2.3. Suspending and Resuming a Transaction

The JTA supports the concept of a thread temporarily suspending and resuming transactions to enable it to perform non-transactional work. The suspend method is called to temporarily suspend the current transaction associated with the calling thread. If the thread is not associated with any transaction, a null object reference is returned; otherwise, a valid Transaction object is returned. The Transaction object can later be passed to the resume method to reinstate the transaction context.

The resume method associates the specified transaction context with the calling thread. If the transaction specified is valid, the transaction context is associated with the calling thread. Otherwise, the thread is not associated with any transaction.

Transaction tobj = TransactionManager.suspend();
..
TransactionManager.resume(tobj);

Transaction tobj = TransactionManager.suspend();
..
TransactionManager.resume(tobj);

When a transaction is suspended, the application server de-registers and frees up the resources that are related to the suspended transaction. When a resource is de-listed, the Transaction Manager informs the resource manager and the resource manager disassociates the transaction from the specified resource object. When the application’s transaction context is resumed, the application server must give the transaction back its resources. Enlisting a resource as a result of resuming a transaction triggers the Transaction Manager to inform the resource manager to re-associate the resource object with the resumed transaction.