things may be useful

ioutils.java

public static byte[] readFileUsingFileChannelAndMappedByteBuffer(Path file) {
  try(FileChannel ch = FileChannel.open(file, StandardOpenOption.READ)) {
    MappedByteBuffer mbb = ch.map(FileChannel.MapMode.READ_ONLY, 0, ch.size());
    byte[] bytes = new byte[mbb.remaining()];
    mbb.get(bytes);
    return bytes;
  }
}

regexps.txt

jvm method descriptor: ^\((\[*([ZBCDFIJS]|L([A-Za-z_]+\w*[/$]?)+;))*\)\[*([ZBCDFIJSV]|L([A-Za-z_]+\w*[/$]?)+;)$