JMS Transactional Session Example

This example shows you how to use a transacted Session with ActiveMQ.

Firstly 2 messages are sent via the transacted sending session before being committed. This ensures that both message are sent

Secondly the receiving session receives the messages firstly demonstrating a message being redelivered after the session being rolled back and then acknowledging receipt of the messages via the commit method.

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 = 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 start the connection. In order for delivery to occur on any consumers or subscribers on a connection, the connection must be started
    6.            connection.start();
  6. We create a JMS session. The session is created as transacted.
    7.            Session session = connection.createSession(true, Session.SESSION_TRANSACTED);
  7. We create a JMS message producer on the session. This will be used to send the messages.
    8. 	   MessageProducer messageProducer = session.createProducer(queue);
  8. We create a message consumer
    9. 	   MessageConsumer messageConsumer = session.createConsumer(queue);
  9. We create 2 text messages
    10.            TextMessage message1 = session.createTextMessage("This is a text message1");
           TextMessage message2 = session.createTextMessage("This is a text message2");
  10. We send the text messages to the queue
    11.            messageProducer.send(message1);
           messageProducer.send(message2);
  11. We receive the message, it will return null as the transaction is not committed.
    12.            TextMessage receivedMessage = (TextMessage) messageConsumer.receive(5000);
  12. We commit the session
    13.            session.commit();
  13. We receive the messages again
    14.            receivedMessage = (TextMessage) messageConsumer.receive(5000);
  14. We roll back the session, this will cause the received message canceled and redelivered again
    15.  
           session.rollback();
  15. We receive the message again, we will get two messages. Nothing more, nothing less
    16.  
           receivedMessage = (TextMessage) messageConsumer.receive(5000);
           receivedMessage = (TextMessage) messageConsumer.receive(5000);
  16. We commit the session
    17.  
           session.commit();
  17. We receive the message again. Nothing should be received
    18.  
           receivedMessage = (TextMessage) messageConsumer.receive(5000);
  18. 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
    19.            finally
           {
              if (initialContext != null)
              {
                initialContext.close();
              }
              if (connection != null)
              {
                 connection.close();
              }
           }