随机选择日期段(java)

package com.lrs.hibernate;

import java.text.SimpleDateFormat;
import java.util.Date;

public class RandomDate {
	
	/**
	 * 获取随机日期
	 * @param beginDate 起始日期, 格式为: yyyy-MM-dd
	 * @param endDate 结束日期,格式为: yyyy-MM-dd
	 * @return
	 */
	public Date randomDate(String beginDate, String endDate) {
		try {
			SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd");
			Date start = format.parse(beginDate);
			Date end = format.parse(endDate);
			
			if (start.getTime() >= end.getTime()) {
				return null;
			}
			
			long date = random(start.getTime(), end.getTime());
			
			return new Date(date);
		} catch(Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	
	private static long random (long begin, long end) {
		long rtn = begin + (long)(Math.random() * (end - begin));
		if (rtn == begin || rtn == end) {
			return random(begin,end);
		}
		return rtn;
	}
}