2014-10-31 06:20:28 -04:00
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2014-11-19 03:44:57 -05:00
< title > ActiveMQ Java EE MDB Send Example< / title >
2014-10-31 06:20:28 -04:00
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< h1 > Java EE MDB TX Send Example< / h1 >
< p > This example shows you how to send a message to an MDB that returns a reply using the same XA transaction.< / p >
< p > The example will send deploy a simple MDB and demonstrate sending a message and the MDB consuming it.< / p >
< p > The example leverages the JBoss Arquillian framework to run a WildFly instance and deploy the MDB.< / p >
< h2 > Example step-by-step< / h2 >
< p > < i > download WildFly 8.0.0.Final from < a href = "http://wildfly.org/downloads/" > here< / a > and install.< / i > < / p >
< p > < i > set the JBOSS_HOME property to point to the WildFly install directory< / i > < / p >
< p > < i > type < code > mvn verify< / code > from the example directory to run< / i > < / p >
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< li > 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 < code > jndi.properties< / code > file in the directory < code > config< / code > < / li >
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final Properties env = new Properties();
env.put(Context.INITIAL_CONTEXT_FACTORY, "org.jboss.naming.remote.client.InitialContextFactory");
env.put(Context.PROVIDER_URL, "http-remoting://localhost:8080");
initialContext = new InitialContext(env);
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< li > We look up the JMS queue object from JNDI< / li >
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Queue queue = (Queue) initialContext.lookup("jms/queues/testQueue");
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< li > We look up the JMS connection factory object from JNDI< / li >
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ConnectionFactory cf = (ConnectionFactory)initialContext.lookup("/jms/RemoteConnectionFactory");
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< li > We create a JMS connection< / li >
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connection = cf.createConnection("guest", "password");
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< li > We create a JMS session. The session is created as non transacted and will auto acknowledge messages.< / li >
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< code > Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);< / code >
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< li > We create a JMS message producer on the session. This will be used to send the messages.< / li >
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< code > MessageProducer messageProducer = session.createProducer(queue);< / code >
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< li > We create a JMS text messages that we are going to send.< / li >
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< code > TextMessage message = session.createTextMessage("This is a text message");< / code >
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< li > We send messages to the queue< / li >
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< code > messageProducer.send(message);< / code >
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< li > The MDB receives the message< br / >
We know the message is a TextMessage so we cast to it.
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< code > TextMessage tm = (TextMessage)message;< / code >
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< li > The MDB gets the text and prints it
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< code > String text = tm.getText();
System.out.println("message " + text + " received");
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< li > The MDB creates a JMS connection
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< code > conn = connectionFactory.createConnection();
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< li > The MDB creates a JMS session
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< code > Session sess = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
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< li > The MDB creates a JMS message producer
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< code > MessageProducer producer = sess.createProducer(replyQueue);
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< li > The MDB creates a text message and sends it to the reply queue
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< code > producer.send(sess.createTextMessage("this is a reply"));
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< li > The Client creates a JMS message consumer using the injected reply queue
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< code > MessageConsumer messageConsumer = session.createConsumer(replyQueue);
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< li > The Client starts the connection so it can receive messages
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< code > connection.start();
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< li > The Client receives the reply and prints it out
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< code > message = (TextMessage) messageConsumer.receive(5000);
System.out.println("message.getText() = " + message.getText());
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< li > And finally, < b > always< / b > remember to close your JMS connections and resources after use, in a < code > finally< / code > block. Closing a JMS connection will automatically close all of its sessions, consumers, producer and browser objects< / li >
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< code > finally
{
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
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