Google Drive SDK API没有列出java中Google Drive上传的文件

I am creating an application which can insert files into Google Drive and lists it. I am using Google Drive SDK v2 API. But my problem is it is not listing files which is not uploaded through my application. If I upload directly from Google drive it is not listed in my application.

列出文件的方法如下:

private static List<File> retrieveAllFiles(Drive service) throws IOException {
        List<File> result = new ArrayList<File>();
        Files.List request = service.files().list();

        do {
          try {
            FileList files = request.execute();

            result.addAll(files.getItems());
            request.setPageToken(files.getNextPageToken());
          } catch (IOException e) {
            System.out.println("An error occurred: " + e);
            request.setPageToken(null);
          }
        } while (request.getPageToken() != null &&
                 request.getPageToken().length() > 0);

        return result;
      }

我正在迭代这样的文件:

List<File> files = retrieveAllFiles(service);
        for(File f : files) {
            System.out.println("File Name : "+f.getOriginalFilename();
        }