator-microservices/README.md new file mode 100644 index 000000000000..2c1c6aab8ce0 --- /dev/null +++ b/localization/es/aggregator-microservices/README.md @@ -0,0 +1,107 @@ +--- +title: Aggregator Microservices +category: Architectural +language: es +tag: +- Cloud distributed +- Decoupling +- Microservices +--- + +## Intención + +El usuario realiza una sola llamada al servicio del agregador y, a continuación, el agregador llama a cada microservicio relevante. + +## Explicación + +ejemplo del mundo real + +> Nuestro mercado web necesita información sobre los productos y su inventario actual. Hace una llamada a un agregador +> servicio que a su vez llama al microservicio de información del producto y al microservicio de inventario del producto que devuelve la +> información combinada. + +En palabras sencillas + +> Aggregator Microservice recopila datos de varios microservicios y devuelve un agregado para su procesamiento. + +StackOverflow dice + +> Aggregator Microservice invoca múltiples servicios para lograr la funcionalidad requerida por la aplicación. + +**Ejemplo programático** + +Empecemos por el modelo de datos. Aquí está nuestro `Product`. + +```java +public class Product { + private String title; + private int productInventories; + // getters and setters -> + ... +} +``` + +A continuación, podemos presentar nuestro microservicio `Aggregator` (Agregador de microservicios). Contiene el `ProductInformationClient` (Información del producto del cliente) y el +`ProductInventoryClient` (Inventario del producto del cliente) de los clientes para llamar a los respectivos microservicios. + +```java +@RestController +public class Aggregator { + + @Resource + private ProductInformationClient informationClient; + + @Resource + private ProductInventoryClient inventoryClient; + + @RequestMapping(path = "/product", method = RequestMethod.GET) + public Product getProduct() { + + var product = new Product(); + var productTitle = informationClient.getProductTitle(); + var productInventory = inventoryClient.getProductInventories(); + + //Fallback to error message + product.setTitle(requireNonNullElse(productTitle, "Error: Fetching Product Title Failed")); + + //Fallback to default error inventory + product.setProductInventories(requireNonNullElse(productInventory, -1)); + + return product; + } +} +``` + +Esta es la esencia de la implementación de microservicios de información. El microservicio de inventario es similar, simplemente regresa +recuentos de inventario. + +```java +@RestController +public class InformationController { + @RequestMapping(value = "/information", method = RequestMethod.GET) + public String getProductTitle() { + return "The Product Title."; + } +} +``` + +Ahora llamando a nuestra REST API `Aggregator` devuelve la información del producto. + +```bash +curl http://localhost:50004/product +{"title":"The Product Title.","productInventories":5} +``` + +## Diagrama de clase + + + +## Aplicabilidad + +Utilice el patrón Agregador de microservicios (Aggregator Microservices) cuando necesite una API unificada para varios microservicios, independientemente del dispositivo cliente. + +## Créditos + +* [Patrones de diseño de microservicios] (http://web.archive.org/web/20190705163602/http://blog.arungupta.me/microservice-design-patterns/) +* [Patrones de microservicios: Con ejemplos en Java](https://www.amazon.com/gp/product/1617294543/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=1617294543&linkId=8b4e570267bc5fb8b8189917b461dc60) +* [Patrones de arquitectura: Descubra patrones esenciales en el ámbito más indispensable de la arquitectura empresarial](https://www.amazon.com/gp/product/B077T7V8RC/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=B077T7V8RC&linkId=c34d204bfe1b277914b420189f09c1a4)

train

val

KarmaTashiCat

train

iluwatar/java-design-patterns/2037_2357

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2037

iluwatar/java-design-patterns/2357

2d309b89283e824f3e9e252b99f7537e975e3642

9181210f8144ff7730938aa2d343b8e8923ba856

Upgrade dependencies to support Java 17

This issue is a part of the transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. Here we upgrade the dependencies so that they support Java 17. Acceptance criteria - Project dependencies have been upgraded so that each of them supports Java 17

diff --git a/pom.xml b/pom.xml index ee3465ca3cfe..74e54db37856 100644 --- a/pom.xml +++ b/pom.xml @@ -41,7 +41,8 @@ <jacoco.version>0.8.8</jacoco.version> <commons-dbcp.version>1.4</commons-dbcp.version> <htmlunit.version>2.66.0</htmlunit.version> - <guice.version>4.0</guice.version> + <gson.version>2.10</gson.version> + <guice.version>5.1.0</guice.version> <system-lambda.version>1.1.0</system-lambda.version> <urm.version>2.0.0</urm.version> <maven-surefire-plugin.version>3.0.0-M5</maven-surefire-plugin.version> @@ -230,7 +231,7 @@ <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> - <version>2.10</version> + <version>${gson.version}</version> </dependency> <dependency> <groupId>com.google.inject</groupId> @@ -414,4 +415,4 @@ </plugin> </plugins> </build> -</project> \ No newline at end of file +</project>

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iluwatar

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iluwatar/java-design-patterns/2037_2358

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2037

iluwatar/java-design-patterns/2358

10fb952d85e93386a5b79e3b898fbd7361d5de4d

cececd4f6402a96ee1b830d5695fbb00580cc226

Upgrade dependencies to support Java 17

This issue is a part of the transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. Here we upgrade the dependencies so that they support Java 17. Acceptance criteria - Project dependencies have been upgraded so that each of them supports Java 17

