java - 如何在日历上设置某些日子。DAY_OF_WEEK

Question

我需要在方法集中设置一些天。我尝试使用:

c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
c.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY);

但这种方式只设置在星期三。

谢谢你，对我的英语感到抱歉:)

Answer 1

Calendar不按您的预期运行。来自 JavaDoc:

The Calendar class is an abstract class that provides methods for converting between a specific instant in time and a set of calendar fields such as YEAR, MONTH, DAY_OF_MONTH, HOUR, and so on, and for manipulating the calendar fields, such as getting the date of the next week. An instant in time can be represented by a millisecond value that is an offset from the Epoch, January 1, 1970 00:00:00.000 GMT (Gregorian).

请注意，文档指出 specific instant in time 。这意味着 Calendar只能基于纪元中的一个时间点。

当您使用set时您正在调整specific instant in time的方法通过每次通话。因此，首先将其设置为星期一，然后是星期三。

您可以使用List<Calendar>存储多个Calendar实例设置为您所需的天数。

public class CalendarTest {
    public static void main(String[] args) {
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();
        cal1.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
        cal2.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY);

        List<Calendar> calendars = Arrays.asList(cal1, cal2);
    }
}