java Calendar

1. 求两个时间相差月份

SimpleDateFormat yyyyMM = new SimpleDateFormat("yyyyMM");        Calendar cal1 = Calendar.getInstance();        cal1.setTime(yyyyMM.parse(startTime));        Calendar cal2 = Calendar.getInstance();        cal2.setTime(yyyyMM.parse(endTime));        return  (cal2.get(Calendar.YEAR) - cal1                .get(Calendar.YEAR))* 12+ cal2.get(Calendar.MONTH)                - cal1.get(Calendar.MONTH);