/**
     * This method simply calls <tt>negotiate( req, resp, false )</tt>
     * and then <tt>chain.doFilter</tt>. You can override and call
     * negotiate manually to achive a variety of different behavior.
     */
    @Override
    public void doFilter ( ServletRequest request, ServletResponse response, FilterChain chain ) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;

    /**
     * This method simply calls <tt>negotiate( req, resp, false )</tt>
     * and then <tt>chain.doFilter</tt>. You can override and call
     * negotiate manually to achive a variety of different behavior.
     */
    public void doFilter( ServletRequest request,
                ServletResponse response,
                FilterChain chain ) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest)request;