code: public String getDataString() {
          if (exception == null) {
              try {
                  if (!setDataString) {
                      dataString = EntityUtils.toString(httpEntity, charset.charset);
                      setDataString = true;
                  }
              } catch (IOException e) {
                  e.printStackTrace();
                  return null;
              }
          }
  
          return dataString;
      }
docs: 已字符串信息获取返回数据
  
  @return