Checking message in the JMS queue

Question

Hi there,
Is there a way to check the message is in the JMS queue? I tried to use the QueueBrowser. However, it always return me an enumeration = null
when I run the following "QueueBrowser.getEnumeration()". I am using JRun 3.0 application server.
And by the way, how would to know whether the message has been consumed by the receiver in a point to point model? We could still managed to send out messages even when the receiver client is not started. I understand that the receiver client would be able to receive those messages once they are started as the messages are in the queue. However, what if the queue is destroyed (some catastrophic event happen to the JMS provider) before the receiver client is started?

Answer 1

I have no problem using the QueueBrowser:
      QueueConnection qc;
      qc = qcf.createQueueConnection();
      QueueSession session;
      session = qc.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
      QueueBrowser browser = session.createBrowser(queue);
      Enumeration enum = browser.getEnumeration();The used JMS provider must support a persistence mode. When the server is restarted and there were messages in the queue, they are restored.
When receiving messages you can use autoacknowledge mode without transaction which means when receive() is called, the message is deleted from the queue. In transacted mode in addition to receive() you have to call commit() on the session in order to delete the message in the queue.
When using clientacknowledge you have to call message.acknowlegde() after receive().