Chapter 139. Hazelcast Ringbuffer Component Available as of Camel version 2.16 Avalaible from Camel 2.16 The Hazelcast ringbuffer component is one of Camel Hazelcast Components which allows you to access Hazelcast ringbuffer. Ringbuffer is a distributed data structure where the data is stored in a ring-like structure. You can think of it as a circular array with a certain capacity. 139.1. Options The Hazelcast Ringbuffer component supports 3 options, which are listed below. Name Description Default Type hazelcastInstance (advanced) The hazelcast instance reference which can be used for hazelcast endpoint. If you don't specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance. HazelcastInstance hazelcastMode (advanced) The hazelcast mode reference which kind of instance should be used. If you don't specify the mode, then the node mode will be the default. node String resolveProperty Placeholders (advanced) Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true boolean The Hazelcast Ringbuffer endpoint is configured using URI syntax: with the following path and query parameters: 139.1.1. Path Parameters (1 parameters): Name Description Default Type cacheName Required The name of the cache String 139.1.2. Query Parameters (10 parameters): Name Description Default Type reliable (common) Define if the endpoint will use a reliable Topic struct or not. false boolean defaultOperation (producer) To specify a default operation to use, if no operation header has been provided. HazelcastOperation hazelcastInstance (producer) The hazelcast instance reference which can be used for hazelcast endpoint. HazelcastInstance hazelcastInstanceName (producer) The hazelcast instance reference name which can be used for hazelcast endpoint. If you don't specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance. String synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean concurrentConsumers (seda) To use concurrent consumers polling from the SEDA queue. 1 int onErrorDelay (seda) Milliseconds before consumer continues polling after an error has occurred. 1000 int pollTimeout (seda) The timeout used when consuming from the SEDA queue. When a timeout occurs, the consumer can check whether it is allowed to continue running. Setting a lower value allows the consumer to react more quickly upon shutdown. 1000 int transacted (seda) If set to true then the consumer runs in transaction mode, where the messages in the seda queue will only be removed if the transaction commits, which happens when the processing is complete. false boolean transferExchange (seda) If set to true the whole Exchange will be transfered. If header or body contains not serializable objects, they will be skipped. false boolean 139.2. Spring Boot Auto-Configuration The component supports 6 options, which are listed below. Name Description Default Type camel.component.hazelcast-ringbuffer.customizer.hazelcast-instance.enabled Enable or disable the cache-manager customizer. true Boolean camel.component.hazelcast-ringbuffer.customizer.hazelcast-instance.override Configure if the cache manager eventually set on the component should be overridden by the customizer. false Boolean camel.component.hazelcast-ringbuffer.enabled Enable hazelcast-ringbuffer component true Boolean camel.component.hazelcast-ringbuffer.hazelcast-instance The hazelcast instance reference which can be used for hazelcast endpoint. If you don't specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance. The option is a com.hazelcast.core.HazelcastInstance type. String camel.component.hazelcast-ringbuffer.hazelcast-mode The hazelcast mode reference which kind of instance should be used. If you don't specify the mode, then the node mode will be the default. node String camel.component.hazelcast-ringbuffer.resolve-property-placeholders Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true Boolean 139.3. ringbuffer cache producer The ringbuffer producer provides 5 operations: * add * readonceHead * readonceTail * remainingCapacity * capacity Header Variables for the request message: Name Type Description CamelHazelcastOperationType String valid values are: put, get, removevalue, delete CamelHazelcastObjectId String the object id to store / find your object inside the cache 139.3.1. Sample for put : Java DSL: from("direct:put") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.ADD)) .to(String.format("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX)); Spring DSL: <route> <from uri="direct:put" /> <log message="put.."/> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>add</constant> </setHeader> <to uri="hazelcast-ringbuffer:foo" /> </route> 139.3.2. Sample for readonce from head : Java DSL: from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.READ_ONCE_HEAD)) .toF("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX) .to("seda:out");

Commands:
hazelcast-ringbuffer:cacheName
from("direct:put") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.ADD)) .to(String.format("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX));
<route> <from uri="direct:put" /> <log message="put.."/> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>add</constant> </setHeader> <to uri="hazelcast-ringbuffer:foo" /> </route>
from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.READ_ONCE_HEAD)) .toF("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX) .to("seda:out");