Question

在我的应用中，我想显示用户在本周的约会列表。要传递给API的参数是fromDate和toDate，以毫秒（long）为单位。我需要知道如何获得一周中最后一天的毫秒数（考虑周从星期日开始到周六结束）。

Answer 1

   // get today and clear time of day
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.HOUR_OF_DAY, 0); // ! clear would not reset the hour of day !
        cal.clear(Calendar.MINUTE);
        cal.clear(Calendar.SECOND);
        cal.clear(Calendar.MILLISECOND);

// get start of this week in milliseconds
        cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
        System.out.println("Start of this week:       " + cal.getTime());
        System.out.println("... in milliseconds:      " + cal.getTimeInMillis());

// start of the next week
        cal.add(Calendar.WEEK_OF_YEAR, 1);
        System.out.println("Start of the next week:   " + cal.getTime());
        System.out.println("... in milliseconds:      " + cal.getTimeInMillis());

一周的最后一天加6！

Answer 2

这可以通过将星期几作为星期日添加，然后再添加6天来实现。

// Get current time. You can reset hours/ minutes/ seconds it with default values which you want. 
Calendar c = new GregorianCalendar(Locale.getDefault());

// Set first day of week
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);       
// Add 6 into that to get Saurday
c.add(Calendar.DAY_OF_WEEK, 6);

// Get millisenconds for Saturday
long millies = c.getTimeInMillis();

Answer 3

请检查以下代码，以毫秒为单位获取即将到来的星期六。

public class NextSaturdayMain
{
    public static void main(String[] args) 
    {
        System.out.println(getSaturday(new Date()));
    }

    public static long getSaturday(Date today) 
    {
        Calendar cal = Calendar.getInstance();

        cal.setTime(today);

        int dow = cal.get(Calendar.DAY_OF_WEEK);

        while (dow != Calendar.SATURDAY) {
            int date = cal.get(Calendar.DATE);

            int month = cal.get(Calendar.MONTH);

            int year = cal.get(Calendar.YEAR);

            if (date == getMonthLastDate(month, year)) {

                if (month == Calendar.DECEMBER) {
                    month = Calendar.JANUARY;

                    cal.set(Calendar.YEAR, year + 1);
                } else {
                    month++;
                }

                cal.set(Calendar.MONTH, month);

                date = 1;
            } else {
                date++;
            }

            cal.set(Calendar.DATE, date);

            dow = cal.get(Calendar.DAY_OF_WEEK);
        }
        System.out.println(cal.getTime());
        return cal.getTimeInMillis();
    }

    private static int getMonthLastDate(int month, int year)
    {
        switch (month)
        {
            case Calendar.JANUARY:
            case Calendar.MARCH:
            case Calendar.MAY:
            case Calendar.JULY:
            case Calendar.AUGUST:
            case Calendar.OCTOBER:
            case Calendar.DECEMBER:
                return 31;

            case Calendar.APRIL:
            case Calendar.JUNE:
            case Calendar.SEPTEMBER:
            case Calendar.NOVEMBER:
                return 30;

            default:    //  Calendar.FEBRUARY
                return year % 4 == 0 ? 29 : 28;
        }
    }
}

即将到来的星期六，以毫秒（长）为单位获取日期

3 个答案: