JavaNIO实现文件复制

• NIO主要内容有Buffer、Channel、Charset及实现异步非阻塞IO的selector
• 这里通过使用IO流的getChannel()方法获取Channel，然后将文件内容映射到内存中获得Buffer 再将Buffer中的内容写入新的文件

package com.mark.learn.newio;

import java.io.*;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;

/**
 * Created by Mark on 2017/8/8.
 */
public class Splendid {
    public static void main(String[] args) {

        //测试复制图片
        String src="C:\\Users\\Mark\\Pictures\\Camera Roll\\na5.jpg";
        String des="d:\\na5.jpg";
        try {
            copyFileUseNIO(src,des);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    static void copyFileUseNIO(String src, String des) throws IOException {

        //IO流获取Channel
        FileChannel inChannel = new FileInputStream(src).getChannel();
        FileChannel outChannel = new FileOutputStream(des).getChannel();

        //将文件映射到内存
        MappedByteBuffer buffer = inChannel.map(FileChannel.MapMode.READ_ONLY, 0, new File(src).length());

        //写文件
        outChannel.write(buffer);
        System.out.println("Copy file "+src+"To"+des+"has been successfully complieted.");
        inChannel.close();
        outChannel.close();
    }
}