code: public static long getFileSize(final FileSystem fs, final Path path, final PathFilter filter) throws IOException {
          long totalSize = 0l;
          for (final Path p : getAllFilePaths(fs, path, filter)) {
              totalSize = totalSize + fs.getFileStatus(p).getLen();
          }
          return totalSize;
      }
docs: /*public static String getSuffix(final String file) {
  if (file.contains("."))
  return file.substring(file.indexOf(".") + 1);
  else
  return "";
  }