Transactional J2EE

We've already discussed EJB in detail, and there is extensive EJB literature available, so we will not belabor its value. J2EE provides EJB as a component translation layer that exists inside a container and provides most middle-tier services such as a transaction management layer, security, remote-client connectivity, and database connection pooling.

Fundamentally, EJB is a rudimentary transactional middleware environment that supports two types of components, or beans: session beans and entity beans. In short, session beans are nonpersistent, or transient, and can only link to one client for one session. An entity bean, by contrast, provides persistence.

If you are interested in mixing transactions and Java, you have JTA at your disposal, as well. JTA defines a high-level transaction management specification for distributed transaction processing. In addition, there is JTS, which is an API that provides links with other transactional resources such as TP monitors (e.g., BEA's Tuxedo or IBM's CICS). Although both JTA and JTS are important, they have not gotten the "traction" of EJB, despite their ability to do very different things.