[FIXED] When would javax.servlet.Filter.doFilter(ServletRequest req, ServletResponse res) be called with anything other than HttpServletRequest/Response?

Issue

I've been writing servlets and filters for years and it is something that has always irked me a little - the checking and casting of ServletRequest and ServletResponse parameters to HttpServletRequest and HttpServletResponse, particularly with filters as there is no standard HttpFilter base class to do this for you - unlike servlets.

The question is - when would you ever see anything other that HttpServletRequest/HttpServletResponse being passed to your servlet/filter and what should you do if you do?

Solution

In some yet-to-be-realized world where there are other servlet types besides HttpServlets.

Answered By - user207421