Convert ByteBuffer to byte array java [duplicate]

Answer 1

If hasArray() reports false then, calling array() will throw an exception.

In that case, the only way to get the data in a byte[] is to allocate a byte[] and copy the bytes to the byte[] using get(byte) or similar.

Answer 2

ByteBuffer exposes the bulk get(byte[]) method which transfers bytes from the buffer into the array. You'll need to instantiate an array of length equal to the number of remaining bytes in the buffer.

ByteBuffer buf = ...
byte[] arr = new byte[buf.remaining()];
buf.get(arr);