//获取相隔天数
  /**get the days of the gap of the tow date
 * @param beforedate
 * @param afterdate
 * @return
 * @throws ParseException
 */
static public long getDistinceDay(String beforedate, String afterdate) throws ParseException {
      SimpleDateFormat d = new SimpleDateFormat("yyyy-MM-dd");
      long dayCount=0;
     try{
         java.util.Date d1 = d.parse(beforedate);
         java.util.Date d2 = d.parse(afterdate);

         dayCount = (d2.getTime()-d1.getTime())/(24*60*60*1000);

     }catch(ParseException e){
         System.out.println("Date parse error!");
     }
     return dayCount;
  }
//该片段来自于http://yuncode.net