package com.io.channel;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.CharBuffer;

import java.nio.MappedByteBuffer;

import java.nio.channels.FileChannel;

import java.nio.charset.Charset;

import java.nio.charset.CharsetDecoder;

public class ChannelB {

    public static void main(String[] args) {

        String path = "E:\\fitnesse\\workspace\\javaio\\resource\\";

        String nameFilePath = path + "name.txt";

        String copyFilePath = path + "copy.txt";

        File nf = new File(nameFilePath);

        File cf = new File(copyFilePath);

        //第一步获取Channel，有很多种Channl，这里使用到的是FileChannel

        try(FileChannel inChannel = new FileInputStream(nf).getChannel();

            FileChannel outChannel = new FileOutputStream(cf).getChannel())

        {

            //从name.txt中读取内容到buffer中

            MappedByteBuffer buffer = inChannel.map(FileChannel.MapMode.READ_ONLY , 0 , nf.length());

            //将从name.txt中读取的内容写入到copy.txt

            outChannel.write(buffer);

            buffer.clear();

            //设置编码和解码器

            Charset charset = Charset.forName("GBK");

            CharsetDecoder decoder = charset.newDecoder();

            CharBuffer charBuffer =  decoder.decode(buffer);

            System.out.println(charBuffer);

                } catch (FileNotFoundException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                } catch (IOException e1) {

                    // TODO Auto-generated catch block

                    e1.printStackTrace();

                }

    }

}

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