RestfulActionMapper should return null for both getMapping(HttpServletRequest) and getUrlFromActionMapping(ActionMapping) method when it cannot handle the situation.

RestulActionMapper doesn't take into account namespace, say

eg.
if a namepace is specified in ActionMapping, RestfulActionMapper should return null when getUrlFromActionMapping(ActionMapping) is called.

eg.
if a request with extension is requested ( http://HOST/CONTEXT/ACTION.extension
ResfulActionMapper should return null when getMapping(HttpServletRequest) is invoked.

This is such that we could use CompositeActionMapper with ActionMapper like RestfulActionMapper and having DefaultActionMapper as the fallback ActionMapper. Generally i guess what I'm try to say is that ActionMapper should only handle the sitation that it could handle and return null if its out of its context such that we could cascade ActionMappers together using CompositeActionMapper.

cheers. :)