code: @RequestMapping(method = RequestMethod.POST)
      @ResponseBody
      protected final String process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
  //        if(StrUtil.isBlank(legalStr(request))){
  //            return "";
  //        }
          String result = processRequest(request);
          response.getWriter().write(result);
          return null;
      }
docs: 微信消息交互处理
  
  @param request 请求
  @param response 响应
  @return 结果
  @throws ServletException servlet异常
  @throws IOException IO异常