/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.
 */

/**
 * The SimpleQueueSender class consists only of a main method, which sends several messages to a queue.
 * <p>
 * Run this program in conjunction with SimpleQueueReceiver. Specify a queue name on the command line when you run the
 * program.  By default, the program sends one message.  Specify a number after the queue name to send that number of
 * messages.
 */
package org.apache.activemq.demo;

// START SNIPPET: demo

import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSender;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class SimpleQueueSender {

   private static final Logger LOG = LoggerFactory.getLogger(SimpleQueueSender.class);

   private SimpleQueueSender() {
   }

   /**
    * Main method.
    *
    * @param args the queue used by the example and, optionally, the number of messages to send
    */
   public static void main(String[] args) {
      String queueName = null;
      Context jndiContext = null;
      QueueConnectionFactory queueConnectionFactory = null;
      QueueConnection queueConnection = null;
      QueueSession queueSession = null;
      Queue queue = null;
      QueueSender queueSender = null;
      TextMessage message = null;
      final int numMsgs;

      if ((args.length < 1) || (args.length > 2)) {
         LOG.info("Usage: java SimpleQueueSender " + "<queue-name> [<number-of-messages>]");
         System.exit(1);
      }
      queueName = args[0];
      LOG.info("Queue name is " + queueName);
      if (args.length == 2) {
         numMsgs = (Integer.valueOf(args[1])).intValue();
      } else {
         numMsgs = 1;
      }

      // Create a JNDI API InitialContext object if none exists yet.
      try {
         jndiContext = new InitialContext();
      } catch (NamingException e) {
         LOG.info("Could not create JNDI API context: " + e.toString());
         System.exit(1);
      }

      // Look up connection factory and queue. If either does not exist, exit.
      try {
         queueConnectionFactory = (QueueConnectionFactory) jndiContext.lookup("QueueConnectionFactory");
         queue = (Queue) jndiContext.lookup(queueName);
      } catch (NamingException e) {
         LOG.info("JNDI API lookup failed: " + e);
         System.exit(1);
      }

     /*
      * Create connection. Create session from connection; false means session is not transacted. Create sender and text
      * message. Send messages, varying text slightly. Send end-of-messages message. Finally, close connection.
      */
      try {
         queueConnection = queueConnectionFactory.createQueueConnection();
         queueSession = queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
         queueSender = queueSession.createSender(queue);
         message = queueSession.createTextMessage();
         for (int i = 0; i < numMsgs; i++) {
            message.setText("This is message " + (i + 1));
            LOG.info("Sending message: " + message.getText());
            queueSender.send(message);
         }

         // Send a non-text control message indicating end of messages.
         queueSender.send(queueSession.createMessage());
      } catch (JMSException e) {
         LOG.info("Exception occurred: " + e.toString());
      } finally {
         if (queueConnection != null) {
            try {
               queueConnection.close();
            } catch (JMSException e) {
            }
         }
      }
   }
}

// END SNIPPET: demo
