5 Replies Latest reply on Aug 2, 2008 2:52 AM by Mahesh Lavannis

    Seam MDB example

    Mahesh Lavannis Newbie
      Since I could not find a simple example demonstrating Seam-MDB (Mesage Driven Bean) usage, I am posting one for the benefit of others. We will create a simple EJB3 MDB called "Phone" and send a message to it from a EJB3 stateless bean (I assume you know how to create and use stateless beans).

      In 3 steps:

      Step 1: Here is the code for the MDP (Phone.java):
      -----------------------------------------------------
      package com.mkl.message;

      import javax.jms.*;
      import javax.ejb.MessageDriven;
      import javax.ejb.ActivationConfigProperty;

      @MessageDriven(name="PhoneMessageBean", activationConfig = {
               @ActivationConfigProperty(propertyName="destinationType", propertyValue="javax.jms.Queue"),
               @ActivationConfigProperty(propertyName="destination", propertyValue="queue/phoneQueue")
           })
      public class Phone implements MessageListener {

           @Override
           public void onMessage(Message msg) {
                // TODO Auto-generated method stub
                TextMessage textMsg = (TextMessage) msg;
                try {
                     System.out.println("Received Phone Call:" + textMsg.getText());
                } catch (JMSException e) {
                     // TODO Auto-generated catch block
                     e.printStackTrace();
                }
           }
      }     
           


      -----------------------------------------------------

      Step 2: Here is the component addition to components.xml

      -----------------------------------------------------
      <component name="phoneQueueSender"
                class="org.jboss.seam.jms.ManagedQueueSender">
          <property name="queueJndiName">queue/phoneQueue</property>
      </component>

      -----------------------------------------------------

      Step 3: Here is the stateless bean function which sends a message
      (YOU NEED TO IMPORT javax.jms.*)
      -----------------------------------------------------
           @In(create=true)
           private transient QueueSender phoneQueueSender;  
           @In(create=true)
           private transient QueueSession queueSession;

           public void make_a_call (){
                 try
                 {
                    phoneQueueSender.send( queueSession.createTextMessage("You are in trouble"));
                 }
                 catch (Exception ex)
                 {
                     ex.printStackTrace();
                    throw new RuntimeException(ex);
                 }
                
           }

      -----------------------------------------------------