- Service Locator (315)
- Session Façde (341)
- Proxy [GoF]
- Adapter [GoF]
- Broker [POSA1]
The Business Delegate (302) typically uses a Service Locator (315) to encapsulate the implementation details of business service lookup. When the Business Delegate needs to look up a business service, it delegates the lookup functionality to the Service Locator (315).
For most EJB applications, the Business Delegate communicates with a Session Façde (341) and maintains a one-to-one relationship with that facade. Typically, the developer who implements a Session Façde (341) also provides corresponding Business Delegate implementations.
A Business Delegate can act as a proxy, providing a stand-in for objects in the business tier. The Delegate Proxy strategy provides this functionality.
A Business Delegate can use the Adapter design pattern to provide integration for otherwise incompatible systems.
A Business Delegate acts as a Broker to decouple the business-tier objects from the clients in other tiers.