Java Transaction API 1.2 aka
(*), which is part of Java EE 7, adds 2 important new features :
Prior to JTA 1.2, transactions were delegated to EJBs. By doing that, the developer was shielded from doing low-level JTA/JTS transaction handling as all of this was transparently handeld by the EJB container. With CMT (
), the default behaviour, the EJB container intercept calls so that it can interpose the required transaction plumbings. So this was, on one hand, handy because transactions were basically managed transparently but it also required, on the other hand, to use EJBs.
@Transactional annotation solve this by basically bringing the semantics of those EJB transaction attributes in managed beans without any dependencies on the EJB container. So the
@Transactional annotation provides the ability to declaratively control transaction boundaries on managed beans. Under the hood, this capability is provided by a CDI interceptor that handle the necessary transaction plumbings (suspend, resume, commit, ...). In a nutshell,
@Transactional bring the ease of CMT transactions to various Java EE Components (Servlet, JAX-RS, etc.) without requiring to use EJBs.
annotation provides the ability to specify a standard CDI scope to define bean instances whose lifecycle is scoped to the currently active JTA transaction. This simple
code driven post
explain and demonstrate such a behaviour in action.
(*) For the curious who might wonder why some JSRs start in the 9xx range, there's a simple explanation for that. Those specifications are referred, in JCP parlance, as "
" because those specifications have originally been developed outside of the JCP.