The Java EE 6 Tutorial

Using Session Beans to Produce and to Synchronously Receive Messages

An application that produces messages or synchronously receives them can use a session bean to perform these operations. The example in An Application That Uses the JMS API with a Session Bean uses a stateless session bean to publish messages to a topic.

Because a blocking synchronous receive ties up server resources, it is not a good programming practice to use such a receive call in an enterprise bean. Instead, use a timed synchronous receive, or use a message-driven bean to receive messages asynchronously. For details about blocking and timed synchronous receives, see Writing the Clients for the Synchronous Receive Example.

Using the JMS API in an enterprise bean or web application is in many ways similar to using it in an application client. The main differences are the areas of resource management and transactions.

Resource Management

The JMS API resources are a JMS API connection and a JMS API session. In general, it is important to release JMS resources when they are no longer being used. Here are some useful practices to follow.

Transactions

Instead of using local transactions, you use container-managed transactions for bean methods that perform sends or receives, allowing the EJB container to handle transaction demarcation. Because container-managed transactions are the default, you do not have to use an annotation to specify them.

You can use bean-managed transactions and the javax.transaction.UserTransaction interface’s transaction demarcation methods, but you should do so only if your application has special requirements and you are an expert in using transactions. Usually, container-managed transactions produce the most efficient and correct behavior. This tutorial does not provide any examples of bean-managed transactions.