Java实现求两个日期之间相差的天数

最新推荐文章于 2022-07-01 10:00:57 发布

LLEGAIN

最新推荐文章于 2022-07-01 10:00:57 发布

阅读量669

点赞数

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/Love_Legain/article/details/79015261

本文介绍如何使用Java编程计算两个日期之间的天数差。通过Java 8的日期时间API，我们可以方便地进行日期操作，包括获取两个日期相减得到的天数。详细步骤和示例代码将帮助你理解这一过程。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

public class DateUtils {

    public static void main(String[] args) throws ParseException {
        System.out.println(differentDays("2018-01-01", "2017-01-01"));
    }


    /**
     * @param dateStr1
     * @param dateStr2
     * @return date1和date2相差的天数，如果date1>date2为正数，否则为负数或零。
     * @throws ParseException
     */
    public static int differentDays(String dateStr1, String dateStr2) throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();
        cal1.setTime(sdf.parse(dateStr1));
        cal2.setTime(sdf.parse(dateStr2));

        int difference = 0;
        int minus = -1;
        if(cal1.after(cal2)){
            minus = 1;
            Calendar temp = cal1;
            cal1 = cal2;
            cal2 = temp;
        }

        int day1 = cal1.get(Calendar.DAY_OF_YEAR);
        int day2 = cal2.get(Calendar.DAY_OF_YEAR);
        int year1 = cal1.get(Calendar.YEAR);
        int year2 = cal2.get(Calendar.YEAR);

        if (year1 != year2) {
            int timeDistance = 0;
            for (int i = year1; i < year2; i++) {
                if ((i % 4 == 0 && i % 100 != 0) || (i % 400 == 0)) {
                    timeDistance += 366;
                } else {
                    timeDistance += 365;
                }
            }
            difference = timeDistance + (day2 - day1);
        } else {
            difference = day2 - day1;
        }
        return difference * minus;
    }

}