输入代码
```package demo;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyDemo {
    public void copy(File file) throws IOException{
        if(file.exists()==false){
            System.out.println("该路径不存在");
        }

       File fi[]=file.listFiles();
       if (fi != null &&fi.length>0 ){
           for (File cfile : fi) {
            if(cfile.isDirectory()){
                copy(cfile);
            }else{
                @SuppressWarnings("resource")
                FileInputStream fis=new FileInputStream(cfile);
                 String     cmd=cfile.getName();
                 @SuppressWarnings("resource")
                FileOutputStream fos=new FileOutputStream("F:\"+cmd);
                 int b=0;
                 byte []  arr=  new byte [1024*2];
                 while (( b=fis.read(arr) )!=-1){
                     fos.write(arr,0,b);
                     fos.flush();
                 }
                 fos.close();
                 fis.close();
            }
        }

       }
    }
    public static void main(String[] args) throws IOException {
          CopyDemo demo=new CopyDemo();
          File file=new File("E:\java");
             demo.copy(file);

    }

}