[Java知识库]NIO使用50MB操作5G文件

package org.demo;

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

public class Demo {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		FileInputStream fis=new FileInputStream("D:\\cc.MP4");
		FileOutputStream fos=new FileOutputStream("D:\\Copycc.MP4");
		FileChannel ic=fis.getChannel();
		FileChannel oc=fos.getChannel();
		ByteBuffer bf=ByteBuffer.allocateDirect(52428800);
		while (true) {
			bf.clear();
			int num=ic.read(bf);
			if (num<0) {
				break;
			}
			bf.flip();
			oc.write(bf);
		}
		System.out.println("下载成功");
	}

}