diff --git a/event-sourcing/pom.xml b/event-sourcing/pom.xml index 047c1ea0d293..ae609d67e76b 100644 --- a/event-sourcing/pom.xml +++ b/event-sourcing/pom.xml @@ -39,11 +39,9 @@ <artifactId>junit-jupiter-engine</artifactId> <scope>test</scope> </dependency> - <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson --> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> - <version>2.8.9</version> </dependency> </dependencies> <build> diff --git a/pom.xml b/pom.xml index 95247640c84f..ad1bd20560de 100644 --- a/pom.xml +++ b/pom.xml @@ -254,6 +254,11 @@ <artifactId>htmlunit</artifactId> <version>${htmlunit.version}</version> </dependency> + <dependency> + <groupId>com.google.code.gson</groupId> + <artifactId>gson</artifactId> + <version>2.10</version> + </dependency> <dependency> <groupId>com.google.inject</groupId> <artifactId>guice</artifactId> diff --git a/typeobjectpattern/pom.xml b/typeobjectpattern/pom.xml index 00aedd506bc7..6fe65fee84a9 100644 --- a/typeobjectpattern/pom.xml +++ b/typeobjectpattern/pom.xml @@ -35,9 +35,8 @@ <artifactId>typeobjectpattern</artifactId> <dependencies> <dependency> - <groupId>com.googlecode.json-simple</groupId> - <artifactId>json-simple</artifactId> - <version>1.1.1</version> + <groupId>com.google.code.gson</groupId> + <artifactId>gson</artifactId> </dependency> <dependency> <groupId>org.junit.jupiter</groupId> diff --git a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/App.java b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/App.java index de2837b71885..d120baca0f2c 100644 --- a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/App.java +++ b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/App.java @@ -24,9 +24,7 @@ */ package com.iluwatar.typeobject; -import java.io.IOException; import lombok.extern.slf4j.Slf4j; -import org.json.simple.parser.ParseException; /** * <p>Type object pattern is the pattern we use when the OOP concept of creating a base class and @@ -54,7 +52,7 @@ public class App { * * @param args command line args */ - public static void main(String[] args) throws IOException, ParseException { + public static void main(String[] args) { var givenTime = 50; //50ms var toWin = 500; //points var pointsWon = 0; diff --git a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java index 7dd423af67a8..94f8ec6632b1 100644 --- a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java +++ b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java @@ -24,13 +24,12 @@ */ package com.iluwatar.typeobject; +import com.google.gson.JsonParseException; import com.iluwatar.typeobject.Candy.Type; -import java.io.IOException; import java.security.SecureRandom; import java.util.ArrayList; import java.util.List; -import org.json.simple.parser.ParseException; /** * The CellPool class allows the reuse of crushed cells instead of creation of new cells each time. @@ -80,7 +79,7 @@ void addNewCell(Cell c) { pointer++; } - Candy[] assignRandomCandytypes() throws IOException, ParseException { + Candy[] assignRandomCandytypes() throws JsonParseException { var jp = new JsonParser(); jp.parse(); var randomCode = new Candy[jp.candies.size() - 2]; //exclude generic types 'fruit' and 'candy' diff --git a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/JsonParser.java b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/JsonParser.java index b9db69eb716d..da0588aa2607 100644 --- a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/JsonParser.java +++ b/typeobjectpattern/src/main/java/com/iluwatar/typeobject/JsonParser.java @@ -24,17 +24,13 @@ */ package com.iluwatar.typeobject; +import com.google.gson.JsonArray; +import com.google.gson.JsonObject; +import com.google.gson.JsonParseException; import com.iluwatar.typeobject.Candy.Type; -import java.io.File; -import java.io.FileReader; -import java.io.IOException; -import java.util.Hashtable; -import java.util.List; -import org.json.simple.JSONArray; -import org.json.simple.JSONObject; -import org.json.simple.parser.JSONParser; -import org.json.simple.parser.ParseException; +import java.io.InputStreamReader; +import java.util.Hashtable; /** * The JsonParser class helps parse the json file candy.json to get all the different candies. @@ -47,23 +43,21 @@ public class JsonParser { this.candies = new Hashtable<>(); } - void parse() throws IOException, ParseException { - var parser = new JSONParser(); - var workingDirectory = new File("").getAbsolutePath(); - var filePath = List.of("src", "main", "java", "com", "iluwatar", "typeobject", "candy.json"); - var absolutePath = workingDirectory + File.separator + String.join(File.separator, filePath); - var jo = (JSONObject) parser.parse(new FileReader(absolutePath)); - var a = (JSONArray) jo.get("candies"); - for (var o : a) { - var candy = (JSONObject) o; - var name = (String) candy.get("name"); - var parentName = (String) candy.get("parent"); - var t = (String) candy.get("type"); + void parse() throws JsonParseException { + var is = this.getClass().getClassLoader().getResourceAsStream("candy.json"); + var reader = new InputStreamReader(is); + var json = (JsonObject) com.google.gson.JsonParser.parseReader(reader); + var array = (JsonArray) json.get("candies"); + for (var item : array) { + var candy = (JsonObject) item; + var name = candy.get("name").getAsString(); + var parentName = candy.get("parent").getAsString(); + var t = candy.get("type").getAsString(); var type = Type.CRUSHABLE_CANDY; if (t.equals("rewardFruit")) { type = Type.REWARD_FRUIT; } - var points = Integer.parseInt((String) candy.get("points")); + var points = candy.get("points").getAsInt(); var c = new Candy(name, parentName, type, points); this.candies.put(name, c); } diff --git a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/candy.json b/typeobjectpattern/src/main/resources/candy.json similarity index 82% rename from typeobjectpattern/src/main/java/com/iluwatar/typeobject/candy.json rename to typeobjectpattern/src/main/resources/candy.json index 74430c318d72..61c5fd4c3eb3 100644 --- a/typeobjectpattern/src/main/java/com/iluwatar/typeobject/candy.json +++ b/typeobjectpattern/src/main/resources/candy.json @@ -3,43 +3,43 @@ "name" : "fruit", "parent" : "null", "type" : "rewardFruit", - "points" : "20" + "points" : 20 }, { "name" : "candy", "parent" : "null", "type" : "crushableCandy", - "points" : "10" + "points" : 10 }, { "name" : "cherry", "parent" : "fruit", "type" : "rewardFruit", - "points" : "0" + "points" : 0 }, { "name" : "mango", "parent" : "fruit", "type" : "rewardFruit", - "points" : "0" + "points" : 0 }, { "name" : "purple popsicle", "parent" : "candy", "type" : "crushableCandy", - "points" : "0" + "points" : 0 }, { "name" : "green jellybean", "parent" : "candy", "type" : "crushableCandy", - "points" : "0" + "points" : 0 }, { "name" : "orange gum", "parent" : "candy", "type" : "crushableCandy", - "points" : "0" + "points" : 0 } ] }

train

val

iluwatar

train

iluwatar/java-design-patterns/2037_2359

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2037

iluwatar/java-design-patterns/2359

10fb952d85e93386a5b79e3b898fbd7361d5de4d

9600a69b1e20419524c1661eea5cc21965a9c3c5

Upgrade dependencies to support Java 17

This issue is a part of the transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. Here we upgrade the dependencies so that they support Java 17. Acceptance criteria - Project dependencies have been upgraded so that each of them supports Java 17

diff --git a/acyclic-visitor/pom.xml b/acyclic-visitor/pom.xml index 34f16caa06ef..52604048e127 100644 --- a/acyclic-visitor/pom.xml +++ b/acyclic-visitor/pom.xml @@ -33,19 +33,7 @@ <version>1.26.0-SNAPSHOT</version> </parent> <artifactId>acyclic-visitor</artifactId> - <properties> - <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> - <maven.compiler.source>1.8</maven.compiler.source> - <maven.compiler.target>1.8</maven.compiler.target> - </properties> <dependencies> - <!-- https://mvnrepository.com/artifact/uk.org.lidalia/slf4j-test --> - <dependency> - <groupId>uk.org.lidalia</groupId> - <artifactId>slf4j-test</artifactId> - <version>1.2.0</version> - <scope>test</scope> - </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId>

