使用java 如何实现一个文件夹拷贝功能

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


public class CopyFile {

  public static void copy(String sourceFile , String targetFile) throws Exception{
    FileInputStream in = null;
    FileOutputStream out = null;
    try{
      in = new FileInputStream(new File(sourceFile));
      out = new FileOutputStream(new File(targetFile));
      int c;
      while ((c = in.read()) != -1 ){
        out.write(c);
      }
    }
    finally{
      if (in != null){
        in.close();
      }
      if(out != null){
        out.close();
      }
    }
  }

  public static void main(String[] agrs) throws Exception{
    String filedir = "./tupu0";
    String targetDir = "./MovieList/";
    File directory = new File(filedir);
    File[] fileList = directory.listFiles();
    for(int i=0; i<fileList.length; i++){
      String sourceFile = "./tupu0/" + fileList[i].getName() + "/" + fileList[i].getName() +".txt";
      String targetFile = targetDir + fileList[i].getName();
      System.out.println(fileList[i].getName());
      copy(sourceFile, targetFile);
    }
  }
}