It would be nice to add some improvements to the CacheFilter class in order to make it easier to have a sub-class.

"isCachable(request)" and "isCachable(response)" method could be called before to store a response into the cache, giving the possibility to implemented a custom algorithm in a sub-class.

A fine implementation of the method would be to test those "Pragme: no-cache" or "Cache-Control: private" response headers ...