java 字符流

package com.jack.io;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;


public class main {
    public static void main(String[] args) throws Exception {
        //文件的复制
        long s = System.currentTimeMillis();
        File file1 = new File("D:\test1.txt");
        File file2 = new File("D:\test2.txt");

        char[] cs = new char[1024];
        FileReader fileReader = new FileReader(file1);
        FileWriter fileWriter = new FileWriter(file2, true); //true 后面继续写入，不覆盖
        while (fileReader.read(cs) != -1) {
            fileWriter.write(cs);
        }

        fileReader.close();

        fileWriter.flush();
        fileWriter.close();

        long e = System.currentTimeMillis();
        System.out.println("复制文件，耗时毫秒：" + (e - s));
    }
}