/*
 * Copyright 2009 Red Hat, Inc.
 * Red Hat licenses this file to you under the Apache License, version
 * 2.0 (the "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *    http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.  See the License for the specific language governing
 * permissions and limitations under the License.
 */
package org.hornetq.jms.example;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.InitialContext;

import org.hornetq.common.example.HornetQExample;

/**
 * A simple JMS example that sends and consume message transactionally.
 *
 * @author <a href="hgao@redhat.com">Howard Gao</a>
 */
public class TransactionalExample extends HornetQExample
{
   public static void main(final String[] args)
   {
      new TransactionalExample().run(args);
   }

   @Override
   public boolean runExample() throws Exception
   {
      Connection connection = null;
      InitialContext initialContext = null;
      try
      {
         // Step 1. Create an initial context to perform the JNDI lookup.
         initialContext = getContext(0);

         // Step 2. Look-up the JMS topic
         Queue queue = (Queue)initialContext.lookup("/queue/exampleQueue");

         // Step 3. Look-up the JMS connection factory
         ConnectionFactory cf = (ConnectionFactory)initialContext.lookup("/ConnectionFactory");

         // Step 4. Create a JMS connection
         connection = cf.createConnection();

         // Step 5. Start the connection
         connection.start();

         // Step 6. Create a transactional JMS session
         Session session = connection.createSession(true, Session.SESSION_TRANSACTED);

         // Step 7. Create a JMS message producer
         MessageProducer messageProducer = session.createProducer(queue);

         // Step 8. Create a message consumer
         MessageConsumer messageConsumer = session.createConsumer(queue);

         // Step 9. Create 2 text messages
         TextMessage message1 = session.createTextMessage("This is a text message1");
         TextMessage message2 = session.createTextMessage("This is a text message2");

         // Step 10. Send the text messages to the queue
         messageProducer.send(message1);
         messageProducer.send(message2);

         System.out.println("Sent message: " + message1.getText());
         System.out.println("Sent message: " + message2.getText());

         // Step 11. Receive the message, it will return null as the transaction is not committed.
         TextMessage receivedMessage = (TextMessage)messageConsumer.receive(5000);

         System.out.println("Message received before send commit: " + receivedMessage);

         // Step 12. Commit the session
         session.commit();

         // Step 13. Receive the messages again
         receivedMessage = (TextMessage)messageConsumer.receive(5000);

         System.out.println("Message received after send commit: " + receivedMessage.getText());

         // Step 14. Roll back the session, this will cause the received message canceled and redelivered again.
         session.rollback();

         // Step 15. Receive the message again, we will get two messages
         receivedMessage = (TextMessage)messageConsumer.receive(5000);

         System.out.println("Message1 received after receive rollback: " + receivedMessage.getText());

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

         System.out.println("Message2 received after receive rollback: " + receivedMessage.getText());

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

         System.out.println("Message3 received after receive rollback: " + receivedMessage);

         // Step 16. Commit the session
         session.commit();

         // Step 17. Receive the message again. Nothing should be received.
         receivedMessage = (TextMessage)messageConsumer.receive(5000);

         if (receivedMessage != null)
         {
            // This was not supposed to happen
            return false;
         }

         System.out.println("Message received after receive commit: " + receivedMessage);

         return true;

      }
      finally
      {
         if (connection != null)
         {
            // Step 18. Be sure to close our JMS resources!
            connection.close();
         }
         if (initialContext != null)
         {
            // Step 19. Also close initial context!
            initialContext.close();
         }
      }
   }

}
