[黑手]获取2个时间段之间相差的日历上对应的时间天数

public long getDifferenceDate(String startDate) {
        Calendar calendar = Calendar.getInstance();
        //初始化日历时间
        calendar.setTime(new Date(System.currentTimeMillis()));
        String year = String.valueOf(calendar.get(Calendar.YEAR));
        String month = String.valueOf(calendar.get(Calendar.MONTH) + 1);
        String date = String.valueOf(calendar.get(Calendar.DAY_OF_MONTH));
        String day = String.valueOf(calendar.get(Calendar.DAY_OF_WEEK) - 1);
        int hour = calendar.get(Calendar.HOUR_OF_DAY);
        int minute = calendar.get(Calendar.MINUTE);
        int second = calendar.get(Calendar.SECOND);
        //当前时间  yyyy-mm-dd
        String endDate = new Date(System.currentTimeMillis()).toString();
        String[] endDates = endDate.split("-");
        String[] split = startDate.split(" ");
        String[] startDates = split[0].split("-");
        //实际月份-1得到日历月份  比如：2021-1-22 换算日历：2021-0-22
        calendar.set(Integer.parseInt(startDates[0]), Integer.parseInt(startDates[1]) - 1, Integer.parseInt(startDates[2]));
        // 返回当前时间，作为从开始时间的 UTC 毫秒值。
        long startTime = calendar.getTimeInMillis();
        calendar.set(Integer.parseInt(endDates[0]), Integer.parseInt(endDates[1]) - 1, Integer.parseInt(endDates[2]));
        long endTime = calendar.getTimeInMillis();
        long interdays = (endTime - startTime) / (1000 * 60 * 60 * 24);
        return interdays;
    }