Core J2EE™ Patterns: Best Practices and Design Strategies

Value Object

Context

Application clients need to exchange data with enterprise beans.

Problem

J2EE applications implement server-side business components as session beans and entity beans. Some methods exposed by the business components return data to the client. Often, the client invokes a business object's get methods multiple times until it obtains all the attribute values.

Session beans represent the business services and are not shared between users. A session bean provides coarse-grained service methods when implemented per the Session Facade pattern.

Entity beans, on the other hand, are multiuser, transactional objects representing persistent data. An entity bean exposes the values of attributes by providing an accessor method (also referred ...