public List<FileVo> listFile(String folderName) throws UpYunExcetion {
    sign.setUri(folderName);
    sign.setContentLength(0);
    sign.setMethod(HttpMethodEnum.GET.name());
    String url = autoUrl + sign.getUri();
    Map<String, String> headers = sign.getHeaders();

    HttpResponse httpResponse = HttpClientUtils.getByHttp(url, headers);
    String resultStr = null;
    if (httpResponse.getStatusLine().getStatusCode() != 200) {
      throw new UpYunExcetion(
          httpResponse.getStatusLine().getStatusCode(),
          httpResponse.getStatusLine().getReasonPhrase());
    } else {
      try {
        resultStr = EntityUtils.toString(httpResponse.getEntity());
      } catch (Exception e) {
        e.printStackTrace();
      }
    }

    String[] lines = resultStr.split("\n");
    String[] columns;
    List<FileVo> fileVoList = new ArrayList<FileVo>();
    FileVo fileVo;
    for (String line : lines) {
      columns = line.split("\t");
      fileVo = new FileVo();
      fileVo.setName(UrlCodingUtil.decodeBase64(columns[0]));
      fileVo.setIsFile(columns[1]);
      fileVo.setSize(Long.valueOf(columns[2]));
      fileVo.setUpdatedAt(new Date(Long.valueOf(columns[3]) * 1000));
      fileVoList.add(fileVo);
    }

    return fileVoList;
  }