JBoss AS7.1 - My Episode 1 - Learn about JMS 1.1 and EJB 3.1 Message-Driven Bean

Before we start with this episode, users need to know the difference between JBoss Community project and JBoss Enterprise Middleware Products.

JBoss AS7.1 community project driven by Red Hat

Implemented the JEE 6 specification, without ASL-based support, with the latest innovations, used by developers for testing and integrating middleware capacities and well suited for early to advanced pro typing and development

JBoss Enterprise Application Platform 6.0 product will be provided by Red Hat

Integrated, tested and certified Enterprise Platform. Subscription of such a product includes patches, updates, SLA-based support, multi-year maintenance policies, and also a Red Hat Open Source Assurance.

This a Best of both worlds - Rapid innovation, with long-term stability, supportability and maintainability

What is it?

This episode will show you and demonstrate the use of JMS 1.1 and EJB 3.1 Message-Driven Bean deployed in the JBoss Application Server 7.1

System requirements

To build successful this episode you need following softwares to be installed:

• Java 6.0 (Java SDK 1.6)
• for Solaris, Windows and Linux check this link http://www.oracle.com/technetwork/java/javase/index-137561.html
• for Mac read this blog https://gephi.org/users/install-java-6-mac-os-x-leopard/
• Maven 3.0.x is required. Please read this installation instructions http://maven.apache.org/download.html#Installation
• JBoss Application Server 7.1. get the last version (AS7.1.0CR1b) from here http://www.jboss.org/jbossas/downloads
• If you want to use Eclipse with JBoss Tools to run this episode, please download and install the version 3.7.1 of eclipse and the version 3.3.0.M5 of JBoss Tools from here http://download.jboss.org/jbosstools/updates/development/indigo/
• The applications this project produces is designed to be run on a JBoss AS 7.1.x

NOTE: This episode will use the already default configured connection factory named "InVmConnectionFactory" with the jndi "java:/ConnectionFactory" and a queue named "testQueue" with the jndi "queue/test". The artifacts will come from the JBoss Community Maven repository, a superset of the Maven central repository.

Code for this episode can be downloaded from here https://github.com/jbossas/quickstart/tree/master/helloworld-mdb

With the prerequisites out of the way, you're ready to build and deploy.

Application Structure

Our application consists of the following components:

• HelloWorldMDBServletClient: a servlet 3.0 application acts as client that sends several messages to a defined queue

• HelloWorldMDB: a message-driven bean that asynchronously receives and processes the messages that are sent to the queue by the servlet application

HelleworldMDBServletClient Servlet 3.0 class

this servlet application acts as client application and send several messages to a defined queue named "testQueue", that the message-driven bean application HelloWorldMDB listens to. Required components for sending messages are injection of the connection factory and the queue resources:

@Resource(mappedName = "java:/ConnectionFactory")

private static ConnectionFactory connectionFactory;

@Resource(mappedName = "java:/queue/test")

private static Queue queue;

the next action items will be to create connection, session and message produces in the servlet method doGet()

connection = connectionFactory.createConnection();

Session session = connection.createSession(false,Session.AUTO_ACKNOWLEDGE);

MessageProducer messageProducer = session.createProducer(queue);

Now we are ready to send several messages

TextMessage message = session.createTextMessage();

for (int i = 0; i < MSG_COUNT; i++) {

message.setText("This is message " + (i + 1));

messageProducer.send(message);

out.write("Message ("+i+"): " + message.getText() +"
");

}

Message-Driven Bean class

The HelloWorldMDB is a simple message-driven bean class uses the annotation @MessageDriven to define some very important properties like the "destinationType" and "destination", …

@MessageDriven(name = "HelloWorldMDB", activationConfig = {

@ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),

@ActivationConfigProperty(propertyName = "destination", propertyValue = "queue/test"),

@ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge")

}

)

public class HelloWorldMDB implements MessageListener {

…

The next action item will be to write the logic in the onMessage method. This method is invoked by the EJB container when the queue receives a message. The method onMessage is used for JMS API and is a method of the MessageListener Interface.

The onMessage method casts the incoming message to a TestMessage to display the text as String

public void onMessage(Message rcvMessage) {

TextMessage msg = null;

try {

if (rcvMessage instanceof TextMessage) {

msg = (TextMessage) rcvMessage;

LOGGER.info("Received Message: " + msg.getText());

} else {

LOGGER.warning("Message of wrong type: "

+ rcvMessage.getClass().getName());

}

} catch (JMSException e) {

throw new RuntimeException(e);

}

}

Deploying the application

First of all you need to enable the "admin" user from $JBOSS_HOME/standalone/configuration/mgmt-users.properties file, and then start JBoss AS 7.1.x. by running this script

$JBOSS_HOME/bin/standalone.sh

or if you are using windows

$JBOSS_HOME/bin/standalone.bat

To deploy the application, you first need to produce the archive to deploy using the following Maven goal:

mvn package

You can now deploy the artifact to JBoss AS by executing the following command:

mvn jboss-as:deploy

This will deploy target/jboss-as-helloworld-mdb.war.

The application will be running at the following URL http://localhost:8080/jboss-as-helloworld-mdb/HelloWorldMDBServletClient.

Go to the JBoss Application Server console or Server log and the result can look like this:

15:42:35,453 INFO class org.jboss.as.quickstarts.mdb.HelloWorldMDB) Received Message: This is message 1

15:42:35,455 INFO class org.jboss.as.quickstarts.mdb.HelloWorldMDB) Received Message: This is message 2

15:42:35,457 INFO class org.jboss.as.quickstarts.mdb.HelloWorldMDB) Received Message: This is message 3

15:42:35,478 INFO class org.jboss.as.quickstarts.mdb.HelloWorldMDB) Received Message: This is message 5

15:42:35,481 INFO class org.jboss.as.quickstarts.mdb.HelloWorldMDB) Received Message: This is message 4

To undeploy from JBoss AS, run this command:

mvn jboss-as:undeploy

You can also start JBoss AS 7 and deploy the project using Eclipse. See the JBoss AS 7 Getting Started Guide for Developers for more information.