Enterprise JavaBeans, Second Edition

Explicit Transaction Management

Note

Although this section covers JTA, it is strongly recommended that you do not attempt to manage transactions explicitly. Through transaction attributes, EJB provides a comprehensive and simple mechanism for delimiting transactions at the method level and propagating transactions automatically. Only developers with a thorough understanding of transactional systems should attempt to use JTA with EJB.

In EJB, implicit transaction management is provided on the bean method level so that we can define transactions that are delimited by the scope of the method being executed. This is one of the primary advantages of EJB over cruder distributed object implementations: it reduces complexity and therefore programmer error. In addition, declarative transaction demarcation, as used in EJB, separates the transactional behavior from the business logic; a change to transactional behavior does not require changes to the business logic. In rare situations, however, it may be necessary to take control of transactions explicitly. To do this, it is necessary to have a much more complete understanding of transactions.

Explicit management of transactions is complex and is normally accomplished using the OMG’s OTS (Object Transaction Service) or the Java implementation of OTS, JTS ( Java Transaction Service). OTS and JTS provide APIs that allow developers to work with transaction managers and resources (databases) directly. While the JTS implementation of OTS is ...