问题：有一个名字叫123.txt的文本文件，里面存放了1一句话“我喜欢编程：123”，将这个文件复制一份并最终将复制后的结果(fz.txt)存放在D盘的cms文件夹下

package com.sj.zy;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class Zy02 {
    private static String nu11;
    public static void main(String[] args) throws IOException {
        BufferedReader br =new BufferedReader(new FileReader("d:/123.txt"));
        File file=new File("D:/cms");
        if(!file.isDirectory()) {
            file.mkdir();
        }
        BufferedWriter bw =new BufferedWriter (new FileWriter("D:/cms/fz.txt"));
        String line= nu11;
        while((line = br.readLine())!=nu11) {
            bw.write(line);
        }
        bw.close();
        br.close();

    }

}