java获取几天后的时间，区分周末和不区分

public class DateTest {

    public static void main(String[] args) {
        //当前时间是2021年11月19号，周五
        Date date = new Date();
        //获取两天后的不包含周末的日期，23号
        System.out.println(getAfterDayWithoutWeekend(date, 2));
        //获取两天后的时间，21号
        System.out.println(getAfterDay(date, 2));
    }
    /**
     * 获取几天后的数据，不包含周末
     * 通过calendar获取当前时间的在一周的天数
     * 周日是第一天，周一是第二天...周六是第七天
     * @param date
     * @param diff
     * @return
     */
    private static Date getAfterDayWithoutWeekend(Date date, int diff) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date == null ? new Date() : date);
        calendar.add(Calendar.DATE, diff);
        int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == 1 || dayOfWeek == 7) {
            calendar.add(Calendar.DATE, 2);
        }
        return calendar.getTime();
    }

    private static Date getAfterDay(Date date, int diff) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date == null ? new Date() : date);
        calendar.add(Calendar.DATE, diff);
        return calendar.getTime();
    }
}