用nio的ByteBuffer实现文件的拷贝

package niotest;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

/**
 * @program: javaio
 * @description: 新IO相关类练习
 * @author: Miller.FAN
 * @create: 2019-10-22 11:07
 **/
public class GetChannels {
    private static final int SIZE = 10*1024;

    public static void main(String[] args) throws Exception{
        FileChannel fc = new FileOutputStream("data.txt").getChannel();
        fc.write(ByteBuffer.wrap("Some text \n".getBytes()));
        fc.close();

        //从一个文件中读取信息到一个ByteBuffer
        FileChannel in = new FileInputStream("D:\\废弃代码\\network_monitoring\\network-monitoring-ue-big-data-task\\pom.xml").getChannel();
        ByteBuffer myBuf = ByteBuffer.allocate(SIZE);
        in.read(myBuf);
        myBuf.flip();   // 让myBuf准备好被读  主要是这个类中只维护了一个游标，读写共用
        //将myBuf中的信息写进data.txt
        FileChannel out = new RandomAccessFile("data.txt","rw").getChannel();
        out.position(out.size()); // 设置从末尾开始写
        out.write(myBuf);
        out.close();
        myBuf.clear();
        //展示写的结果
        fc = new FileInputStream("data.txt").getChannel();
        ByteBuffer buff = ByteBuffer.allocate(SIZE);
        fc.read(buff);
        buff.flip();
        while(buff.hasRemaining()) {
            System.out.print((char)buff.get());
        }
        fc.close();

        //有没有更简单的办法呢？ 当然有
        FileChannel my_in = new FileInputStream("D:\\废弃代码\\network_monitoring\\network-monitoring-ue-big-data-task\\pom.xml").getChannel(),
                my_out = new FileOutputStream("data2.txt").getChannel();
        my_in.transferTo(0,my_in.size(),my_out);
    }
}