JMS Queue Example

This example shows you how to send and receive a message to a JMS Queue using ActiveMQ Artemis.

Queues are a standard part of JMS, please consult the JMS 1.1 specification for full details.

A Queue is used to send messages point to point, from a producer to a consumer. The queue guarantees message ordering between these 2 points.

Example step-by-step

To run the example, simply type mvn verify -Pexample from this directory

1. First we need to get an initial context so we can look-up the JMS connection factory and destination objects from JNDI. This initial context will get it's properties from the client-jndi.properties file in the directory ../common/config

           InitialContext initialContext = getContext();
        

2. We look-up the JMS queue object from JNDI

           Queue queue = (Queue) initialContext.lookup("/queue/exampleQueue");
        

3. We look-up the JMS connection factory object from JNDI

           ConnectionFactory cf = (ConnectionFactory) initialContext.lookup("/ConnectionFactory");
        

4. We create a JMS connection

           connection = cf.createConnection();
        

5. We create a JMS session. The session is created as non transacted and will auto acknowledge messages.

           Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        

6. We create a JMS message producer on the session. This will be used to send the messages.

          MessageProducer messageProducer = session.createProducer(topic);
       

7. We create a JMS text message that we are going to send.

           TextMessage message = session.createTextMessage("This is a text message");
        

8. We send message to the queue

           messageProducer.send(message);
        

9. We create a JMS Message Consumer to receive the message.

           MessageConsumer messageConsumer = session.createConsumer(queue);
        

10. We start the connection. In order for delivery to occur on any consumers or subscribers on a connection, the connection must be started

           connection.start();
        

11. The message arrives at the consumer. In this case we use a timeout of 5000 milliseconds but we could use a blocking 'receive()'

           TextMessage messageReceived = (TextMessage) messageConsumer.receive(5000);
        

12. And finally, always remember to close your JMS connections and resources after use, in a finally block. Closing a JMS connection will automatically close all of its sessions, consumers, producer and browser objects

           finally
           {
              if (initialContext != null)
              {
                initialContext.close();
              }
              if (connection != null)
              {
                 connection.close();
              }
           }