OmniFaces Showcase

The HttpFilter is abstract filter specifically for HTTP requests. It provides a convenient abstract doFilter(HttpServletRequest, HttpServletResponse, HttpSession, FilterChain) method directly providing the HTTP servlet request, response and session, so that there's no need to cast them everytime in the doFilter(ServletRequest, ServletResponse, FilterChain) implementation. Also, default implementations of init(FilterConfig) and destroy() are provided, so that there's no need to implement them every time even when not really needed.

It's a bit the idea of using the convenient HttpServlet abstract servlet class instead of the barebones Servlet interface.

Usage

To use it, just let your custom filter extend from HttpFilter instead of implement Filter. For example:

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

    @Override
    public void doFilter(HttpServletRequest request, HttpServletResponse response, HttpSession session, FilterChain chain)
        throws ServletException, IOException
    {
        if (session != null && session.getAttribute("user") != null) {
            chain.doFilter(request, response);
        }
        else {
            Servlets.facesRedirect(request, response, "login.xhtml");
        }
    }
}