Servlet URL pattern case sensitivity

Question

I have the following code

@WebFilter(urlPatterns = "/path/to/directory/*")
public class PageFilter extends MyBaseFilter {

}

It works as expected if I do "http://localhost/path/to/directory", but if I do http://localhost/PATH/to/directory" or any other combination the filter does not work. It appears to be case sensitive. Is there a way to make this case insensitive so it matches any permutation of the url?

Answer 1

Is there a way to make this case insensitive so it matches any permutation of the url?

No.

But you can add another filter which sends a 301 (Permanent) redirect to a lowercased URI when the URI contains an uppercased character.

E.g.

@WebFilter("/*")
public class LowerCasedUriFilter extends HttpFilter {

    @Override
    public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws ServletException, IOException {
        var uri = request.getRequestURI();
        var lowerCasedUri = uri.toLowerCase();

        if (uri.equals(lowerCasedUri)) {
            chain.doFilter(request, response);
        }
        else {
            response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
            response.setHeader("Location", lowerCasedUri);
        }
    }
}

Make sure this filter is registered before yours.