得到两个日期之间的间隔天数

     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;

    }