How to put the content of a ByteBuffer into an OutputStream?

Question

I need to put the contents of a java.nio.ByteBuffer into an java.io.OutputStream. (wish I had a Channel instead but I don't) What's the best way to do this?

I can't use the ByteBuffer's array() method since it can be a read-only buffer.

I also may be interspersing writes to the OutputStream between using this ByteBuffer and having a regular array of byte[] which I can with use OutputStream.write() directly.

Answer 1

Look at Channels.newChannel(OutputStream). It will give you a channel given an OutputStream. With the WritableByteChannel adapter you can provide the ByteBuffer which will write it to the OutputStream.

public void writeBuffer(ByteBuffer buffer, OutputStream stream) {
   WritableByteChannel channel = Channels.newChannel(stream);

   channel.write(buffer);
}

This should do the trick!