The Java EE 5 Tutorial

JMS Message Selectors

If your messaging application needs to filter the messages it receives, you can use a JMS API message selector, which allows a message consumer to specify the messages it is interested in. Message selectors assign the work of filtering messages to the JMS provider rather than to the application. For an example of an application that uses a message selector, see A Java EE Application That Uses the JMS API with a Session Bean.

A message selector is a String that contains an expression. The syntax of the expression is based on a subset of the SQL92 conditional expression syntax. The message selector in the example selects any message that has a NewsType property that is set to the value 'Sports' or 'Opinion':

NewsType = ’Sports’ OR NewsType = ’Opinion’

The createConsumer, createDurableSubscriber methods allow you to specify a message selector as an argument when you create a message consumer.

The message consumer then receives only messages whose headers and properties match the selector. (See Message Headers, and Message Properties.) A message selector cannot select messages on the basis of the content of the message body.