Sun Java System Application Server

The Message Driven Bean (MDB) Simple Sample Application

The Message Driven Bean (MDB) simple application provides an example of an MDB, which is an enterprise bean that allows Java Enterprise Edition (J2EE) applications to process messages asynchronously. An MDB acts as a JMS message listener, which is similar to an event listener except that it receives messages instead of events. The messages may be sent by any J2EE component (an application client, another enterprise bean, or a web component), or by a JMS application or system that does not use J2EE technology.

Building, Deploying, and Running the Application

The general instructions for building, deploying, and running sample applications are provided in Building, Deploying, and Running Sample Applications. In reading this document, use the following application-specific variables for this application:

install_dir is the directory where Application Server is installed.
app_dir is the application base directory: install_dir/samples/ejb/mdb/apps/simple.
appname is the application name: mdb-simple.
The prebuilt EAR file is mdb-simple.ear.

Follow this general procedure:

Build the Application. The build file, build.xml, is in the app_dir directory, specifically, install_dir/samples/ejb/mdb/apps/simple.
Configure JMS Resources
Deploy the Application. The EAR file is install_dir/samples/ejb/mdb/apps/simple/mdb-simple.ear.
Run the client, as described below.

Configuring JMS Resources

There are three ways to configure resources for this sample application:

By using asant. The build.xml file includes a predefined set of ant targets for configuring resources.
1. Change to directory install_dir/samples/ejb/mdb/apps/simple
2. Run asant deploy-jms-resource
3. Use Admin Console to to verify that the JMS resources are configured.
  Load this URL in your browser: http://hostname:admin-port
By using the Admin Console.
1. Load this URL in your browser: http://hostname:port/asadmin.
2. In the left pane, click Java Message Service.
3. Click Connection Factories. Click New in the right pane.
4. Add the following:
  - JNDI-Name: jms/MyMDBQcf
  - Type: javax.jms.QueueConnectionFactory
  - Resource: Select enabled checkbox
5. Click Destination Resources. Click New in the right pane.
6. Add the following:
  - JNDI-Name: jms/MyQueue
  - Type: javax.jms.Queue
  - Resource: Select enabled checkbox
7. Add a new property for this destination resource, using the name-value pair Name=MyQueue

By using asadmin:

For connection factory:

asadmin create-jms-resource --restype javax.jms.QueueConnectionFactory
--user username --password password  jms/MyMDBQcf

For destination(queue):

asadmin create-jms-resource  --restype javax.jms.Queue --user
amin-user --password admin-password
--property Name=MyQueue jms/MyQueue

Running the Client

To run the application:

Change your working directory to be the application base directory:
```
cd app_dir
```
If you are using the predeployed samples domain (Platform Edition only), enter this command to retrieve client stubs:
```
asadmin get-client-stubs --port 4858 --appname mdb-simple
```
This step is not required if you deployed the application yourself.

Run the application in the application client container:

install_dir/bin/appclient
 -client mdb-simpleClient.jar -name SimpleMessageClient
 -textauth -xml domain_root_dir/domain_name/config/sun-acc.xml

The results will be something like this:

Sending message: This is message 1
Sending message: This is message 2
Sending message: This is message 3

The MDB receives the messages, which are then printed in the log file server.log:

MESSAGE BEAN: Message received: This is message 1
MESSAGE BEAN: Message received: This is message 2
MESSAGE BEAN: Message received: This is message 3

For example, to run client in the samples domain, enter this command:

appclient -client mdb-simpleClient.jar
-name SimpleMessageClient -textauth
-xml install_dir/domains/samples/config/sun-acc.xml

Troubleshooting

If you encounter problems, in addition to viewing the Application Server log files, look at the MQ broker log files, for example:

MQ broker1 log: install_dir/domains/domain1/imq/instances/samplesbroker1/log/log.txt
MQ broker2 log: install_dir/domains/domain1/imq/instances/samplesbroker2/log/log.txt