JMS 2.0 QueueBrowser on Wildfly does not return messages

Question

I have 2 simple EJB beans. The first one is a timer method that is called every second. In this method I add 10 random messages to a TestQueue.

@Singleton
@Startup
public class Timer {

    @Inject
    private JMSContext context;

    @Resource(mappedName = "java:/jms/queue/TestQueue")
    private Queue queue;

    @Schedule(hour = "*", minute = "*", second = "*/1", persistent = false)
    @AccessTimeout(unit = TimeUnit.DAYS, value = 1)
    public void addToQueue() {
        for(int i = 0; i<30; i++)
            context.createProducer().send(queue, "msg " + (new Random().nextInt(100)));
        printQueueSize();
    }

    public void printQueueSize() {
        QueueBrowser qb = context.createBrowser(queue);
        Enumeration enumeration = null;
        try {
            enumeration = qb.getEnumeration();
        } catch (JMSException e) {
            e.printStackTrace();
        }
        int size = 0;
        while(enumeration.hasMoreElements()) {
            enumeration.nextElement();
            size++;
        }

        System.out.println("Queue size: " + size);
    }
}

Second bean is a MDB consumer. I put Thread.sleep(100) to simulate long running task and make sure that there are some messages in TestQueue.

@MessageDriven(
activationConfig = {
        @ActivationConfigProperty(propertyName = "destination", propertyValue = "java:/jms/queue/TestQueue"),
        @ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
        @ActivationConfigProperty(propertyName = "maxSession", propertyValue = "1")
}) 
public class Consumer implements MessageListener {

    @Override
    public void onMessage(Message msg) {
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

The problem is that console output shows:

15:06:29,006 INFO  [stdout] (EJB default - 9) Queue size: 0
15:06:30,006 INFO  [stdout] (EJB default - 10) Queue size: 0
15:06:31,009 INFO  [stdout] (EJB default - 1) Queue size: 0

etc.

but in the wildfly admin console I can see that there are more and more messages every second:

The question is, why the QueueBrowser return empty Enumeration? Is it a bug in HornetQ implementation or there is some reason for that?

Answer 1

Although this will not answer your question, I will show how I get the queue size in HornetQ, in an EJB Service:

    InitialContext initialContext = null;
    try {
        // Step 1. Create an initial context to perform the JNDI lookup.
        initialContext = getContext();

        // Step 2. Perfom a lookup on the queue
        Queue queue = (Queue) initialContext.lookup("jmx/queue/YOUR_QUEUE_NAME");


        // Step 7. Use JMX to retrieve the message counters using the
        // JMSQueueControl
        ObjectName on = ObjectNameBuilder.DEFAULT
                .getJMSQueueObjectName(queue.getQueueName());
        JMXConnector connector = JMXConnectorFactory.connect(new JMXServiceURL("service:jmx:http-remoting-jmx://localhost:9990"), new HashMap<String, Object>());//this is the URL for WildFly 8.2 (should work for all 8.X)
        MBeanServerConnection mbsc = connector.getMBeanServerConnection();
        JMSQueueControl queueControl = MBeanServerInvocationHandler.newProxyInstance(mbsc, on, JMSQueueControl.class, false);

        // Step 8. List the message counters and convert them to
        // MessageCounterInfo data structure.
        String counters = queueControl.listMessageCounter();
        MessageCounterInfo messageCounter = MessageCounterInfo.fromJSON(counters);


        queueControl.getConsumerCount();//this returns consumer count
        queueControl.getMessagesAdded();//returns messages added from the last time we checked
        queueControl.isPaused();//prints out, whether the queue is paused (you can stop a queue from being processed e.g. from JMX)
        queueControl.getMessageCount();//message count so far

    } finally {
        // Step 17. Be sure to close our JMS resources!
        if (initialContext != null) {
            initialContext.close();
        }
    }