package com.cppdy.nio;

import java.nio.MappedByteBuffer;

import java.nio.channels.FileChannel;

import java.nio.channels.FileChannel.MapMode;

import java.nio.file.Paths;

import java.nio.file.StandardOpenOption;

//使用直接缓冲区完成文件的复制（内存映射文件）

public class NIOBufferDemo2 {

    public static void main(String[] args) throws Exception {

        //直接缓冲区

        FileChannel inChannel = FileChannel.open(Paths.get("F:\\cppdy\\1.jpg"), StandardOpenOption.READ);

        FileChannel outChannel = FileChannel.open(Paths.get("F:\\cppdy\\2.jpg"), StandardOpenOption.READ,StandardOpenOption.WRITE,StandardOpenOption.CREATE);

        //缓冲区

        MappedByteBuffer inMap = inChannel.map(MapMode.READ_ONLY, 0, inChannel.size());

        MappedByteBuffer outMap = outChannel.map(MapMode.READ_WRITE, 0, inChannel.size());

        //直接对缓冲区进行数据读写操作

        byte[] bytes=new byte[inMap.limit()];

        inMap.get(bytes);

        outMap.put(bytes);

        outMap.clear();

        System.out.println("复制完毕");

    }

}