从文件1中读取数据，修改数据的内容，然后存入文件2中，再从文件2中把数据读取出来显示在屏幕上

import java.io.*;
import java.util.Scanner;
public class Test_8_2 {
    public static void main(String[] args) throws IOException {
        String str = "src/allTest/Test_8_2File_1";
        String strs = "src/allTest/Test_8_2File_2";
        File fi = new File(str);
        File fis = new File(strs);
        Scanner sc = new Scanner(System.in);
        BufferedReader br = new BufferedReader(new FileReader(fi));
        String l;
        System.out.println("Test_8_2File_1文件数据：");
        while((l = br.readLine())!= null){
           System.out.println(l);
        }
        System.out.println("请修改您的数据：");
        String strplus = sc.next();
        System.out.println("正在写入您的数据到Test_8_2File_2文件~");
        System.out.println("写入成功，正在读取Test_8_2File_2的数据:");
        BufferedWriter brs = new BufferedWriter(new FileWriter(fis));
        brs.write(strplus);
        brs.flush();
        brs.close();
        BufferedReader brr = new BufferedReader(new FileReader(strs));
        String line;
        while((line = brr.readLine()) != null){
            System.out.println(line);
        }
        System.out.println("读取成功~操作结束~");
        brr.close();
    }
}