BEA Weblogic Interview Question:

How can an application do a JMS operation and have it succeed, independent of the result of the transaction?

Submitted by: Administrator

Basically, the JMS operation must be done using a transacted session or the transaction must be suspended/disabled as follows (pick one or more of the following).

1. Suspend the current transaction prior to making the JMS call and resume it after completing it. The code looks something like this:
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;

TransactionManager tranManager=
TxHelper.getTransactionManager();
Transaction saveTx = null;
try {
saveTx = tranManager.suspend();
... do JMS work, it will not participate in transaction
} finally {
// must always resume suspended transactions!
if (saveTx != null) tranManager.resume(saveTx);
}

2. Use a transacted session by specifying true for the first parameter to createQueueSession or createTopicSession.

3. Use a connection factory with user transactions disabled. That is, check that the UserTransactionsEnabled flag is explicitly set to false for the connection factory in the config.xml file or use the default for a user-configured connection factory for this value which is false. The pre-configured connection factory weblogic.jms.ConnectionFactory disables user transactions.

A transacted JMS session always has its own inner transaction. It is not affected by any transaction context that the caller may have. A non-transacted JMS session is more complicated. If you use the WLS 6.1 default factory weblogic.jms.ConnectionFactory, the session does not participate in a user transaction because the UserTransactionsEnabled flag is set to "False". If you use the deprecated default factory javax.jms.QueueConnectionFactory or javax.jms.TopicConnectionFactory or you define your own factory and set the UserTransactionsEnabled flag to "True", the JMS session participates in the outer transaction, if one exists and the JMS session is not transacted.
Submitted by: Administrator