/**
  * 设置系统消息已读
  *
  * @return json
  */
 @RequestMapping("readSysMessage")
 @ResponseBody
 public JSONObject readSysMessage(HttpSession session) {
   User user = (User) session.getAttribute("user");
   if (user == null) {
     return AjaxReturn.Data2Ajax(0, "未登陆", null);
   }
   messageService.readSysMessage(user.getUser_id());
   return AjaxReturn.Data2Ajax(1, null, null);
 }