public class NioTest4 {

    public static void main(String[] args) throws  Exception {

        FileInputStream inputStream = new FileInputStream("input.txt");

        FileOutputStream outputStream = new FileOutputStream("output.txt");

        FileChannel inputChannel = inputStream.getChannel();

        FileChannel outputChannel = outputStream.getChannel();

        ByteBuffer buffer =  ByteBuffer.allocate(1024);

        while (true){

            buffer.clear();

            int read = inputChannel.read(buffer);

            if( -1 == read){

                break;

            }

            buffer.flip();

            outputChannel.write(buffer);

        }

        inputChannel.close();

        outputChannel.close();

    }

}