diff --git a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java deleted file mode 100644 index c6aec8bef971..000000000000 --- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java +++ /dev/null @@ -1,80 +0,0 @@ -/* - * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). - * - * The MIT License - * Copyright © 2014-2022 Ilkka Seppälä - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ -package com.iluwatar.acyclicvisitor; - -import static org.junit.jupiter.api.Assertions.assertEquals; -import static uk.org.lidalia.slf4jext.Level.INFO; - -import com.google.common.collect.ImmutableList; -import org.junit.jupiter.api.AfterEach; -import org.junit.jupiter.api.BeforeEach; -import org.junit.jupiter.api.Test; -import uk.org.lidalia.slf4jtest.LoggingEvent; -import uk.org.lidalia.slf4jtest.TestLogger; -import uk.org.lidalia.slf4jtest.TestLoggerFactory; - -/** - * ConfigureForDosVisitor test class - */ -class ConfigureForDosVisitorTest { - - private final TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class); - - @Test - void testVisitForZoom() { - var conDos = new ConfigureForDosVisitor(); - var zoom = new Zoom(); - - conDos.visit(zoom); - - ImmutableList<LoggingEvent> loggingEvents = logger.getLoggingEvents(); - assertEquals(1, loggingEvents.size()); - for (LoggingEvent loggingEvent : loggingEvents) { - assertEquals(INFO, loggingEvent.getLevel()); - assertEquals(zoom + " used with Dos configurator.", loggingEvent.getMessage()); - } - } - - @Test - void testVisitForHayes() { - var conDos = new ConfigureForDosVisitor(); - var hayes = new Hayes(); - - conDos.visit(hayes); - - ImmutableList<LoggingEvent> loggingEvents = logger.getLoggingEvents(); - assertEquals(1, loggingEvents.size()); - for (LoggingEvent loggingEvent : loggingEvents) { - assertEquals(INFO, loggingEvent.getLevel()); - assertEquals(hayes + " used with Dos configurator.", loggingEvent.getMessage()); - } - } - - @BeforeEach - @AfterEach - void clearLoggers() { - TestLoggerFactory.clear(); - } -} diff --git a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java deleted file mode 100644 index 587b82911f81..000000000000 --- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java +++ /dev/null @@ -1,65 +0,0 @@ -/* - * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). - * - * The MIT License - * Copyright © 2014-2022 Ilkka Seppälä - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ -package com.iluwatar.acyclicvisitor; - -import com.google.common.collect.ImmutableList; -import org.junit.jupiter.api.AfterEach; -import org.junit.jupiter.api.BeforeEach; -import org.junit.jupiter.api.Test; -import uk.org.lidalia.slf4jtest.LoggingEvent; -import uk.org.lidalia.slf4jtest.TestLogger; -import uk.org.lidalia.slf4jtest.TestLoggerFactory; - -import static org.junit.jupiter.api.Assertions.assertEquals; -import static uk.org.lidalia.slf4jext.Level.INFO; - -/** - * ConfigureForUnixVisitor test class - */ -class ConfigureForUnixVisitorTest { - - private static final TestLogger LOGGER = TestLoggerFactory.getTestLogger(ConfigureForUnixVisitor.class); - - @BeforeEach - @AfterEach - void clearLoggers() { - TestLoggerFactory.clear(); - } - - @Test - void testVisitForZoom() { - var conUnix = new ConfigureForUnixVisitor(); - var zoom = new Zoom(); - - conUnix.visit(zoom); - - ImmutableList<LoggingEvent> loggingEvents = LOGGER.getLoggingEvents(); - assertEquals(1, loggingEvents.size()); - for (LoggingEvent loggingEvent : loggingEvents) { - assertEquals(INFO, loggingEvent.getLevel()); - assertEquals(zoom + " used with Unix configurator.", loggingEvent.getMessage()); - } - } -}

val

val

iluwatar

train

iluwatar/java-design-patterns/2369_2370

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2369

iluwatar/java-design-patterns/2370

37bfecce30969c25a519d939eafcbff8023f60a7

7a3d61776971236688b73bd59d5c5609a4dffd37

Reduce build logging

Currrently, the build with tests enabled produces a zipped log file of about 65MB. This is a bit too large to analyze effectively. Let's try to reduce the logging a bit while keeping the most important parts. Acceptance criteria - Build and tests produce more compact logs

diff --git a/monitor/src/main/java/com/iluwatar/monitor/Bank.java b/monitor/src/main/java/com/iluwatar/monitor/Bank.java index 6ff65f28cb9a..3f19e0f593a7 100644 --- a/monitor/src/main/java/com/iluwatar/monitor/Bank.java +++ b/monitor/src/main/java/com/iluwatar/monitor/Bank.java @@ -78,12 +78,14 @@ public synchronized void transfer(int accountA, int accountB, int amount) { if (accounts[accountA] >= amount) { accounts[accountB] += amount; accounts[accountA] -= amount; - LOGGER.info( - "Transferred from account: {} to account: {} , amount: {} , balance: {}", - accountA, - accountB, - amount, - getBalance()); + if (LOGGER.isDebugEnabled()) { + LOGGER.debug( + "Transferred from account: {} to account: {} , amount: {} , balance: {}", + accountA, + accountB, + amount, + getBalance()); + } } } diff --git a/monitor/src/main/java/com/iluwatar/monitor/Main.java b/monitor/src/main/java/com/iluwatar/monitor/Main.java index 8b2e8ab47997..923c720d8ef1 100644 --- a/monitor/src/main/java/com/iluwatar/monitor/Main.java +++ b/monitor/src/main/java/com/iluwatar/monitor/Main.java @@ -25,7 +25,7 @@ package com.iluwatar.monitor; import java.security.SecureRandom; -import java.util.concurrent.ExecutorService; +import java.util.concurrent.CountDownLatch; import java.util.concurrent.Executors; import lombok.extern.slf4j.Slf4j; @@ -40,20 +40,26 @@ @Slf4j public class Main { + private static final int NUMBER_OF_THREADS = 5; + /** * Runner to perform a bunch of transfers and handle exception. * - * @param bank bank object + * @param bank bank object + * @param latch signal finished execution */ - public static void runner(Bank bank) { + public static void runner(Bank bank, CountDownLatch latch) { try { SecureRandom random = new SecureRandom(); Thread.sleep(random.nextInt(1000)); + LOGGER.info("Start transferring..."); for (int i = 0; i < 1000000; i++) { bank.transfer(random.nextInt(4), random.nextInt(4), random.nextInt()); } + LOGGER.info("Finished transferring."); + latch.countDown(); } catch (InterruptedException e) { - LOGGER.info(e.getMessage()); + LOGGER.error(e.getMessage()); Thread.currentThread().interrupt(); } } @@ -63,12 +69,15 @@ public static void runner(Bank bank) { * * @param args command line args */ - public static void main(String[] args) { + public static void main(String[] args) throws InterruptedException { var bank = new Bank(4, 1000); - Runnable runnable = () -> runner(bank); - ExecutorService executorService = Executors.newFixedThreadPool(5); - for (int i = 0; i < 5; i++) { - executorService.execute(runnable); + var latch = new CountDownLatch(NUMBER_OF_THREADS); + var executorService = Executors.newFixedThreadPool(NUMBER_OF_THREADS); + + for (int i = 0; i < NUMBER_OF_THREADS; i++) { + executorService.execute(() -> runner(bank, latch)); } + + latch.await(); } } diff --git a/monitor/src/test/resources/logback.xml b/monitor/src/test/resources/logback.xml new file mode 100644 index 000000000000..ce9892722558 --- /dev/null +++ b/monitor/src/test/resources/logback.xml @@ -0,0 +1,35 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + The MIT License + Copyright © 2014-2022 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<configuration> + <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> + <encoder> + <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern> + </encoder> + </appender> + <root level="info"> + <appender-ref ref="STDOUT" /> + </root> +</configuration>

