Applied Enterprise JavaBeans™ Technology

1.2. EJBs in the enterprise

EJBs, for all their power and flexibility, are most useful in conjunction with other components of an enterprise application. The J2EE model of enterprise application development—which is described in more detail below—sees EJBs as implementing the bulk of the application’s business logic and data management. In this model (Figure 1.1), EJBs occupy an architectural ‘tier’ between the enterprise data sources (relational databases, directory servers) and the presentation elements (clients using Java, servlets, etc). Centralizing the application’s business logic in EJBs allows a variety of different clients (including clients via CORBA protocols) to make use of that logic and decouples the application from the specific ...