Facade Pattern

It hides the complexities of the system and provides an interface to the client from where the client can access the system.

The direct interaction of clients with subsystem classes leads to a high degree of coupling between the client objects and the subsystem. Whenever a subsystem class undergoes a change, such as a change in its interface, all of its dependent client classes may get affected.
The Façade pattern is useful in such situations and provides a higher level, simplified interface for a subsystem resulting in reduced complexity and dependency. This in turn makes the subsystem usage easier and more manageable.

Client interaction when we do not have a Facade

Client interaction with Facade

• See Facade pattern usage in J2EE applications.