Bean-Managed Transaction Suspension in J2EE

Get TransactionManager from a Custom Factory (WebSphere)

In WebSphere 4/5/6, a reference to TransactionManager should be obtained from a factory class. It is annoying, though, that the factory class name has changed between different WebSphere versions.

public TransactionManager getFromWebsphereFactory() 

        throws Exception {

     try {

        // WebSphere 5.1 or 6.0

        return 

            com.ibm.ws.Transaction.TransactionManagerFactory

                .getTransactionManager();

    }

    catch (ClassNotFoundException ex) {}

        

    try {

        // WebSphere 5.0

        return 

            com.ibm.ejs.jts.jta.TransactionManagerFactory

                .getTransactionManager();

    }

    catch (ClassNotFoundException ex) {}

        

    try {

        // WebSphere 4.0

        com.ibm.ejs.jts.jta.JTSXA..getTransactionManager();

    }

    catch (ClassNotFoundException ex) { }



    return null;

}

In WebLogic 7/8/9, a reference to TransactionManager can be obtained from the static method getTransactionManager(), defined in TxHelper in WebLogic 7. This class was deprecated in WebLogic 8 and TransactionHelper should be used instead.

public TransactionManager getFromWebLogicFactory() 

    throws Exception {

     try {

        // WebLogic 8/9

        return 

            weblogic.transaction.TransactionHelper

                .getTransactionManager();

    }

    catch (ClassNotFoundException ex) {}

        

    try {

        // WebLogic 7

        return 

            weblogic.transaction.TxHelper

                .getTransactionManager();

    }

    catch (ClassNotFoundException ex) {}

        

    return null;

}

Using TransactionManager

Once you've successfully obtained a reference to TransactionManager, you can use it for transaction suspension and resumption, as shown in the sample code below:

...

// obtain UserTransaction object and start transaction

InitialContext ctx = new InitialContext();

UserTransaction userTransaction = (UserTransaction)

    ctx.lookup("java:comp/UserTransaction");



// start first transaction

userTransaction.begin();

            

// obtain TransactionManager 

// using one of the methods described above

TransactionManager tm = getTransactionManager();



// suspend transaction

// suspend() returns reference to suspended

// Transaction object which later should be passed

// to resume()

Transaction transaction = tm.suspend();

                

// here you can do something outside of transaction

// or start new transaction, 

// do something and then commit or rollback

userTransaction.begin();

    

// commit subtransaction

userTransaction.commit();



// resume suspended transaction

tm.resume(transaction);



// commit first transaction

userTransaction.commit();

...