/*
* 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.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueRequestor;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.InitialContext;
import org.hornetq.api.jms.HornetQJMSClient;
import org.hornetq.api.jms.management.JMSManagementHelper;
import org.hornetq.common.example.HornetQExample;
/**
* An example that shows how to manage HornetQ using JMS messages.
*
* @author <a href="mailto:jmesnil@redhat.com">Jeff Mesnil</a>
*/
public class ManagementExample extends HornetQExample
{
public static void main(final String[] args)
{
new ManagementExample().run(args);
}
@Override
public boolean runExample() throws Exception
{
QueueConnection connection = null;
InitialContext initialContext = null;
try
{
// Step 1. Create an initial context to perform the JNDI lookup.
initialContext = getContext(0);
// Step 2. Perfom a lookup on the queue
Queue queue = (Queue)initialContext.lookup("/queue/exampleQueue");
// Step 3. Perform a lookup on the Connection Factory
QueueConnectionFactory cf = (QueueConnectionFactory)initialContext.lookup("/ConnectionFactory");
// Step 4.Create a JMS Connection
connection = cf.createQueueConnection();
// Step 5. Create a JMS Session
QueueSession session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
// Step 6. Create a JMS Message Producer
MessageProducer producer = session.createProducer(queue);
// Step 7. Create a Text Message
TextMessage message = session.createTextMessage("This is a text message");
System.out.println("Sent message: " + message.getText());
// Step 8. Send the Message
producer.send(message);
// Step 9. create the JMS management queue.
// It is a "special" queue and it is not looked up from JNDI but constructed directly
Queue managementQueue = HornetQJMSClient.createQueue("hornetq.management");
// Step 10. Create a QueueRequestor for the management queue (see queue-requestor example)
QueueRequestor requestor = new QueueRequestor(session, managementQueue);
// Step 11. Start the Connection to allow the queue requestor to receive replies
connection.start();
// Step 12. Create a JMS message which is used to send a management message
Message m = session.createMessage();
// Step 13. Use a helper class to fill the JMS message with management information:
// * the name of the resource to manage
// * in this case, we want to retrieve the value of the messageCount of the queue
JMSManagementHelper.putAttribute(m, "jms.queue.exampleQueue", "messageCount");
// Step 14. Use the requestor to send the request and wait for the reply
Message reply = requestor.request(m);
// Step 15. Use a helper class to retrieve the operation result
int messageCount = (Integer)JMSManagementHelper.getResult(reply);
System.out.println(queue.getQueueName() + " contains " + messageCount + " messages");
// Step 16. Create another JMS message to use as a management message
m = session.createMessage();
// Step 17. Use a helper class to fill the JMS message with management information:
// * the object name of the resource to manage (i.e. the queue)
// * in this case, we want to call the "removeMessage" operation with the JMS MessageID
// of the message sent to the queue in step 8.
JMSManagementHelper.putOperationInvocation(m,
"jms.queue.exampleQueue",
"removeMessage",
message.getJMSMessageID());
// Step 18 Use the requestor to send the request and wait for the reply
reply = requestor.request(m);
// Step 19. Use a helper class to check that the operation has succeeded
boolean success = JMSManagementHelper.hasOperationSucceeded(reply);
System.out.println("operation invocation has succeeded: " + success);
// Step 20. Use a helper class to retrieve the operation result
// in that case, a boolean which is true if the message was removed, false else
boolean messageRemoved = (Boolean)JMSManagementHelper.getResult(reply);
System.out.println("message has been removed: " + messageRemoved);
// Step 21. Create a JMS Message Consumer on the queue
MessageConsumer messageConsumer = session.createConsumer(queue);
// Step 22. Trying to receive a message. Since the only message in the queue was removed by a management
// operation,
// there is none to consume. The call will timeout after 5000ms and messageReceived will be null
TextMessage messageReceived = (TextMessage)messageConsumer.receive(5000);
System.out.println("Received message: " + messageReceived);
return true;
}
finally
{
// Step 23. Be sure to close the resources!
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
}
}
}