BytesConvertUtils.java

import java.util.function.Function;

public class BytesConvertUtils {
	public static final Function<Integer, byte[]> intToBytes = l -> {
		int count = Integer.BYTES;
		return new byte[] { (byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF) };
	};
	public static final Function<Float, byte[]> floatToBytes = intToBytes
			.compose(Float::floatToIntBits);
	public static final Function<byte[], Integer> bytesToInt = b -> {
		int count = Integer.BYTES;
		return ((b[8 - count] & 0xFF) << 8 * --count)
				| ((b[8 - count] & 0xFF) << 8 * --count)
				| ((b[8 - count] & 0xFF) << 8 * --count)
				| ((b[8 - count] & 0xFF) << 8 * --count);
	};
	public static final Function<byte[], Float> bytesToFloat = bytesToInt
			.andThen(Float::intBitsToFloat);
	public static final Function<Long, byte[]> longToBytes = l -> {
		int count = Long.BYTES;
		return new byte[] { (byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF),
				(byte) ((l >> 8 * --count) & 0xFF) };
	};
	public static final Function<Double, byte[]> doubleToBytes = longToBytes
			.compose(Double::doubleToLongBits);
	public static final Function<byte[], Long> bytesToLong = b -> {
		int count = Long.BYTES;
		return ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count)
				| ((b[8 - count] & 0xFFL) << 8 * --count);
	};
	public static final Function<byte[], Double> bytesToDouble = bytesToLong
			.andThen(Double::longBitsToDouble);
}