Head First EJB

Scenario Summary

Transaction Scenarios

A CMT bean calls context.getUserTransaction().

The bean gets an IllegalStateException. (Only BMT beans can get a UserTransaction)

Client calls remove() on a stateful bean that is still in an open transaction.

The client gets a RemoveException. You can’t remove a stateful bean while its in a transaction. (Which is just one of a gazillion reasons why it’s a Bad Idea to leave a transaction open across multiple client invocations. In other words, if you begin a BMT transaction in a method, you should end it in that method!)

A CMT bean calls getRollbackOnly(), from a method marked NotSupported.

The bean gets an IllegalStateException. You must be in a transaction when you call getRollbackOnly() or setRollbackOnly(). That means you can’t call them within a method marked NotSupported, Never, or Supports (session and entity beans) or NotSupported (message-driven beans—remember, message-driven beans can’t use Never or Supports, because they don’t make sense given that transactions can never propagate into a message-driven bean.)

Client calls a method on a Remote CMT bean, and the method is marked Mandatory. The caller does not have a transaction context in place when the call comes in.

The client gets a TransactionRequiredException (a local client would get TransactionRequiredLocalException).

A session bean wants the Container to know that the transaction should be rolled back and the bean should be killed.

The bean should throw an EJBException. The Container ...