diff --git a/monitor/src/test/java/com/iluwatar/monitor/MainTest.java b/monitor/src/test/java/com/iluwatar/monitor/MainTest.java index 360a897fd6a6..4d1c217372d7 100644 --- a/monitor/src/test/java/com/iluwatar/monitor/MainTest.java +++ b/monitor/src/test/java/com/iluwatar/monitor/MainTest.java @@ -25,6 +25,7 @@ package com.iluwatar.monitor; import org.junit.jupiter.api.Test; +import java.util.concurrent.CountDownLatch; import static org.junit.jupiter.api.Assertions.*; /** Test if the application starts without throwing an exception. */ @@ -38,6 +39,9 @@ void shouldExecuteApplicationWithoutException() { @Test void RunnerExecuteWithoutException() { var bank = new Bank(4, 1000); - assertDoesNotThrow(() -> Main.runner(bank)); + var latch = new CountDownLatch(1); + + assertDoesNotThrow(() -> Main.runner(bank, latch)); + assertEquals(0, latch.getCount()); } }

train

val

iluwatar

train

iluwatar/java-design-patterns/1295_2384

iluwatar/java-design-patterns

iluwatar/java-design-patterns/1295

iluwatar/java-design-patterns/2384

7d2832f4124a1ccbe1ba67c003330ad78b188207

b2eb312b5e18179051f5dc12bddff27a1c6388fe

Embedded Value pattern

https://www.youtube.com/watch?v=6n5O5mCdnew

diff --git a/embedded-value/README.md b/embedded-value/README.md new file mode 100644 index 000000000000..dc924cb45a0f --- /dev/null +++ b/embedded-value/README.md @@ -0,0 +1,124 @@ +--- +title: Embedded Value +category: Structural +language: en +tag: + - Data Access + - Enterprise Application Pattern +--- + +## Also known as +Aggregate Mapping, Composer + +## Intent +Many small objects make sense in an OO system that don’t make sense as +tables in a database. An Embedded Value maps the values of an object to fields in the record of the object’s owner. + +## Explanation + +Real-world example + +> Examples include currency-aware money objects and date +ranges. Although the default thinking is to save an object as a table, no sane person would want a table of money values. +> Another example would be the online orders which have a shipping address like street, city, state. We map these values of Shipping address object to fields in record of Order object. + +In plain words + +> Embedded value pattern let's you map an object into several fields of another object’s table. + +**Programmatic Example** + +Consider online order's example where we have details of item ordered and shipping address. We have Shipping address embedded in Order object. But in database we map shipping address values in Order record instead of creating a separate table for Shipping address and using foreign key to reference the order object. + +First, we have POJOs `Order` and `ShippingAddress` + +```java +public class Order { + + private int id; + private String item; + private String orderedBy; + private ShippingAddress ShippingAddress; + + public Order(String item, String orderedBy, ShippingAddress ShippingAddress) { + this.item = item; + this.orderedBy = orderedBy; + this.ShippingAddress = ShippingAddress; + } +``` +```java +public class ShippingAddress { + + private String city; + private String state; + private String pincode; + + public ShippingAddress(String city, String state, String pincode) { + this.city = city; + this.state = state; + this.pincode = pincode; + } +} +``` +Now, we have to create only one table for Order along with fields for shipping address attributes. + +```Sql +CREATE TABLE Orders (Id INT AUTO_INCREMENT, item VARCHAR(50) NOT NULL, orderedBy VARCHAR(50) city VARCHAR(50), state VARCHAR(50), pincode CHAR(6) NOT NULL, PRIMARY KEY(Id)) +``` + +While performing the database queries and inserts, we box and unbox shipping address details. + +```java +final String INSERT_ORDER = "INSERT INTO Orders (item, orderedBy, city, state, pincode) VALUES (?, ?, ?, ?, ?)"; + +public boolean insertOrder(Order order) throws Exception { + var insertOrder = new PreparedStatement(INSERT_ORDER); + var address = order.getShippingAddress(); + conn.setAutoCommit(false); + insertIntoOrders.setString(1, order.getItem()); + insertIntoOrders.setString(2, order.getOrderedBy()); + insertIntoOrders.setString(3, address.getCity()); + insertIntoOrders.setString(4, address.getState()); + insertIntoOrders.setString(5, address.getPincode()); + + var affectedRows = insertIntoOrders.executeUpdate(); + if(affectedRows == 1){ + Logger.info("Inserted successfully"); + }else{ + Logger.info("Couldn't insert " + order); + } +} +``` + +## Class diagram + + +## Applicability + +Use the Embedded value pattern when + +* Many small objects make sense in an OO system that don’t make sense as tables in a database. +* The simplest cases for Embedded Value are the clear, simple Value Objects like money and date range. +* If you’re mapping to an existing schema, you can use this pattern when a table contains data that you want to split into more than one object in memory. This can occur when you want to factor out some behaviour in object model. +* In most cases you’ll only use Embedded Value on a reference object when the association between them is single valued at both ends (a one-to-one association). +* It can only be used for fairly simple dependents. A solitary dependent, or a few separated dependents, works well. + +## Tutorials + +* [Dzone](https://dzone.com/articles/practical-php-patterns/practical-php-patterns-3) +* [Ram N Java](https://ramj2ee.blogspot.com/2013/08/embedded-value-design-pattern.html) +* [Five's Weblog](https://powerdream5.wordpress.com/2007/10/09/embedded-value/) + +## Consequences + +* The great advantage of Embedded Value is that it allows SQL queries to be made against the values in the dependent object. +* The embedded value object has no persistence behaviour at all. +* While using this, you have to be careful that any change to the dependent marks the owner as dirty—which isn’t an issue with Value Objects that are replaced in the owner. +* Another issue is the loading and saving. If you only load the embedded object memory when you load the owner, that’s an argument for saving both in the same table. +* Another question is whether you’ll want to access the embedded objects' data separately through SQL. This can be important if you’re reporting through SQL and don’t have a separate database for reporting. + + +## Credits + +* [Fowler, Martin - Patterns of enterprise application architecture-Addison-Wesley](https://www.amazon.com/Patterns-Enterprise-Application-Architecture-Martin/dp/0321127420) +* [Ram N Java](https://ramj2ee.blogspot.com/2013/08/embedded-value-design-pattern.html) \ No newline at end of file diff --git a/embedded-value/etc/embedded-value.urm.puml b/embedded-value/etc/embedded-value.urm.puml new file mode 100644 index 000000000000..ed73802792a2 --- /dev/null +++ b/embedded-value/etc/embedded-value.urm.puml @@ -0,0 +1,79 @@ +@startuml +package com.iluwatar.embedded.value { + class App { + - LOGGER : Logger {static} + + App() + + main(args : String[]) {static} + } + class DataSource { + - LOGGER : Logger {static} + - conn : Connection + - createschema : Statement + - deleteschema : Statement + - getschema : Statement + - insertIntoOrders : PreparedStatement + - queryOrders : Statement + - queyOrderByID : PreparedStatement + - removeorder : PreparedStatement + + DataSource() + + createSchema() : boolean + + deleteSchema() : boolean + + getSchema() : String + + insertOrder(order : Order) : boolean + + queryOrder(id : int) : Order + + queryOrders() : Stream<Order> + + removeOrder(id : int) + } + ~interface DataSourceInterface { + + CREATE_SCHEMA : String {static} + + DELETE_SCHEMA : String {static} + + GET_SCHEMA : String {static} + + INSERT_ORDER : String {static} + + JDBC_URL : String {static} + + QUERY_ORDER : String {static} + + QUERY_ORDERS : String {static} + + REMOVE_ORDER : String {static} + + createSchema() : boolean {abstract} + + deleteSchema() : boolean {abstract} + + getSchema() : String {abstract} + + insertOrder(Order) : boolean {abstract} + + queryOrder(int) : Order {abstract} + + queryOrders() : Stream<Order> {abstract} + + removeOrder(int) {abstract} + } + class Order { + - id : int + - item : String + - orderedBy : String + - shippingAddress : ShippingAddress + + Order() + + Order(id : int, item : String, orderedBy : String, shippingAddress : ShippingAddress) + + Order(item : String, orderedBy : String, shippingAddress : ShippingAddress) + + getId() : int + + getItem() : String + + getOrderedBy() : String + + getShippingAddress() : ShippingAddress + + setId(id : int) + + setItem(item : String) + + setOrderedBy(orderedBy : String) + + setShippingAddress(shippingAddress : ShippingAddress) + + toString() : String + } + class ShippingAddress { + - city : String + - pincode : String + - state : String + + ShippingAddress() + + ShippingAddress(city : String, state : String, pincode : String) + + getCity() : String + + getPincode() : String + + getState() : String + + setCity(city : String) + + setPincode(pincode : String) + + setState(state : String) + + toString() : String + } +} +Order --> "-shippingAddress" ShippingAddress +DataSource ..