In the message-driven bean (RockSurveyMDBean), the persistence related instance variables and the persist(), doCommit(), and doRollback() methods are transferred wholesale from RockSurvey2Bean (see Example: The Rock Survey, Take 2 and Example: The Rock Survey, Take 2 (continued)). Since MDBs don't have a SessionContext, the MessageDrivenContext is used instead to get the UserTransaction object:

    ut = mdc.getUserTransaction(); 

     And now, what you've all been waiting for: the MDB's onMessage() method:

  public void onMessage( Message msg ) 
  {
    try 
    {
      if( msg instanceof TextMessage ) 
      {
        TextMessage tm = (TextMessage)( msg );
        System.out.println( "Message received: " +
                             tm.getText() );
        return;
      }

      if( msg instanceof ObjectMessage ) 
      {
        System.out.println( "RockSurveyData " + 
                            "ObjectMessage received. " );
        ObjectMessage om = (ObjectMessage)( msg );
        rsd = (RockSurveyData)om.getObject();

        if( persist() )
        {
          System.out.println( "Table data persisted, " );
        }
        else 
        {
          System.out.println( "Problem persisting data." );
        }
        return;
      }
      else 
      {
        System.out.println( "Unknown Message type: " + 
                             msg.getClass().getName() );
      }
    }
    catch( JMSException jmse ) 
    {
      System.out.println( "JMSException: " + 
                           jmse.getMessage() );
                           jmse.printStackTrace();
    }
  } // end onMessage

     onMessage() is prepared to handle TextMessage and ObjectMessage type messages. If it receives a TextMessage, the text is extracted and printed. For ObjectMessages, the contained object is retrieved into a RockSurveyData. Then the persist() method is invoked to update the database and the result is printed. Any other message types are noted and then ignored.