java计算时间段内有多少个月

  public static void main(String[] args) throws ParseException {
            Calendar c1 = Calendar.getInstance();//实例化
            Calendar c2 = Calendar.getInstance();
        SimpleDateFormat sdf=new SimpleDateFormat("yyyyMM");
        String s = "202103";
        String s2 = "202010";
        Date date1 = sdf.parse(s);
        Date date2 = sdf.parse(s2);


            c1.setTime(date1);//设置传入的日期
            c2.setTime(date2);
            int year1 = c1.get(Calendar.YEAR);//获取年
            int year2 = c2.get(Calendar.YEAR);
            int month1 = c1.get(Calendar.MONTH);//月份
            int month2 = c2.get(Calendar.MONTH);
            int day1 = c1.get(Calendar.DAY_OF_MONTH);//日
            int day2 = c2.get(Calendar.DAY_OF_MONTH);
            // 获取年的差值
            int yearInterval = year1 - year2;
            // 如果 d1的 月-日 小于 d2的 月-日 那么 yearInterval-- 这样就得到了相差的年数
            if (month1 < month2 || month1 == month2 && day1 < day2)
                yearInterval--;
            // 获取月数差值
            int monthInterval = (month1 + 12) - month2;
            if (day1 < day2)
                monthInterval--;
            monthInterval %= 12;
            int monthsDiff = Math.abs(yearInterval * 12 + monthInterval);
        System.out.printf(String.valueOf(monthsDiff));

    }