public void doFilter(ServletRequest request, ServletResponse response,
  FilterChain chain) throws IOException, ServletException {
  ServletRequest srequest = request;
  srequest.setCharacterEncoding(defaultEncode);
  String remoteAddr = srequest.getRemoteAddr();
  System.out.println("filter remote ip: "+remoteAddr);
  requests.set((HttpServletRequest) request);
  responses.set((HttpServletResponse) response);
  chain.doFilter(srequest, response);
  }
应该有所启示!