Java Utililty Methods File Read via ByteBuffer

final FileInputStream istream = new FileInputStream(from);
final FileChannel channel = istream.getChannel();
final StringWriter writer = new StringWriter();
final ByteBuffer buffer = ByteBuffer.allocate(1024 * 1024);
int read = 0;
while ((read = channel.read(buffer)) > 0) {
    writer.append(new String(buffer.array(), 0, read));
return writer.getBuffer().toString();

final FileInputStream stream = new FileInputStream(source);
try {
    final FileChannel fc = stream.getChannel();
    final MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
    return Charset.defaultCharset().decode(bb).toString();
} finally {
    stream.close();

final ByteBuffer buffer;
try {
    buffer = ByteBuffer.allocateDirect((int) channel.size());
    channel.read(buffer);
} finally {
    channel.close();
final byte[] result = new byte[buffer.flip().limit()];
...

if (length < 0) {
    throw new IllegalArgumentException("Length must not be negative: " + length);
int remaining = length;
while (remaining > 0) {
    final int location = length - remaining;
    final int count = input.read(buffer, offset + location, remaining);
    if (EOF == count) { 
...

ByteArrayOutputStream baos = new ByteArrayOutputStream();
fastCopy(stream, baos);
return baos;

return utf8(readBytes(file));

return getFileChannel(file, "r").map(FileChannel.MapMode.READ_ONLY, pos, length);

CharArrayWriter writer = new CharArrayWriter();
transfer(reader, writer);
return writer.toCharArray();

ByteBuffer tmp = ByteBuffer.allocate(4);
tmp.order(order);
if (order == ByteOrder.BIG_ENDIAN) {
    tmp.put((byte) 0x00);
    tmp.put(threeBytes[0]);
    tmp.put(threeBytes[1]);
    tmp.put(threeBytes[2]);
    return tmp.getInt(0);
...

log = "";
String output = "";
FileInputStream stream;
try {
    stream = new FileInputStream(input);
    try {
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
...