Sams Teach Yourself J2EE™ in 21 Days

Writing a Simple Message-Driven Bean

As you work through this section, you will create a Message-driven bean that that simply prints out the contents of a text message on screen.

So that the Message-driven bean can work asynchronously you will employ the MessageListener interface. This interface and the associated onMessage() method, which is invoked each time a message is available at the destination, were fully described in Day 9.

Implementing the Interfaces

As already stated, all Message-driven beans must implement the MessageDrivenBean and MessageListener interfaces.

import javax.ejb.*;
import javax.jms.*;
public class MDBPrintMessage implements MessageDrivenBean, MessageListener {
// class body not shown – see listing 10.1
}

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