ConnectionConsumer

 

The JMS specification enables an application server to integrate closely with a JMS implementation by using the ConnectionConsumer interface. This feature provides concurrent processing of messages. Typically, an application server creates a pool of threads, and the JMS implementation makes messages available to these threads. A JMS-aware application server (such as WebSphere Application Server) can use this feature to provide high-level messaging functionality, such as message driven beans.

Normal applications do not use the ConnectionConsumer, but expert JMS clients might use it. For such clients, the ConnectionConsumer provides a high-performance method to deliver messages concurrently to a pool of threads. When a message arrives on a queue or a topic, JMS selects a thread from the pool and delivers a batch of messages to it. To do this, JMS runs an associated MessageListener's onMessage() method.

We can achieve the same effect by constructing multiple Session and MessageConsumer objects, each with a registered MessageListener. However, the ConnectionConsumer provides better performance, less use of resources, and greater flexibility. In particular, fewer Session objects are required.

To help you develop applications that use ConnectionConsumers, WebSphere MQ JMS provides a fully-functioning example implementation of a pool. You can use this implementation without any changes, or adapt it to suit the specific needs of the application.

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