java批量修改文件名字

package com.test;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class RenameFiles { 
	public final String RDR ="[RDR]";
	public final String ACD ="[ACD]";
    public void ChangeFileName(File file){
	 String dirPath = file.getAbsolutePath();//目录路径
	 Calendar calendar = Calendar.getInstance();
     Date date = calendar.getTime();
     SimpleDateFormat df=new SimpleDateFormat("MMdd");
     String style = df.format(date);
	 if(file.isDirectory()){	
		   File[] files =file.listFiles();
		   for(File f: files){
			   String originalName = f.getName();
			   String toFileName = dirPath+"\\"+style + RDR +originalName;
			   File finalName = new File(toFileName);
			   f.renameTo(finalName);
		   }
	   }
     }

	public static void main(String[] args) { 
        File file = new File("E:\\1");
        new RenameFiles().ChangeFileName(file);

	 } 

	}