Chapter 122. Hazelcast Component
Available as of Camel version 2.7
The hazelcast- component allows you to work with the Hazelcast distributed data grid / cache. Hazelcast is a in memory data grid, entirely written in Java (single jar). It offers a great palette of different data stores like map, multi map (same key, n values), queue, list and atomic number. The main reason to use Hazelcast is its simple cluster support. If you have enabled multicast on your network you can run a cluster with hundred nodes with no extra configuration. Hazelcast can simply configured to add additional features like n copies between nodes (default is 1), cache persistence, network configuration (if needed), near cache, enviction and so on. For more information consult the Hazelcast documentation on http://www.hazelcast.com/docs.jsp.
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-hazelcast</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>122.1. Hazelcast components
See followings for each component usage: * map * multimap * queue * topic * list * seda * set * atomic number * cluster support (instance) * replicatedmap * ringbuffer
122.2. Using hazelcast reference
122.2.1. By its name
<bean id="hazelcastLifecycle" class="com.hazelcast.core.LifecycleService"
factory-bean="hazelcastInstance" factory-method="getLifecycleService"
destroy-method="shutdown" />
<bean id="config" class="com.hazelcast.config.Config">
<constructor-arg type="java.lang.String" value="HZ.INSTANCE" />
</bean>
<bean id="hazelcastInstance" class="com.hazelcast.core.Hazelcast" factory-method="newHazelcastInstance">
<constructor-arg type="com.hazelcast.config.Config" ref="config"/>
</bean>
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route id="testHazelcastInstanceBeanRefPut">
<from uri="direct:testHazelcastInstanceBeanRefPut"/>
<setHeader headerName="CamelHazelcastOperationType">
<constant>put</constant>
</setHeader>
<to uri="hazelcast-map:testmap?hazelcastInstanceName=HZ.INSTANCE"/>
</route>
<route id="testHazelcastInstanceBeanRefGet">
<from uri="direct:testHazelcastInstanceBeanRefGet" />
<setHeader headerName="CamelHazelcastOperationType">
<constant>get</constant>
</setHeader>
<to uri="hazelcast-map:testmap?hazelcastInstanceName=HZ.INSTANCE"/>
<to uri="seda:out" />
</route>
</camelContext>122.2.2. By instance
<bean id="hazelcastInstance" class="com.hazelcast.core.Hazelcast"
factory-method="newHazelcastInstance" />
<bean id="hazelcastLifecycle" class="com.hazelcast.core.LifecycleService"
factory-bean="hazelcastInstance" factory-method="getLifecycleService"
destroy-method="shutdown" />
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route id="testHazelcastInstanceBeanRefPut">
<from uri="direct:testHazelcastInstanceBeanRefPut"/>
<setHeader headerName="CamelHazelcastOperationType">
<constant>put</constant>
</setHeader>
<to uri="hazelcast-map:testmap?hazelcastInstance=#hazelcastInstance"/>
</route>
<route id="testHazelcastInstanceBeanRefGet">
<from uri="direct:testHazelcastInstanceBeanRefGet" />
<setHeader headerName="CamelHazelcastOperationType">
<constant>get</constant>
</setHeader>
<to uri="hazelcast-map:testmap?hazelcastInstance=#hazelcastInstance"/>
<to uri="seda:out" />
</route>
</camelContext>122.3. Publishing hazelcast instance as an OSGI service
If operating in an OSGI container and you would want to use one instance of hazelcast across all bundles in the same container. You can publish the instance as an OSGI service and bundles using the cache al need is to reference the service in the hazelcast endpoint.
122.3.1. Bundle A create an instance and publishes it as an OSGI service
<bean id="config" class="com.hazelcast.config.FileSystemXmlConfig">
<argument type="java.lang.String" value="${hazelcast.config}"/>
</bean>
<bean id="hazelcastInstance" class="com.hazelcast.core.Hazelcast" factory-method="newHazelcastInstance">
<argument type="com.hazelcast.config.Config" ref="config"/>
</bean>
<!-- publishing the hazelcastInstance as a service -->
<service ref="hazelcastInstance" interface="com.hazelcast.core.HazelcastInstance" />122.3.2. Bundle B uses the instance
<!-- referencing the hazelcastInstance as a service -->
<reference ref="hazelcastInstance" interface="com.hazelcast.core.HazelcastInstance" />
<camelContext xmlns="http://camel.apache.org/schema/blueprint">
<route id="testHazelcastInstanceBeanRefPut">
<from uri="direct:testHazelcastInstanceBeanRefPut"/>
<setHeader headerName="CamelHazelcastOperationType">
<constant>put</constant>
</setHeader>
<to uri="hazelcast-map:testmap?hazelcastInstance=#hazelcastInstance"/>
</route>
<route id="testHazelcastInstanceBeanRefGet">
<from uri="direct:testHazelcastInstanceBeanRefGet" />
<setHeader headerName="CamelHazelcastOperationType">
<constant>get</constant>
</setHeader>
<to uri="hazelcast-map:testmap?hazelcastInstance=#hazelcastInstance"/>
<to uri="seda:out" />
</route>
</camelContext>