Using channels to pass data from outputStream to bytebuffer

Question

Is there a way to write data to an OutputStream object which is connected to a channel, and this channel will pass the data to a bytebuffer (preferably, direct bytebuffer)?

I have a situation where a third party function can write its output to an outputStream. I want to be able to write this data to a bytebuffer using channels.

Is it possible?

Thank you

Answer 1

You can easily create a class that extends OutputStream since this only requires one method to be implemented. Sample, untested code:

public final class ByteBufferOutputStream
    extends OutputStream
{
    private final ByteBuffer buf;

    public ByteBufferOutputStream(final int size)
    {
        buf = ByteBuffer.allocateDirect(size);
    }

    @Override
    public void write(final int b)
        throws IOException
    {
        if (buf.remaining() == 0)
            throw new IOException("buffer is full");
        buf.put((byte) (b & 0xff));
    }
}

Then just pass an instance of that class to your API. You'll also probably want to override the other write methods since ByteBuffer has dedicated methods to write byte arrays.