|> DataSourceInterface +@enduml \ No newline at end of file diff --git a/embedded-value/pom.xml b/embedded-value/pom.xml new file mode 100644 index 000000000000..ccef450e4bfc --- /dev/null +++ b/embedded-value/pom.xml @@ -0,0 +1,66 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + + This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + + The MIT License + Copyright © 2014-2022 Ilkka Seppälä + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +--> +<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + <parent> + <groupId>com.iluwatar</groupId> + <artifactId>java-design-patterns</artifactId> + <version>1.26.0-SNAPSHOT</version> + </parent> + <artifactId>embedded-value</artifactId> + <dependencies> + <dependency> + <groupId>com.h2database</groupId> + <artifactId>h2</artifactId> + </dependency> + <dependency> + <groupId>org.junit.jupiter</groupId> + <artifactId>junit-jupiter-engine</artifactId> + <scope>test</scope> + </dependency> + </dependencies> + <build> + <plugins> + <plugin> + <groupId>org.apache.maven.plugins</groupId> + <artifactId>maven-assembly-plugin</artifactId> + <executions> + <execution> + <configuration> + <archive> + <manifest> + <mainClass>com.iluwatar.embedded.value.App</mainClass> + </manifest> + </archive> + </configuration> + </execution> + </executions> + </plugin> + </plugins> + </build> +</project> \ No newline at end of file diff --git a/embedded-value/src/main/java/com/iluwatar/embedded/value/App.java b/embedded-value/src/main/java/com/iluwatar/embedded/value/App.java new file mode 100644 index 000000000000..9e5011c5980e --- /dev/null +++ b/embedded-value/src/main/java/com/iluwatar/embedded/value/App.java @@ -0,0 +1,114 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.embedded.value; + +import java.util.stream.Collectors; + +import lombok.extern.slf4j.Slf4j; + +/* + * Many small objects make sense in an OO system that don’t make sense as + * tables in a database. Examples include currency-aware money objects (amount, currency) and date + * ranges. Although the default thinking is to save an object as a table, no sane + * person would want a table of money values. + * + * An Embedded Value maps the values of an object to fields in the record of + * the object’s owner. In this implementation we have an Order object with links to an + * ShippingAddress object. In the resulting table the fields in the ShippingAddress + * object map to fields in the Order table rather than make new records + * themselves. + */ + +@Slf4j +public class App { + + /** + * Program entry point. + * + * @param args command line args. + * @throws Exception if any error occurs. + * + */ + public static void main(String[] args) throws Exception { + final var dataSource = new DataSource(); + + // Orders to insert into database + final var order1 = new Order("JBL headphone", "Ram", + new ShippingAddress("Bangalore", "Karnataka", "560040")); + final var order2 = new Order("MacBook Pro", "Manjunath", + new ShippingAddress("Bangalore", "Karnataka", "581204")); + final var order3 = new Order("Carrie Soto is Back", "Shiva", + new ShippingAddress("Bangalore", "Karnataka", "560004")); + + /** + * Create table for orders - Orders(id, name, orderedBy, city, state, pincode). + * We can see that table is different from the Order object we have. + * We're mapping ShippingAddress into city, state, pincode colummns of the database and not creating a separate table. + */ + if (dataSource.createSchema()) { + LOGGER.info("TABLE CREATED"); + LOGGER.info("Table \"Orders\" schema:\n" + dataSource.getSchema()); + } else { + //If not able to create table, there's nothing we can do further. + LOGGER.error("Error creating table"); + System.exit(0); + } + + // Initially, database is empty + LOGGER.info("Orders Query: {}", dataSource.queryOrders().collect(Collectors.toList())); + + //Insert orders where shippingAddress is mapped to different columns of the same table + dataSource.insertOrder(order1); + dataSource.insertOrder(order2); + dataSource.insertOrder(order3); + + /** + * Query orders + * We'll create ShippingAddress object from city, state, pincode values from the table + * and add it to Order object + */ + LOGGER.info("Orders Query: {}", dataSource.queryOrders().collect(Collectors.toList()) + "\n"); + + //Query order by given id + LOGGER.info("Query Order with id=2: {}", dataSource.queryOrder(2)); + + /** + * Remove order by given id. + * Since we'd mapped address in the same table, deleting order will also take + * out the shipping address details + */ + LOGGER.info("Remove Order with id=1"); + dataSource.removeOrder(1); + LOGGER.info("\nOrders Query: {}", dataSource.queryOrders().collect(Collectors.toList()) + "\n"); + + //After successfull demonstration of the pattern, drop the table + if (dataSource.deleteSchema()) { + LOGGER.info("TABLE DROPPED"); + } else { + //If there's a potential error while dropping table + LOGGER.error("Error deleting table"); + } + } +} diff --git a/embedded-value/src/main/java/com/iluwatar/embedded/value/DataSource.java b/embedded-value/src/main/java/com/iluwatar/embedded/value/DataSource.java new file mode 100644 index 000000000000..e2ec2ed7c023 --- /dev/null +++ b/embedded-value/src/main/java/com/iluwatar/embedded/value/DataSource.java @@ -0,0 +1,217 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.embedded.value; + +import java.sql.Connection; +import java.sql.DriverManager; +import java.sql.PreparedStatement; +import java.sql.SQLException; +import java.sql.Statement; +import java.util.ArrayList; +import java.util.stream.Stream; + +import lombok.extern.slf4j.Slf4j; +/* + * Communicates with H2 database with the help of JDBC API + * + * Inherits the SQL queries and methods from @link AbstractDataSource class + */ + +@Slf4j +public class DataSource implements DataSourceInterface { + private Connection conn; + + /** + * Statements are objects which are used to execute queries which will not be + * repeated. + */ + private Statement getschema; + private Statement deleteschema; + private Statement queryOrders; + + /* + * PreparedStatements are used to execute queries which will be repeated. + */ + private PreparedStatement insertIntoOrders; + private PreparedStatement removeorder; + private PreparedStatement queyOrderByID; + + /** + * {@summary} + * Establish connection to database. + */ + public DataSource() { + try { + conn = DriverManager.getConnection(JDBC_URL); + LOGGER.info("Connected to H2 in-memory database: " + conn.getCatalog()); + } catch (SQLException e) { + LOGGER.error(e.getLocalizedMessage(), e.getCause()); + } + } + + @Override + public boolean createSchema() { + try (Statement createschema = conn.createStatement()) { + createschema.execute(CREATE_SCHEMA); + insertIntoOrders = conn.prepareStatement(INSERT_ORDER, PreparedStatement.RETURN_GENERATED_KEYS); + getschema = conn.createStatement(); + queryOrders = conn.createStatement(); + removeorder = conn.prepareStatement(REMOVE_ORDER); + queyOrderByID = conn.prepareStatement(QUERY_ORDER); + deleteschema = conn.createStatement(); + } catch (SQLException e) { + LOGGER.error(e.getLocalizedMessage(), e.getCause()); + return false; + } + return true; + } + + @Override + public String getSchema() { + try { + var resultSet = getschema.executeQuery(GET_SCHEMA); + var sb = new StringBuilder(); + while (resultSet.next()) { + sb.append("Col name: " + resultSet.getString(1) + ", Col type: " + resultSet.getString(2) + "\n"); + } + getschema.close(); + return sb.toString(); + } catch (Exception e) { + LOGGER.error("Error in retrieving schema: {}", e.getLocalizedMessage(), e.getCause()); + } + return "Schema unavailable"; + } + + @Override + public boolean insertOrder(Order order) { + try { + conn.setAutoCommit(false); + insertIntoOrders.setString(1, order.getItem()); + insertIntoOrders.setString(2, order.getOrderedBy()); + var address = order.getShippingAddress(); + insertIntoOrders.setString(3, address.getCity()); + insertIntoOrders.setString(4, address.getState()); + insertIntoOrders.setString(5, address.getPincode()); + var affectedRows = insertIntoOrders.executeUpdate(); + if (affectedRows == 1) { + var rs = insertIntoOrders.getGeneratedKeys(); + rs.last(); + var insertedAddress = new ShippingAddress(address.getCity(), address.getState(), address.getPincode()); + var insertedOrder = new Order(rs.getInt(1), order.getItem(), order.getOrderedBy(), + insertedAddress); + conn.commit(); + LOGGER.info("Inserted: {}", insertedOrder); + } else { + conn.rollback(); + } + } catch (Exception e) { + LOGGER.error(e.getLocalizedMessage()); + } finally { + try { + conn.setAutoCommit(true); + } catch (SQLException e) { + LOGGER.error(e.getLocalizedMessage()); + } + } + return true; + } + + @Override + public Stream<Order> queryOrders() { + var ordersList = new ArrayList<Order>(); + try (var rSet = queryOrders.executeQuery(QUERY_ORDERS)) { + while (rSet.next()) { + var order = new Order(rSet.getInt(1), rSet.getString(2), rSet.getString(3), + new ShippingAddress(rSet.getString(4), rSet.getString(5), + rSet.getString(6))); + ordersList.add(order); + } + rSet.close(); + } catch (SQLException e) { + LOGGER.error(e.getMessage(), e.getCause()); + } + return ordersList.stream(); + } + + /** + * {@summary} + * Query order by given id. + * @param id as the parameter + * @return Order objct + * @throws SQLException in case of unexpected events + */ + + @Override + public Order queryOrder(int id) throws SQLException { + Order order = null; + queyOrderByID.setInt(1, id); + try (var rSet = queyOrderByID.executeQuery()) { + queyOrderByID.setInt(1, id); + if (rSet.next()) { + var address = new ShippingAddress(rSet.getString(4), + rSet.getString(5), rSet.getString(6)); + order = new Order(rSet.getInt(1), rSet.getString(2), rSet.getString(3), address); + } + rSet.close(); + } catch (Exception e) { + LOGGER.error(e.getLocalizedMessage(), e.getCause()); + } + return order; + } + + @Override + public void removeOrder(int id) throws Exception { + try { + conn.setAutoCommit(false); + removeorder.setInt(1, id); + if (removeorder.executeUpdate() == 1) { + LOGGER.info("Order with id " + id + " successfully removed"); + } else { + LOGGER.info("Order with id " + id + " unavailable."); + } + } catch (Exception e) { + LOGGER.error(e.getLocalizedMessage(), e.getCause()); + conn.rollback(); + } finally { + conn.setAutoCommit(true); + } + } + + @Override + public boolean deleteSchema() throws Exception { + try { + deleteschema.execute(DELETE_SCHEMA); + queryOrders.close(); + queyOrderByID.close(); + deleteschema.close(); + insertIntoOrders.close(); + conn.close(); + return true; + } catch (Exception e) { + LOGGER.error(e.getLocalizedMessage(), e.getCause()); + } + return false; + } +} diff --git a/embedded-value/src/main/java/com/iluwatar/embedded/value/DataSourceInterface.java b/embedded-value/src/main/java/com/iluwatar/embedded/value/DataSourceInterface.java new file mode 100644 index 000000000000..deddf55b93ac --- /dev/null +++ b/embedded-value/src/main/java/com/iluwatar/embedded/value/DataSourceInterface.java @@ -0,0 +1,69 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.embedded.value; + +import java.sql.SQLException; +import java.util.stream.Stream; + +/* + * Abstract class which contains the required SQL queries and basic methods declaration. + * + * The main thing to consider is that the ShippingAddress object doesn't have it's own class + * but it's values are stored into the Orders table as city, state, pincode + * + */ +interface DataSourceInterface { + + final String JDBC_URL = "jdbc:h2:mem:Embedded-Value"; + + final String CREATE_SCHEMA = "CREATE TABLE Orders (Id INT AUTO_INCREMENT, item VARCHAR(50) NOT NULL, orderedBy VARCHAR(50)" + + ", city VARCHAR(50), state VARCHAR(50), pincode CHAR(6) NOT NULL, PRIMARY KEY(Id))"; + + final String GET_SCHEMA = "SHOW COLUMNS FROM Orders"; + + final String INSERT_ORDER = "INSERT INTO Orders (item, orderedBy, city, state, pincode) VALUES(?, ?, ?, ?, ?)"; + + final String QUERY_ORDERS = "SELECT * FROM Orders"; + + final String QUERY_ORDER = QUERY_ORDERS + " WHERE Id = ?"; + + final String REMOVE_ORDER = "DELETE FROM Orders WHERE Id = ?"; + + final String DELETE_SCHEMA = "DROP TABLE Orders"; + + boolean createSchema() throws SQLException; + + String getSchema() throws SQLException; + + boolean insertOrder(Order order) throws SQLException; + + Stream<Order> queryOrders() throws SQLException; + + Order queryOrder(int id) throws SQLException; + + void removeOrder(int id) throws Exception; + + boolean deleteSchema() throws Exception; +} diff --git a/embedded-value/src/main/java/com/iluwatar/embedded/value/Order.java b/embedded-value/src/main/java/com/iluwatar/embedded/value/Order.java new file mode 100644 index 000000000000..9c87a83f6ec0 --- /dev/null +++ b/embedded-value/src/main/java/com/iluwatar/embedded/value/Order.java @@ -0,0 +1,61 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.embedded.value; + +import lombok.Getter; +import lombok.Setter; +import lombok.ToString; +/* + * A POJO which represents the Order object. + */ +@ToString +@Setter +@Getter +public class Order { + + private int id; + private String item; + private String orderedBy; + private ShippingAddress shippingAddress; + + /** + * Constructor for Item object. + * @param item item name + * @param orderedBy item orderer + * @param shippingAddress shipping address details + */ + + public Order(String item, String orderedBy, ShippingAddress shippingAddress) { + this.item = item; + this.orderedBy = orderedBy; + this.shippingAddress = shippingAddress; + } + + public Order(int id, String item, String orderedBy, ShippingAddress shippingAddress) { + this(item, orderedBy, shippingAddress); + this.id = id; + } + +} diff --git a/embedded-value/src/main/java/com/iluwatar/embedded/value/ShippingAddress.java b/embedded-value/src/main/java/com/iluwatar/embedded/value/ShippingAddress.java new file mode 100644 index 000000000000..9b04519dd17e --- /dev/null +++ b/embedded-value/src/main/java/com/iluwatar/embedded/value/ShippingAddress.java @@ -0,0 +1,54 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.embedded.value; + +import lombok.Getter; +import lombok.ToString; + +/** + * Another POJO which wraps the Shipping details of order into Object. + */ +@ToString +@Getter +public class ShippingAddress { + + private String city; + private String state; + private String pincode; + + /** + * Constructor for Shipping Address object. + * @param city City name + * @param state State name + * @param pincode Pin code of the city + * + */ + public ShippingAddress(String city, String state, String pincode) { + this.city = city; + this.state = state; + this.pincode = pincode; + } +} + diff --git a/pom.xml b/pom.xml index 68714e28a007..3f491033a80a 100644 --- a/pom.xml +++ b/pom.xml @@ -198,6 +198,7 @@ <module>composite-view</module> <module>metadata-mapping</module> <module>service-to-worker</module> + <module>embedded-value</module> <module>currying</module> <module>serialized-entity</module> <module>identity-map</module>

