The Java EE 5 Tutorial

JMS Destinations

A destination is the object a client uses to specify the target of messages it produces and the source of messages it consumes. In the PTP messaging domain, destinations are called queues. In the pub/sub messaging domain, destinations are called topics. A JMS application can use multiple queues or topics (or both). To learn how to create destination resources, see Creating JMS Administered Objects for the Synchronous Receive Example.

To create a destination using the Application Server, you create a JMS destination resource that specifies a JNDI name for the destination.

In the Application Server implementation of JMS, each destination resource refers to a physical destination. You can create a physical destination explicitly, but if you do not, the Application Server creates it when it is needed and deletes it when you delete the destination resource.

In addition to injecting a connection factory resource into a client program, you usually inject a destination resource. Unlike connection factories, destinations are specific to one domain or the other. To create an application that allows you to use the same code for both topics and queues, you assign the destination to a Destination object.

The following code specifies two resources, a queue and a topic. The resource names are mapped to destinations created in the JNDI namespace.

private static Queue queue;

private static Topic topic;

With the common interfaces, you can mix or match connection factories and destinations. That is, in addition to using the ConnectionFactory interface, you can inject a QueueConnectionFactory resource and use it with a Topic, and you can inject a TopicConnectionFactory resource and use it with a Queue. The behavior of the application will depend on the kind of destination you use and not on the kind of connection factory you use.