# JBoss Messaging Message Driven Bean Example

$Revision: 2751 $

## Overview

This example deploys a simple Message Driven Bean that processes messages sent to a test queue. Once it receives a message and "processes" it, the MDB sends an acknowledgment message to a temporary destination created by the sender for this purpose. The example is considered successful if the sender receives the acknowledgment message.
This example relies on having access to a running JBoss Messaging instance. The JBoss Messaging instance must be installed and started according to the "Installation" paragraph from the release documentation. However, the example will automatically deploy its own queue, unless a queue with the same name is already deployed.
This example also relies on having access to jboss-messaging-client.jar archive that comes with the release bundle. If you run this example from an unzipped installation bundle, the example run script is correctly configured to find the client jar. Otherwise, you must modify example's build.xml accordingly.

## Running the example

1. Set up the JBOSS_HOME environment variable to point to the JBoss instance you deployed JBoss Messaging into. For example, if you deployed JBoss Messaging in C:\jboss-4.2.0.GA\server\messaging\deploy, then your JBOSS_HOME value should be C:\jboss-4.2.0.GA.
2. Go to the example's home directory
cd ...\examples\mdb
3. Run the example:
ant
The output of a successful run should be similar to:

    $ ant
    Buildfile: build.xml

    identify:
         [echo] ###########################################################################
         [echo] #                        Running the MDB example                          #
         [echo] ###########################################################################
         [echo] The queue:      testQueue
         [echo] The client jar: ../../../output/lib/jboss-messaging-client.jar

    sanity-check:

    init:
        [mkdir] Created dir: C:\java\messaging\docs\examples\mdb\output\classes\META-INF
        [mkdir] Created dir: C:\java\messaging\docs\examples\mdb\output\lib\META-INF
        [mkdir] Created dir: C:\java\messaging\docs\examples\common\output\classes

    compile:
        [javac] Compiling 5 source files to C:\java\messaging\docs\examples\common\output\classes
        [javac] Compiling 2 source files to C:\java\messaging\docs\examples\mdb\output\classes

    jar:
         [copy] Copying 2 files to C:\java\messaging\docs\examples\mdb\output\classes\META-INF
          [jar] Building jar: C:\java\messaging\docs\examples\mdb\output\lib\mdb-example.jar

    deploy:
         [copy] Copying 1 file to C:\jboss-4.2.0.GA\server\messaging\deploy

    sleep:
         [echo] Sleeping for 5 seconds ...

    run:

    send:
         [java] Queue /queue/testQueue exists
         [java] The Hello! message was successfully sent to the testQueue queue
         [java] Received message: !olleH
         [java] The example connected to JBoss Messaging version 1.3.0.GA (1.3)
         [java]
         [java] #####################
         [java] ###    SUCCESS!   ###
         [java] #####################

    undeploy:
       [delete] Deleting: C:\jboss-4.2.0.GA\server\messaging\deploy\mdb-example.jar

    BUILD SUCCESSFUL
    Total time: 10 seconds

## Troublesooting

### 1. I get "javax.jms.JMSSecurityException: User null is NOT authenticated"

You probably didn't install JBoss Messaging correctly. A fresh JBoss Messaging installation requires changes in the security configuration of a default JBoss instance, specifically a properly configured "messaging" security domain. Follow the instructions from the "Installation" paragraph of the release documentation.