diff --git a/embedded-value/src/test/java/com/iluwatar/embedded/value/AppTest.java b/embedded-value/src/test/java/com/iluwatar/embedded/value/AppTest.java new file mode 100644 index 000000000000..1e97bfabc36f --- /dev/null +++ b/embedded-value/src/test/java/com/iluwatar/embedded/value/AppTest.java @@ -0,0 +1,41 @@ +/* + * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). + * + * The MIT License + * Copyright © 2014-2022 Ilkka Seppälä + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +package com.iluwatar.embedded.value; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; + +import org.junit.jupiter.api.Test; + +/** + * Check whether the execution of the main method in {@link App} + * throws an exception. +*/ +public class AppTest { + + @Test + public void doesNotThrowException() { + assertDoesNotThrow(() -> App.main(new String[] {})); + } +}

val

val

iluwatar

train

iluwatar/java-design-patterns/2399_2400

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2399

iluwatar/java-design-patterns/2400

9a92930dfae8945c6a3ba61e73ee147296e825b3

3be7664dd463c9ba7bc41cc55b05bba9152ca341

Project not found. Please check the 'sonar.projectKey' and 'sonar.organization' properties

When you try to build the project using `./mvnw clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonarit` gives the following error: ### Failed to execute goal org.sonarsource.scanner.maven:sonar-maven-plugin:3.8.0.2131:sonar (default-cli) on project java-design-patterns: Project not found. Please check the 'sonar.projectKey' and 'sonar.organization' properties, the 'SONAR_TOKEN' environment variable, or contact the project administrator Both in local and when you try to do the pull request. If the project is no longer in the sonarcloud, it can be a suggestion to remove the following dependencies: ``` <sonar.host.url>https://sonarcloud.io</sonar.host.url> <sonar.organization>iluwatar</sonar.organization> <sonar.projectKey>iluwatar_java-design-patterns</sonar.projectKey> <sonar.moduleKey>${project.artifactId}</sonar.moduleKey> <sonar.projectName>Java Design Patterns</sonar.projectName> ``` and to build using: `./mvnw clean verify` In order to continue to build the project and do pull request without building errors.

diff --git a/.github/workflows/maven-pr-builder.yml b/.github/workflows/maven-pr-builder.yml index 51ffbbcb9089..f2699a9c9c93 100644 --- a/.github/workflows/maven-pr-builder.yml +++ b/.github/workflows/maven-pr-builder.yml @@ -28,6 +28,7 @@ name: Java PR Builder on: pull_request: + pull_request_target: branches: [ master ] types: [ opened, reopened, synchronize ]

train

val

girolamo-giordano

train

iluwatar/java-design-patterns/2399_2402

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2399

iluwatar/java-design-patterns/2402

3be7664dd463c9ba7bc41cc55b05bba9152ca341

9262dc52b400845fae37e08ce17382de6f53ca75

Project not found. Please check the 'sonar.projectKey' and 'sonar.organization' properties

When you try to build the project using `./mvnw clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonarit` gives the following error: ### Failed to execute goal org.sonarsource.scanner.maven:sonar-maven-plugin:3.8.0.2131:sonar (default-cli) on project java-design-patterns: Project not found. Please check the 'sonar.projectKey' and 'sonar.organization' properties, the 'SONAR_TOKEN' environment variable, or contact the project administrator Both in local and when you try to do the pull request. If the project is no longer in the sonarcloud, it can be a suggestion to remove the following dependencies: ``` <sonar.host.url>https://sonarcloud.io</sonar.host.url> <sonar.organization>iluwatar</sonar.organization> <sonar.projectKey>iluwatar_java-design-patterns</sonar.projectKey> <sonar.moduleKey>${project.artifactId}</sonar.moduleKey> <sonar.projectName>Java Design Patterns</sonar.projectName> ``` and to build using: `./mvnw clean verify` In order to continue to build the project and do pull request without building errors.

