java ByteBuffer和byte 数组相互转换

// Create a byte array

byte[] bytes = new byte[10];

// Wrap a byte array into a buffer

ByteBuffer buf = ByteBuffer.wrap(bytes);

// Retrieve bytes between the position and limit

// (see Putting Bytes into a ByteBuffer)

bytes = new byte[buf.remaining()];

// transfer bytes from this buffer into the given destination array

buf.get(bytes, 0, bytes.length);

// Retrieve all bytes in the buffer

buf.clear();

bytes = new byte[buf.capacity()];

// transfer bytes from this buffer into the given destination array

buf.get(bytes, 0, bytes.length);