Front Controller vs. Façade pattern

Question

Okay, I have done a bit of searching online and found this thread, but it still does not quite clear it up for me.

What exactly is the difference between a Front Control

Answer 1

The Front Controller pattern is an architectural pattern (it imposes an architectural structure upon your application).

The Façade pattern, in contrast, is a design pattern (it is used to structure a specific piece of functionality your application [a module], and does not force a structure upon your whole app).

Answer 2

The Front Controller pattern defines a single component that is responsible for processing application requests. Often used as a "bottleneck" to (for instance) channel requests through to consolidate standard behavior that needs to be performed each time.

See these links for short to the point explanations:

• http://java.sun.com/blueprints/patterns/FrontController.html
• http://www.oracle.com/technetwork/java/frontcontroller-135648.html
• http://martinfowler.com/eaaCatalog/frontController.html

A facade is on the other hand rather used to wrap other methods/services to provide a unified interface, hide complexity or reduce dependency on external systems (Exemplified in DDD's anti-corruption layer: http://www.goeleven.com/blog/entryDetail.aspx?entry=168), etc.

A facade is a thin wrapper that shouldn't contains any logic except the logic used to translate between the two systems. Front Controller has no such requirements.

See for instance: http://en.wikipedia.org/wiki/Facade_pattern

And to answer your questions concerning AppArchGuide: No, that's not correct.