Bean IntegrationCamel supports the integration of beans with Camel message exchanges in a number of ways. Bean ComponentThe Bean component supports the creation of a proxy via ProxyHelper Then there is a server side implementation which consumes a message and uses the Bean Binding to bind the message to invoke a method passing in its parameters. Bean Post ProcessorIf a bean is defined in Spring XML and it has some Camel annotations then it can be processed to inject resources. Sendings messagesTo allow sending of messages you can use @EndpointInject() annotation e.g. lets send a message to the foo.bar queue in ActiveMQ at some point public class Foo { @EndpointInject(uri="activemq:foo.bar") ProducerTemplate producer; public void doSomething() { if (whatever) { producer.sendBody("<hello>world!</hello>"); } } } Consuming messagesTo consume a message you use a @MessageDriven e.g. lets invoke the onCheese() method with the String body of the inbound JMS message from ActiveMQ on the cheese queue; this will use the Type Converter to convert the JMS ObjectMessage or BytesMessage to a String - or just use a TextMessage from JMS public class Foo { @MessageDriven(uri="activemq:cheese") public void onCheese(String name) { ... } } Spring RemotingWe support a Spring Remoting provider which uses Camel as the underlying transport mechanism. The nice thing about this approach is we can use any of the Camel transport Components to communicate between beans. It also means we can use Content Based Router and the other Enterprise Integration Patterns in between the beans; in particular we can use Message Translator to be able to convert what the on-the-wire messages look like in addition to adding various headers and so forth. Bean bindingThe binding of a Camel Message to a bean method call can occur in different ways
You can also use the @Property For example you could write a method like this public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(String body) { // process the inbound message here } } Here Camel with subscribe to an ActiveMQ queue, then convert the message payload to a String (so dealing with TextMessage, ObjectMessage and BytesMessage in JMS), then process this method. You could process some headers if you wish like this public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@Header('JMSCorrelationID') String correlationID, @Body String body) { // process the inbound message here } } In the above you can now pass the Message.getJMSCorrelationID() as a parameter to the method (again with possible type conversion too). Finally you don't need the @MessageDriven annotation; as the Camel route could describe which method to invoke. e.g. a route could look like from("activemq:someQueue"). to("bean:myBean"); Here myBean would be looked up in the Registry (such as JNDI or the Spring ApplicationContext), then the body of the message would be used to try figure out what method to call. If you want to be explicit you can use from("activemq:someQueue"). to("bean:myBean?methodName=doSomething"); |