code: private byte[] readJobFile(FileStatus fileStatus) throws IOException {
      byte[] rawBytes = null;
      FSDataInputStream fsdis = null;
      try {
        long fileLength = fileStatus.getLen();
        int fileLengthInt = (int) fileLength;
        rawBytes = new byte[fileLengthInt];
        fsdis = hdfs.open(fileStatus.getPath());
        IOUtils.readFully(fsdis, rawBytes, 0, fileLengthInt);
      } finally {
        IOUtils.closeStream(fsdis);
      }
      return rawBytes;
    }
docs: Get the raw bytes and the last modification millis for this JobFile
  
  @return the contents of the job file.
  @throws IOException when bad things happen during reading