code: @RequestMapping(value = "/userSession", method = RequestMethod.GET)
      @ResponseBody
      public JsonObject<?> session(HttpServletRequest request) {
          JsonObject<?> ret = JsonObject.create();
          String cookieValueUsername = CookieUtils.getCookieValue(request,
                  UserWebConstant.CookieKey.USERNAME.getValue());
          String cookieValuePwd = CookieUtils.getCookieValue(request,
                  UserWebConstant.CookieKey.PWDMD5.getValue());
          if (LoginValidator.isValid(cookieValueUsername, cookieValuePwd)) {
              LOG.info("Already logon with username=" + cookieValueUsername);
              ret.addData("id", UserWebConstant.USERMAP.get(cookieValueUsername).getUserId());
              ret.addData("name", cookieValueUsername);
              return ret;
          } else {
              ret.setStatus(GlobalResponseStatusMsg.NOT_LOGIN.getCode());
              ret.addStatusInfo(GlobalResponseStatusMsg.NOT_LOGIN.getMessage().getMessage());
          }
  
          return ret;
      }
docs: 查看是否有session存在
  
  @param request 请求request
  
  @return JsonObject