diff --git a/.github/workflows/maven-pr-builder.yml b/.github/workflows/maven-pr-builder.yml index f2699a9c9c93..fb1fdbe84f7d 100644 --- a/.github/workflows/maven-pr-builder.yml +++ b/.github/workflows/maven-pr-builder.yml @@ -27,7 +27,6 @@ name: Java PR Builder on: - pull_request: pull_request_target: branches: [ master ] types: [ opened, reopened, synchronize ]

val

val

girolamo-giordano

train

iluwatar/java-design-patterns/2421_2429

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2421

iluwatar/java-design-patterns/2429

6205f7dd82098bc4bb2102dec3ec8747abe1fa59

95203520bc910fd7b4e261d30d8bc17f8d86104a

Translate event-driven-architecture readme file into Korean

I wanna translate `event-driven-architecture` readme file into Korean, if possible.

diff --git a/localization/ko/event-driven-architecture/README.md b/localization/ko/event-driven-architecture/README.md new file mode 100644 index 000000000000..0296076db582 --- /dev/null +++ b/localization/ko/event-driven-architecture/README.md @@ -0,0 +1,33 @@ +--- +title: Event Driven Architecture +category: Architectural +language: ko +tag: +- Reactive +--- + +## 의도 +이벤트 드리븐 아키텍처를 사용하는 다른 어플리케이션에 특정 객체의 상태 변화를 알리고 관련 이벤트를 발송할 수 있습니다. + +## 클래스 다이어그램 + + +## 적용 가능성 +아래와 같은 상황에서 이벤트 드리븐 아키텍처를 사용할 수 있습니다. + +* 느슨하게 연결된 시스템을 구축하고자 하는 경우 +* 반응형 시스템을 구축하고자 하는 경우 +* 확장성을 갖춘 시스템을 구축하고자 하는 경우 + +## 실제 적용 사례 + +* Chargify라는 결제 API에서는 다양한 이벤트를 통해 결제 활동을 드러냅니다. (https://docs.chargify.com/api-events) +* Amazon의 AWS Lambda에서는 Amazon S3 버킷에서의 변경, Amazon DynamoDB 테이블에서의 수정이나 어플리케이션 및 기기에서 발생한 커스텀 이벤트에 대응하여 코드를 실행할 수 있습니다. (https://aws.amazon.com/lambda) +* MySQL은 데이터베이스 테이블에서 발생하는 삽입이나 수정 이벤트를 기반으로 트리거를 실행합니다. + +## 크레딧 + +* [이벤트 드리븐 아키텍처 - 위키피디아](https://en.wikipedia.org/wiki/Event-driven_architecture) +* [이벤트 드리븐 아키텍처는 무엇인가?](https://aws.amazon.com/event-driven-architecture/) +* [실제 적용 사례/이벤트 드리븐 아키텍처](https://wiki.haskell.org/Real_World_Applications/Event_Driven_Applications) +* [이벤트 드리븐 아키텍처의 정의](http://searchsoa.techtarget.com/definition/event-driven-architecture)

train

val

hwan33

train

iluwatar/java-design-patterns/2428_2430

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2428

iluwatar/java-design-patterns/2430

6205f7dd82098bc4bb2102dec3ec8747abe1fa59

acf55c934f88a577d4ab2ba2297da3ab16bc9c23

Typo in javadoc of event-driven-architecture

I found some typos in javadoc. It's such a minor things, but I want to correct them.

diff --git a/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserCreatedEvent.java b/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserCreatedEvent.java index f7be8cb6cb0e..245f79b4cbca 100644 --- a/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserCreatedEvent.java +++ b/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserCreatedEvent.java @@ -29,9 +29,9 @@ import lombok.RequiredArgsConstructor; /** - * The {@link UserCreatedEvent} should should be dispatched whenever a user has been created. This - * class can be extended to contain details about the user has been created. In this example, the - * entire {@link User} object is passed on as data with the event. + * The {@link UserCreatedEvent} should be dispatched whenever a user has been created. + * This class can be extended to contain details about the user has been created. + * In this example, the entire {@link User} object is passed on as data with the event. */ @RequiredArgsConstructor @Getter diff --git a/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserUpdatedEvent.java b/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserUpdatedEvent.java index 57a5e4586e40..6fa1832cb4f9 100644 --- a/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserUpdatedEvent.java +++ b/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserUpdatedEvent.java @@ -29,9 +29,9 @@ import lombok.RequiredArgsConstructor; /** - * The {@link UserUpdatedEvent} should should be dispatched whenever a user has been updated. This - * class can be extended to contain details about the user has been updated. In this example, the - * entire {@link User} object is passed on as data with the event. + * The {@link UserUpdatedEvent} should be dispatched whenever a user has been updated. + * This class can be extended to contain details about the user has been updated. + * In this example, the entire {@link User} object is passed on as data with the event. */ @RequiredArgsConstructor @Getter diff --git a/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/EventDispatcher.java b/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/EventDispatcher.java index e5edd780a654..1d0fab9d5da7 100644 --- a/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/EventDispatcher.java +++ b/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/EventDispatcher.java @@ -53,7 +53,7 @@ public <E extends Event> void registerHandler( } /** - * Dispatches an {@link Event} depending on it's type. + * Dispatches an {@link Event} depending on its type. * * @param event The {@link Event} to be dispatched */ @@ -65,4 +65,4 @@ public <E extends Event> void dispatch(E event) { } } -} \ No newline at end of file +} diff --git a/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/Handler.java b/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/Handler.java index d81a5c04fcd0..8eb56ca0cb0b 100644 --- a/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/Handler.java +++ b/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/Handler.java @@ -34,7 +34,7 @@ public interface Handler<E extends Event> { /** * The onEvent method should implement and handle behavior related to the event. This can be as - * simple as calling another service to handle the event on publishing the event on a queue to be + * simple as calling another service to handle the event on publishing the event in a queue to be * consumed by other sub systems. * * @param event the {@link Event} object to be handled.

diff --git a/event-driven-architecture/src/test/java/com/iluwatar/eda/AppTest.java b/event-driven-architecture/src/test/java/com/iluwatar/eda/AppTest.java index f4d1f18a8d43..17f3bddaa4a2 100644 --- a/event-driven-architecture/src/test/java/com/iluwatar/eda/AppTest.java +++ b/event-driven-architecture/src/test/java/com/iluwatar/eda/AppTest.java @@ -35,7 +35,7 @@ class AppTest { /** * Issue: Add at least one assertion to this test case. - * + * <p> * Solution: Inserted assertion to check whether the execution of the main method in {@link App#main(String[])} * throws an exception. */

train

val

hwan33

train

iluwatar/java-design-patterns/2438_2439

iluwatar/java-design-patterns

iluwatar/java-design-patterns/2438