Message-Driven Bean using @Resource annotation

Question

I am trying to run a Message-Driven Bean very simple example in https://glassfish.dev.java.net/javaee5/ejb/examples/MDB.html
I configured MDBQueueConnectionFactory and MDBQueue properly on glassfish admin console.
I cannot run the example using @Resource annotation. I don't understand why.
@Resource(mappedName="MDBQueueConnectionFactory")
private static QueueConnectionFactory queueCF;
@Resource(mappedName="MDBQueue")
private static Queue mdbQueue;But I can run this example modifying the source code using InitialContext instance and looking up for JMS Resources.
InitialContext ctx = new InitialContext();
QueueConnectionFactory queueCF=(QueueConnectionFactory)ctx.lookup("MDBQueueConnectionFactory");
QueueConnection queueCon = queueCF.createQueueConnection();
Queue mdbQueue=(Queue)ctx.lookup("MDB");
queueSender.send(mdbQueue, msg);
...I want to figure out why @Resource annotation do not work well. Any help?
Thanks in advanced any help.

Answer 1

Thanks for your reply.
The error that I get is a simple NullPointerException. Nothing else.
Like you said, I develop a servlet and I can use @Resource annotation without static reference, and it works.
public class TestMDB extends HttpServlet {
     private static final long serialVersionUID = 1L;
     @Resource(mappedName="MDBQueueConnectionFactory")
     private QueueConnectionFactory queueCF;
     @Resource(mappedName="MDB")
     private Queue mdbQueue;
     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          PrintWriter out = response.getWriter();
          out.println("TEST MDB "+queueCF);
          QueueConnection queueCon;
          try {
               queueCon = queueCF.createQueueConnection();
               QueueSession queueSession = queueCon.createQueueSession
               (false, Session.AUTO_ACKNOWLEDGE);
               QueueSender queueSender = queueSession.createSender(null);
               TextMessage msg = queueSession.createTextMessage("hello");
               queueSender.send(mdbQueue, msg);
               out.println("Sent message to MDB");
               queueCon.close();
          } catch (JMSException e) {
               e.printStackTrace();
}But my question were about using @Resource annotation on a standalone client. I always get NullPointerException.
public class MDBClient {
    @Resource(mappedName="MDBQueueConnectionFactory")
    private static QueueConnectionFactory queueCF;
    @Resource(mappedName="MDB")
    private static Queue mdbQueue;
    public static void main(String args[]) {
     try {
            QueueConnection queueCon = queueCF.createQueueConnection();
            QueueSession queueSession = queueCon.createQueueSession
                (false, Session.AUTO_ACKNOWLEDGE);
            QueueSender queueSender = queueSession.createSender(null);
            TextMessage msg = queueSession.createTextMessage("hello");
            queueSender.send(mdbQueue, msg);
            System.out.println("Sent message to MDB");
            queueCon.close();
        } catch(Exception e) {
            e.printStackTrace();
}