FileInputStream fInputStream=new FileInputStream(new File("/root/Desktop/testImage.jpg"));

        FileOutputStream fOutputStream =new FileOutputStream(new File("/root/Desktop/testImage2.jpg"));

        FileChannel fcIn=fInputStream.getChannel();

        FileChannel fcOut=fOutputStream.getChannel();

        ByteBuffer buffer=ByteBuffer.allocate(1024);

        //将管道的数据读入buffer中

        while(fcIn.read(buffer)!=-1){

            //由读操作转到写操作时必须调用flip来改变buffer的状态

            //内部操作：limit=position;position=0

            buffer.flip();

            //把buffer的数据写入管道

            fcOut.write(buffer);

            //清空buffer

            //内部操作：limit=capacity;position=0

            buffer.clear();

        }

        fcIn.close();

        fInputStream.close();

        fcOut.close();

        fOutputStream.close();