【转】java求两个日期的天数差

转自http://hi.baidu.com/dashu1021/item/6c4be20915c700dadde5b089

public static int getDaysBetween (String beginDate, String endDate) throws ParseException
    {
         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
         Date bDate = format.parse(beginDate);
         Date eDate = format.parse(endDate);
         Calendar d1 = new GregorianCalendar();
         d1.setTime(bDate);
         Calendar d2 = new GregorianCalendar();
        d2.setTime(eDate);
        int days = d2.get(Calendar.DAY_OF_YEAR) - d1.get(Calendar.DAY_OF_YEAR);
        int y2 = d2.get(Calendar.YEAR);
        if (d1.get(Calendar.YEAR) != y2)
        {
               d1 = (Calendar) d1.clone();
              do   {
                          days += d1.getActualMaximum(Calendar.DAY_OF_YEAR);//得到当年的实际天数
                         d1.add(Calendar.YEAR, 1);
            }    while (d1.get(Calendar.YEAR) != y2);
       }
        return days;
   }