java如何实现两个时间相减得到年月

public static void main(String[] args) {
        String startTime = "2015-06-20";
        String endTime = "2016-02-05";

        String[] arg1 = startTime.split("-");
        String[] arg2 = endTime.split("-");
        int year1 = Integer.valueOf(arg1[0]);
        int year2 = Integer.valueOf(arg2[0]);
        int month1 = Integer.valueOf(arg1[1]);
        int month2 = Integer.valueOf(arg2[1]);
        int day1 = Integer.valueOf(arg1[2]);
        int day2 = Integer.valueOf(arg2[2]);
        int md = 0 ;
        if(year1!=year2){
            md = day2>day1?0:-1;
        }
        int diffMonth = (year2*12+month2)-(year1*12+month1)+md;
        int yearNum = diffMonth/12;
        int monthNum = diffMonth % 12;
        System.out.println("年数="+yearNum+",月数="+monthNum);
    }