文件上传时生成“日期+随机数”式文件名前缀的Java代码

]package cn.edu.hbcit.ips.bean;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;
import org.apache.log4j.Logger;
/**
* <p>Description: 文件操作</p>
*
* <p>Copyright: Copyright (c) 2009</p>
*
* <p>Company: 河北工业职业技术学院</p>
*
* @author 作者 : liwei5946@gmail.com
* @version 创建时间：Feb 6, 2009 5:10:48 PM
*/
public class FileOperate {
protected final Logger log = Logger.getLogger(FileOperate.class.getName());
public FileOperate() {
// TODO Auto-generated constructor stub
}
/*
* 生成随机文件名
*/
public String generateRandomFilename(){
String RandomFilename = "";
Random rand = new Random();//生成随机数
int random = rand.nextInt();

Calendar calCurrent = Calendar.getInstance();
int intDay = calCurrent.get(Calendar.DATE);
int intMonth = calCurrent.get(Calendar.MONTH) + 1;
int intYear = calCurrent.get(Calendar.YEAR);
String now = String.valueOf(intYear) + "_" + String.valueOf(intMonth) + "_" +
String.valueOf(intDay) + "_";
log.debug("生成于今日的文件名前缀为："+now);

RandomFilename = now + String.valueOf(random > 0 ? random : ( -1) * random) + ".";

return RandomFilename;
}
}