docs: public String getValueFromServer(String url) throws Exception {
  
          // 远程地址
          RemoteUrl remoteUrl = new RemoteUrl(url, hostList);
  
          ValueVo confItemVo = restfulMgr.getJsonData(ValueVo.class, remoteUrl, retryTime, retrySleepSeconds);
          LOGGER.debug("remote server return: " + confItemVo.toString());
  
          if (confItemVo.getStatus().equals(Constants.NOTOK)) {
              throw new Exception("status is not ok.");
          }
  
          return confItemVo.getValue();
      }