Core J2EE™ Patterns: Best Practices and Design Strategies

Session Facade

Context

Enterprise beans encapsulate business logic and business data and expose their interfaces, and thus the complexity of the distributed services, to the client tier.

Problem

In a multitiered J2EE application environment, the following problems arise:

• Tight coupling, which leads to direct dependence between clients and business objects;

• Too many method invocations between client and server, leading to network performance problems;

• Lack of a uniform client access strategy, exposing business objects to misuse.

A multitiered J2EE application has numerous server-side objects that are implemented as enterprise beans. In addition, some other arbitrary objects may provide services, data, or both. These objects are collectively referred ...