Enterprise JavaBeans 3.1, 6th Edition

Declarative Transaction Management

One of the primary advantages of Enterprise JavaBeans is that it allows for declarative transaction management. Without this feature, transactions must be controlled using explicit transaction demarcation, which involves the use of explicit APIs such as the Java Transaction Service (JTS). At best, explicit demarcation is difficult if you use the aforementioned APIs, particularly if you are new to transactional systems. In addition, it requires that the transactional code be written within the business logic, which reduces the clarity of the code. We talk more about explicit transaction management and EJB later in this chapter.

With declarative transaction management, the transactional behavior of EJBs can be controlled using the @javax.ejb.TransactionAttribute annotation or the EJB deployment descriptor, both of which can set transaction attributes for individual enterprise bean methods. This means that the transactional behavior of an EJB can be changed without changing the EJB’s business logic by simply annotating the method in a different way or modifying XML. Declarative transaction management reduces the complexity of transactions for EJB developers and application developers and makes it easier to create robust transactional applications. Where no explicit declarative transaction properties have been defined, EJB will provide a default (which we’ll soon see).

Transaction Scope

Transaction scope is a crucial concept for understanding transactions. ...