Question

使用Calendar我可以获得当天的周，年和所有详细信息。如何导航到该周的特定日期？

说，calendar.get(Calendar.DAY_OF_WEEK);返回3，表示星期二。现在，我想在那个星期的星期五或那个星期的任何其他日子说。我怎么能这样做？

感谢您的回复。我想我需要让场景更清晰。基本上，我试图在指定的时间段内禁用系统中的电子邮件警报。我得到的价值如下： disableStart =“FRIDAY-19：00” disableEnd =“SUNDAY-19：00”

现在，我需要验证是否应该在特定时间发送电子邮件。例如如果今天=星期四任何时候，发送电子邮件但是，如果今天=星期六，任何时间都不能按照上述值发送。

Answer 1

如果我理解正确，您可以使用Calendar.set（字段，值）方法。

SimpleDateFormat f = new SimpleDateFormat("dd-MM-yyyy");
Calendar c = Calendar.getInstance();
System.out.println(c.get(Calendar.DAY_OF_WEEK));
System.out.println(f.format(c.getTime()));
c.set(Calendar.DAY_OF_WEEK, Calendar.TUESDAY);
System.out.println(c.get(Calendar.DAY_OF_WEEK));
System.out.println(f.format(c.getTime()));

生成输出

Answer 2

Calendar c = Calendar.getInstance();
Date date = new Date();
c.setTime(date);
System.out.println("Today:  " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
System.out.println("MONDAY: " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.TUESDAY);
System.out.println("TUESDAY: " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY);
System.out.println("WEDNESDAY: " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.THURSDAY);
System.out.println("THURSDAY: " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);
System.out.println("FRIDAY: " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);
System.out.println("SATURDAY: " + c.getTime());
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
System.out.println("SUNDAY: " + c.getTime());

给出：

Today:  Fri Oct 08 15:45:14 CEST 2010
MONDAY: Mon Oct 04 15:45:14 CEST 2010
TUESDAY: Tue Oct 05 15:45:14 CEST 2010
WEDNESDAY: Wed Oct 06 15:45:14 CEST 2010
THURSDAY: Thu Oct 07 15:45:14 CEST 2010
FRIDAY: Fri Oct 08 15:45:14 CEST 2010
SATURDAY: Sat Oct 09 15:45:14 CEST 2010
SUNDAY: Sun Oct 10 15:45:14 CEST 2010

哪种接缝意味着，至少在我的系统上，星期几是星期几。

Answer 3

cal.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);

Answer 4

感谢Kevin和Maurice的回答。他们真的给了我起点。

我以此测试代码结束，万一它可以帮助任何人。

private static Date getTimeForAnyDayInWeek(int nDay, int nHour, int nMin)
{
    Calendar c = Calendar.getInstance();
    c.setFirstDayOfWeek(Calendar.MONDAY);
    Date date = Calendar.getInstance().getTime();
    c.setTime(date);
    c.set(Calendar.DAY_OF_WEEK, nDay);
    c.set(Calendar.HOUR_OF_DAY, nHour);
    c.set(Calendar.MINUTE, nMin);
    return c.getTime();
}

public static void main(String[] args)
{
    Date start = getTimeForAnyDayInWeek(6, 19, 00);
    Date end = getTimeForAnyDayInWeek(8, 19, 00);
    Date c = new Date();

    if (start.before(c) && c.before(end))
        System.out.println("BLOCK");
    else
        System.out.println("SEND");
}

谢谢， Anubhav

Answer 5

这是jodatime如此优秀的完美示例，这是我的类似代码

  DateTime dt = new DateTime(); //current datetime, jodatime format
  DateTime fridayLastWeek = dt.minusWeeks(1).dayOfWeek().setCopy("Friday");
  Date convertedtorubbishdateformat = fridayLastWeek.toDate();

我过去常常浪费他的标准日期/日历。然后我得到了jodatime，你不会后悔，它显然将来会被用作标准java的一部分。我没有这么做，打扰了罐子多年，我希望我做了，你不会后悔的。

Java：从Calendar中获取一周中的任何一天

5 个答案: