public class IpFilter implements Filter {

  @Override
  public void init(FilterConfig filterConfig) throws ServletException {
  }

  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    final HttpServletResponse res = (HttpServletResponse) response;
    if (request.getRemoteAddr().equals("192.168.0.1")) {
      res.sendError(HttpServletResponse.SC_UNAUTHORIZED);
    }
  }

  @Override
  public void destroy() {
  }

}