Caching Filter
Minimize repeated page generation by caching dynamic pages when they are generated (Figure A-13).
A common interface implemented by the cache, decorators and target.
Intercepts all requests and replies efficiently with cached pages if available. If no cached data is available, caches the results of generating the page.
Encapsulate a piece of common functionality, while presenting the same interface as the target.
The final object in the request processing chain. Coordinates all specific activities, such as input handling. Typically the front controller (Figure A-14).