How to get number of pending message in a jms queue - jms

Question

Is there any way to get count number of pending messages in jms queue. My aim is to close the connection if there is no message remaining in the queue to process. how can i achieve this.
ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
Connection connection = connectionFactory.createConnection("admin", "admin");
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination destination = session.createQueue(subject);
MessageConsumer consumer = session.createConsumer(destination);
while (true) {
Message message = consumer.receive();
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
System.out.println("Incoming Message:: '" + textMessage.getText() + "'");
}
}

Answer 1

The only reliable way to get the true Queue count form the broker is to use the JMX MBean for the Queue and call the getQueueSize method.
The other programmatic alternative is to use the Statistics Broker Plugin which requires that you be able to change broker configuration to install it. Once installed you can send a special message to the control queue and get a response with details for the destination you want to monitor.
Using a QueueBrowser doesn't give you a true count because the browser has a max limit on how many messages it will page into memory to send you, so if your queue is deeper than the limit you won't get the actual size, just the value of the max page size limit.

Answer 2

I have done this by using createBrowser method below is my updated code.
public static void main(String[] args) throws JMSException {
ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
Connection connection = connectionFactory.createConnection("admin", "admin");
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination destination = session.createQueue(subject);
int queueSize = QueueConsumer.getQueueSize(session, (Queue) destination);
System.out.println("QUEUE SIZE: " + queueSize);
MessageConsumer consumer = session.createConsumer(destination);
for (int i = 0; i < queueSize; i++) {
Message message = consumer.receive();
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
System.out.println("Incomming Message: '" + textMessage.getText() + "'");
}
}
connection.close();
}
private int getQueueSize(Session session, Queue queue) {
int count = 0;
try {
QueueBrowser browser = session.createBrowser(queue);
Enumeration elems = browser.getEnumeration();
while (elems.hasMoreElements()) {
elems.nextElement();
count++;
}
} catch (JMSException ex) {
ex.printStackTrace();
}
return count;
}

Answer 3

I have done this with jmx it worked thanx #Tim Bish
here is my updated code
JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://0.0.0.0:44444/jndi/rmi://0.0.0.0:1099/karaf-root");
HashMap<String, String[]> environment = new HashMap<String, String[]>();
String[] creds = { "admin", "admin" };
environment.put(JMXConnector.CREDENTIALS, creds);
JMXConnector jmxc = JMXConnectorFactory.connect(url, environment);
MBeanServerConnection connection = jmxc.getMBeanServerConnection();
ObjectName nameConsumers = new ObjectName("org.apache.activemq:type=Broker,brokerName=amq,destinationType=Queue,destinationName=myqueue");
DestinationViewMBean mbView = MBeanServerInvocationHandler.newProxyInstance(connection, nameConsumers, DestinationViewMBean.class, true);
long queueSize = mbView.getQueueSize();
System.out.println(queueSize);

Answer 4

Just break the loop and close the connection if your JMS Message is null..
while (true) {
Message message = consumer.receive(2000);
if (message == null){
break;
}
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
System.out.println("Incoming Message:: '" + textMessage.getText() + "'");
}
}
connection.close();