Java EE 8 Application Development

Container-managed transactions

Because EJB methods are transactional by default, we run into an interesting dilemma when an EJB method is invoked from client code that is already in a transaction. How should the EJB container behave? Should it suspend the client transaction, execute its method in a new transaction, and then resume the client transaction? Should it not create a new transaction and execute its method as part of the client transaction? Should it throw an exception?

By default, if an EJB method is invoked by client code that is already in a transaction, the EJB container will simply execute the session bean method as part of the client transaction. If this is not the behavior we need, we can change it by decorating the method ...