Java Utililty Methods File Read via ByteBuffer

try {
    byte[] data = new byte[4];
    is.read(data);
    int result = byteArrayToInt(data);
    if (result > SANITY_CHECK_MAX_INT) {
        throw new RuntimeException("Too large number");
    return result;
...

SeekableByteChannel channel = Files.newByteChannel(file, StandardOpenOption.READ);
ByteBuffer buffer = ByteBuffer.allocate((int) channel.size());
channel.read(buffer);
return (byte[]) buffer.flip().array();

return readBytes(channel, array, array.length);

ByteArrayOutputStream dataOut = new ByteArrayOutputStream();
FileChannel fChannel = new RandomAccessFile(file, "r").getChannel();
fChannel.transferTo(0, fChannel.size(), Channels.newChannel(dataOut));
fChannel.close();
return ByteBuffer.wrap(dataOut.toByteArray());

byte[] code = { message[0], message[1], message[2], message[3] };
return ByteBuffer.wrap(code).getInt();

List<byte[]> columnarKeyBlockDataList = new ArrayList<byte[]>(50);
ByteBuffer noDictionaryValKeyStoreDataHolder = ByteBuffer.allocate(columnarKeyBlockData.length);
noDictionaryValKeyStoreDataHolder.put(columnarKeyBlockData);
noDictionaryValKeyStoreDataHolder.flip();
while (noDictionaryValKeyStoreDataHolder.hasRemaining()) {
    short dataLength = noDictionaryValKeyStoreDataHolder.getShort();
    byte[] noDictionaryValKeyData = new byte[dataLength];
    noDictionaryValKeyStoreDataHolder.get(noDictionaryValKeyData);
...

if (!file.exists())
    throw new IOException("Source file does not exist");
FileInputStream stream = new FileInputStream(file);
try {
    FileChannel fc = stream.getChannel();
    MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
    return Charset.defaultCharset().decode(bb).toString();
} finally {
...

ByteBuffer bbuf;
FileChannel fc = input.getChannel();
bbuf = ByteBuffer.allocate((int) fc.size());
fc.read(bbuf);
bbuf.flip();
return decodeNIO ? decodeNIO(encoding, bbuf) : decodeIO(encoding, bbuf);

final RandomAccessFile fis = new RandomAccessFile(fileName, "r");
final FileChannel fc = fis.getChannel();
if (size < 0) {
    size = (int) fc.size();
MappedByteBuffer buf = fc.map(MapMode.READ_ONLY, 0, size);
final byte[] bytes = new byte[size];
buf.get(bytes);
...

byte[] sizeBytes = new byte[4];
int numRead = inputStream.read(sizeBytes, 0, 4);
if (numRead < 4) {
    throw new IOException("Failed to read the message size from the input stream!");
int messageLength = ByteBuffer.wrap(sizeBytes).getInt();
byte[] messageData = new byte[messageLength];
for (numRead = 0; numRead < messageLength;) {
...