converting bytes to integers in a bytebuffer

I have found this piece of code that I have posted below that should
convert bytes to integers, however I do not fully understand how this piece
of code works in java. I believe bytebuffer is used in this case in a full
piece of code as it is just a part I am struggling to understand.

public static byte[] intToBytes(int i) {
	return new byte[] {
		(byte) ((i & 0x000000FF) >> 0),
		(byte) ((i & 0x0000FF00) >> 8),           
		(byte) ((i & 0x00FF0000) >> 16),
		(byte) ((i & 0xFF000000) >> 24)
	};

public static int bytesToInt(byte[] bytes) {
    return ByteBuffer.wrap(bytes).getInt();
}