4 JMS Example

JOTM can be used with any JMS (Java Message Service) provider to gain advantage of both message-oriented architecture and distributed transactions.
This example uses JORAM (http://www.objectweb.org/joram/) as its JMS provider.

All Ant commands are to be executed from the examples/jms/ directory of a JOTM distribution (examples won't work from JOTM source directory).

4.1 Scenario

The jms example shows how to use JOTM with a JMS provider (in our case, JORAM) to provide distributed transactional messages.

• a RMI registry is started
• JOTM is started with UserTransaction and TransactionManager objects accessible through JNDI
• An application (SimpleJmsXa class) starts JORAM, setups the JMS objects (Queue, Session, ConnectionFactory) and registers them in JOTM as XA resources
• This application then starts a message sender, SimpleSender, and a message receiver, SimpleReceiver

On one hand, SimpleSender sends 4 messages on a JMS queue:

• one is outside a transaction
• one is inside a transaction with a commit result
• one is inside a transaction with a rollback result
• and the last one with a special text to stop SimpleReceiver

On the other hand, SimpleReceiver receives 3 messages from the same JMS queue:

• the one which was outside a transaction
• the one which was inside a transaction with a commit result
• the last one (with the special text)

(SimpleReceiver does not receive the 3rd sent message because it has been rolled back.)

4.2 Setup and compilation

To compile the example, type

$ ant compile

4.3 Run the example

First, you've to set JOTM_HOME to the directory of your JOTM distribution (e.g., ../jotm/output/dist from CVS).

$ export JOTM_HOME=<JOTM_distribution_directory>

To run the example, type in $JOTM_HOME/lib/

$ rmiregistry -J-classpath -Jjotm.jar:jotm_jrmp_stubs.jar \
  -J-Djava.security.policy=../config/java.policy &

Then in $JOTM_HOME/lib/, type

$ java -classpath jotm.jar:jotm_jrmp_stubs.jar:../config/ \
  org.objectweb.jotm.Main \
  -u UserTransaction -m TransactionManager&

(on one line)

And in the jms/ directory, type

$ ant run.jms

Since the client application of the jms example is a simple RMI/JRMP client, you've to use default protocol configuration for JOTM (i.e RMI/JRMP) in $JOTM_HOME/config/carol.properties file.

4.4 Output

the output of the jms example should be somethnig like

$ ...
$
$ [java] [SimpleJmsXa] lookup the TransactionManager.
$ [java] [SimpleJmsXa] start the JMS server.
$ [java] [SimpleJmsXa] JMS server started.
$ [java] [SimpleJmsXa] create JMS objects, register them in JOTM and bind them.
$ [java] [SimpleJmsXa] JMS objects available.
$ [java] [SimpleJmsXa] start simple sender.
$ [java] [SimpleSender] send : non transactional message
$ [java] [SimpleSender] send : transactional message with commit
$ [java] [SimpleSender] send : transactional message with rollback
$ [java] [SimpleSender] send : LAST message
$ [java] [SimpleJmsXa] start simple receiver.
$ [java] [SimpleReceiver] received: non transactional message
$ [java] [SimpleReceiver] received: transactional message with commit
$ [java] [SimpleReceiver] received: LAST message
$ [java] [SimpleJmsXa] JMS server stopped
$
$ ...

If SimpleSender has effectively sent 4 messages and SimpleReceiver has effectively received only 3 messages, then the jms example is working!