7 Using EJB 3.0 Compliant MDBs

Example 7-1 Non-Injected Resources MDB Example

package test;
 
import javax.annotation.Resources;
import javax.annotation.Resource;
import javax.naming.*;
import javax.ejb.*;
import javax.jms.*;
 
import weblogic.javaee.MessageDestinationConfiguration;
import weblogic.javaee.TransactionTimeoutSeconds;
 
@MessageDriven(
  name = "MyMDB",
  mappedName = "JNDINameOfMDBSourceDest"
)
 
// optionally specify a connection factory
// there's no need to specify a connection factory if the source
// destination is a WebLogic JMS destination
 
@MessageDestinationConfiguration( 
  connectionFactoryJNDIName = "JNDINameOfMDBSourceCF"  
)
 
// optionally set a tx timeout, the default timeout is typically 30 seconds
 
@TransactionTimeoutSeconds(value = 60) 
 
// resources that are not injected
 
@Resources ({
  @Resource(name="targetCFRef", 
            mappedName="TargetCFJNDIName",
            type=javax.jms.ConnectionFactory.class), 
 
  @Resource(name="targetDestRef",
            mappedName="TargetDestJNDIName",
            type=javax.jms.Destination.class)
})
 
 
public class MyMDB implements MessageListener {
 
  // inject a reference to the MDB context
 
  @Resource
  private MessageDrivenContext mdctx;  
 
  // cache targetCF and targetDest for re-use (performance) 
 
  private ConnectionFactory targetCF;
  private Destination targetDest;
 
  @TransactionAttribute(TransactionAttributeType.REQUIRED)
  public void onMessage(Message message) {
 
    Connection jmsConnection = null;
 
    try {
      System.out.println("My MDB got message: " + message);
 
      if (targetCF == null) 
        targetCF = (javax.jms.ConnectionFactory)mdctx.lookup("targetCFRef");
 
      if (targetDest == null)
        targetDest = (javax.jms.Destination)mdctx.lookup("targetDestRef");
 
      jmsConnection = targetCF.createConnection();
      Session s = jmsConnection.createSession(false, Session.AUTO_ACKNOWLEDGE);
      MessageProducer mp = s.createProducer(null);
 
      if (message.getJMSReplyTo() != null) 
        mp.send(message.getJMSReplyTo(), s.createTextMessage("My Reply"));
      else
        mp.send(targetDest, message);
      
    } catch (JMSException e) {
      throw new EJBException(e); 
 
    } finally {
 
      // Return JMS resources to the resource reference pool for later re-use.
      // Closing a connection automatically also closes its sessions, etc.
 
      try { if (jmsConnection != null) jmsConnection.close(); }
      catch (JMSException ignored) {};
    }
  }
}