Java NIO 文件通道使用

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();

    }

}