Spring AOP - Annotation Based Before Advice

@Before is an advice type which ensures that an advice runs before the method execution. Following is the syntax of @Before advice.
@Pointcut("execution(* com.tutorialspoint.Student.getName(..))")
private void selectGetName(){}

@Before("selectGetName()")
public void beforeAdvice(){
   System.out.println("Going to setup student profile.");
} 
Where,
@Pointcut − Mark a function as a Pointcut
@Pointcut − Mark a function as a Pointcut
execution( expression ) − Expression covering methods on which advice is to be applied.
execution( expression ) − Expression covering methods on which advice is to be applied.
@Before − Mark a function as an advice to be executed before method(s) covered by Pointcut.
@Before − Mark a function as an advice to be executed before method(s) covered by Pointcut.
To understand the above-mentioned concepts related to @Before Advice, let us write an example which will implement @Before Advice. To write our example with few advices, let us have a working Eclipse IDE in place and use the following steps to create a Spring application −
Following is the content of Logging.java file. This is actually a sample of aspect module, which defines the methods to be called at various points.
package com.tutorialspoint;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.annotation.Before;

@Aspect
public class Logging {

   /** Following is the definition for a Pointcut to select
      *  all the methods available. So advice will be called
      *  for all the methods.
   */
   @Pointcut("execution(* com.tutorialspoint.Student.getName(..))")
   private void selectGetName(){}
   /** 
      * This is the method which I would like to execute
      * before a selected method execution.
   */
   @Before("selectGetName()")
   public void beforeAdvice(){
      System.out.println("Going to setup student profile.");
   }  
}
Following is the content of the Student.java file.
package com.tutorialspoint;

public class Student {
   private Integer age;
   private String name;

   public void setAge(Integer age) {
      this.age = age;
   }
   public Integer getAge() {
      System.out.println("Age : " + age );
      return age;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getName() {
      System.out.println("Name : " + name );
      return name;
   }
   public void printThrowException(){
      System.out.println("Exception raised");
      throw new IllegalArgumentException();
   }
}
Following is the content of the MainApp.java file.
package com.tutorialspoint;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");

      Student student = (Student) context.getBean("student");
      student.getName();
      student.getAge();     
   }
}
Following is the configuration file Beans.xml.
<?xml version = "1.0" encoding = "UTF-8"?>
<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" 
   xmlns:aop = "http://www.springframework.org/schema/aop"
   xsi:schemaLocation = "http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
   http://www.springframework.org/schema/aop 
   http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">

   <aop:aspectj-autoproxy/>

   <!-- Definition for student bean -->
   <bean id = "student" class = "com.tutorialspoint.Student">
      <property name = "name"  value = "Zara" />
      <property name = "age"  value = "11"/>      
   </bean>

   <!-- Definition for logging aspect -->
   <bean id = "logging" class = "com.tutorialspoint.Logging"/> 
</beans>
Once you are done creating the source and configuration files, run your application. Rightclick on MainApp.java in your application and use run as Java Application command. If everything is fine with your application, it will print the following message.
Going to setup student profile.
Name : Zara
Age : 11

The above-defined @Pointcut uses an expression to select method getAge() defined in class(es) under the package com.tutorialspoint. @After advice uses the above-defined Pointcut as a parameter. Effectively afterAdvice() method will be called before every method covered by the above Pointcut.
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