In Camel we have several really cool
Domain Specific Languages (DSLs) for easily expressing routing rules. But you don't need to learn these to use Camel. Starting with a POJO, you can use annotations to produce, consume or route messages to any
Camel endpoint.
Take the following bean for example
public class BeanThatTalksCamel {
@Produce(uri="activemq:myQueue")
ProducerTemplate producer;
@Consume(uri = "file:a/path")
public void onFileSendToQueue(String body) {
producer.sendBody(body);
}
}
We use the
@Consume annotation to mark onFileSendToQueue as a consumer of any messages coming from the file:a/path endpoint. To enable the bean to send messages to the activemq:myQueue endpoint, we use the
@Produce annotation. All conversions between Files, Strings and JMS Messages are automatic. Pretty easy huh?
We also have the
@RecipientList annotation that turns any bean into a dynamic
Recipient List.
public class RecipientListBean {
@Consume(uri = "activemq:myQueue")
@RecipientList
public List route(String body) {
// return list of recipients based on message body
}
}
Here we consume JMS messages from myQueue and based on the body, send it out to a list of recipients. Again, very easy. If you're a ServiceMix user,
Gert mentions how to use this trick from a ServiceMix perspective too, go check it out!
If you need more info, I've put all of these concepts into a little demo
here. As always, if you need help using Camel, please
get in touch.
I wrote up a little article on Apache Camel for DZone, go check it out!
