JMS Scheduled Message Example

This example shows you how to send a scheduled message to a JMS Queue using ActiveMQ.

A Scheduled Message is a message that will be delivered at a time specified by the sender. To do this, simply set a HDR_SCHEDULED_DELIVERY_TIME header property. The value of the property should be the time of delivery in milliseconds.

In this example, a message is created with the scheduled delivery time set to 5 seconds after the current time.

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
    2.            InitialContext initialContext = getContext();
  2. We look-up the JMS queue object from JNDI
    3.            Queue queue = (Queue) initialContext.lookup("/queue/exampleQueue");
  3. We look-up the JMS connection factory object from JNDI
    4.            ConnectionFactory cf = (ConnectionFactory) initialContext.lookup("/ConnectionFactory");
  4. We create a JMS connection
    5.            connection = cf.createConnection();
  5. We create a JMS session. The session is created as non transacted and will auto acknowledge messages.
    6.            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.
    7.           MessageProducer producer = session.createProducer(queue);
  7. We create a JMS text message that we are going to send.
    8.            TextMessage message = session.createTextMessage("This is a scheduled message message which will be delivered in 5 sec.");
  8. We schedule the delivery time to be 5 sec later.
    9.            
            long time = System.currentTimeMillis();
            time += 5000;
            message.setLongProperty(MessageImpl.HDR_SCHEDULED_DELIVERY_TIME.toString(), time);
  9. We send message to the queue
    10.            messageProducer.send(message);
  10. We create a JMS Message Consumer to receive the message.
    11.            MessageConsumer messageConsumer = session.createConsumer(queue);
  11. We start the connection. In order for delivery to occur on any consumers or subscribers on a connection, the connection must be started
    12.            connection.start();
  12. We use a blocking receive() to consume the message and see when the message arrives.
    13.            TextMessage messageReceived = (TextMessage) messageConsumer.receive();
  13. 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
    14.            finally
           {
              if (initialContext != null)
              {
                initialContext.close();
              }
              if (connection != null)
              {
                 connection.close();
              }
           }

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