Enabling Rollback When an MSMQ Message Fails (Designing with Communication Adapters)

Designing with Communication Adapters

Enabling Rollback When an MSMQ Message Fails

To Roll back an Outbound MSMQ Message

In order to roll back an outbound MSMQ message when a failure occurs in the Java Collaboration Definition (for example, failure to insert a duplicate row into a database table that is defined to have unique keys), do the following:

Select Manual as the MSMQ Connection Mode in the outbound MSMQ adapter Connectivity Map properties .

Use the following JCD code:

try {
    MSMQClient_1.getEwayConfiguration().setOutMSMQName( "public" );
    MSMQClient_1.getEwayConfiguration().setOutMSMQShareMode( "DENY_RECEIVE_SHARE" );
    MSMQClient_1.getEwayConfiguration().setOutMSMQReceiveActionCode
( "ACTION_PEEK_CURRENT" );
    MSMQClient_1.connect();
    MSMQClient_1.getMSMQMessage();
    TestDB_1.getTEST1().insert();
    TestDB_1.getTEST1().setTESTSTRING( "From JCD" );
    TestDB_1.getTEST1().insertRow();
    MSMQClient_1.getEwayConfiguration().setOutMSMQReceiveActionCode
( "ACTION_RECEIVE" );
    MSMQClient_1.getMSMQMessage();
    MSMQClient_1.disconnect();
} catch ( Exception Catch ) {
    MSMQClient_1.disconnect();
}

The key code items are highlighted in bold. You must also use a try/catch block to catch the exception (for this example, the error is a failed insert to database).

Open the queue with the following settings:
- MSMQ Share Mode– DENY_RECEIVE_SHARE: This locks the queue so that other applications cannot open the queue in Receive mode. Until your application closes the queue, no other application can open the queue to receive the message.
- MSMQ Receive Action Code– ACTION_PEEK_CURRENT: This opens the queue so you can “peek” (view) the message.

Next, try a database update on the message you received from the queue. If this fails, move on to step 7 (close the queue instance). If that succeeds, change the adapter configuration properties to receive messages programmatically in this manner .

Next, receive the message. This removes the message from queue.

Disconnect from the queue.

Finally, close the queue using MSMQClient_1.disconnect(). This closes the current queue instance and unlocks the queue.