Java日历添加随机数毫秒？

Question

嗨，我发生了一些奇怪的事情。我只是简单地获取一个日历对象，将其转换为其各个部分，然后将其放回日历中(无论有或没有任何更改。在本例中，我不进行任何更改)。我的意思是，这应该被剪切和粘贴。我还尝试使用 calendar = Calendar.getInstance() 创建日历并手动设置所有内容。 calendar.set(Calendar.YEAR, mStartYear);很快。仍然给出错误的 Calendar 对象。我也尝试过设置毫秒，似乎总是有一些垃圾毫秒..但时间以某种方式完全关闭。也许有人看到了愚蠢的疏忽，但我被难住了。

这也是一个 Android 应用程序，但对于基本的 Java 库对象来说应该不重要。

注意 Weekview 是我正在使用的库之一的数据包装器。它有一个开始和结束日历。

这是调试器在内存中列出的内容..

mEndDay = 19
mEndHour = 9

mEndMinute = 30
mEndMonth = 8
mEndYear = 2015
mSeekAmount = 0
mStartDay = 18
mStartHour = 23
mStartMinute = 0
mStartMonth = 8
mStartYear = 2015


            Calendar calendarStart = Calendar.getInstance();
            calendarStart.set(mStartYear,mStartMonth,mStartDay,mStartHour,mStartMinute);

            Calendar calendarEnd = Calendar.getInstance();
            calendarEnd.set(mEndYear,mEndMonth,mEndDay,mEndHour,mEndMinute);

我最终得到

Start 1442363359161
End 1442363359161

calendarStart = {GregorianCalendar@20968} "java.util.GregorianCalendar[time=?,areFieldsSet=false,lenient=true,zone=America/Denver,firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2015,MONTH=8,WEEK_OF_YEAR=38,WEEK_OF_MONTH=3,DAY_OF_MONTH=18,DAY_OF_YEAR=258,DAY_OF_WEEK=3,DAY_OF_WEEK_IN_MONTH=3,AM_PM=1,HOUR=6,HOUR_OF_DAY=23,MINUTE=0,SECOND=19,MILLISECOND=161,ZONE_OFFSET=-25200000,DST_OFFSET=3600000]"
calendarEnd = {GregorianCalendar@20969} "java.util.GregorianCalendar[time=?,areFieldsSet=false,lenient=true,zone=America/Denver,firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2015,MONTH=8,WEEK_OF_YEAR=38,WEEK_OF_MONTH=3,DAY_OF_MONTH=19,DAY_OF_YEAR=258,DAY_OF_WEEK=3,DAY_OF_WEEK_IN_MONTH=3,AM_PM=1,HOUR=6,HOUR_OF_DAY=9,MINUTE=30,SECOND=19,MILLISECOND=161,ZONE_OFFSET=-25200000,DST_OFFSET=3600000]"

期待

Start 1442638800000
End 1442676600000

mEndTime = {GregorianCalendar@20990} "java.util.GregorianCalendar[time=1442676600000,areFieldsSet=true,lenient=true,zone=America/Denver,firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2015,MONTH=8,WEEK_OF_YEAR=38,WEEK_OF_MONTH=3,DAY_OF_MONTH=19,DAY_OF_YEAR=262,DAY_OF_WEEK=7,DAY_OF_WEEK_IN_MONTH=3,AM_PM=0,HOUR=9,HOUR_OF_DAY=9,MINUTE=30,SECOND=0,MILLISECOND=0,ZONE_OFFSET=-25200000,DST_OFFSET=3600000]"
mName = {String@20991} "sleep"
mStartTime = {GregorianCalendar@20992} "java.util.GregorianCalendar[time=1442638800000,areFieldsSet=true,lenient=true,zone=America/Denver,firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2015,MONTH=8,WEEK_OF_YEAR=38,WEEK_OF_MONTH=3,DAY_OF_MONTH=18,DAY_OF_YEAR=261,DAY_OF_WEEK=6,DAY_OF_WEEK_IN_MONTH=3,AM_PM=1,HOUR=11,HOUR_OF_DAY=23,MINUTE=0,SECOND=0,MILLISECOND=0,ZONE_OFFSET=-25200000,DST_OFFSET=3600000]"

这是我最初设置的地方..

   WeekViewEvent weekViewEvent = dateWrapperParam.getWeekViewEvent();
    Calendar endCalendar = weekViewEvent.getEndTime();
    Calendar startCalendar = weekViewEvent.getStartTime();

    Date endDate = endCalendar.getTime();
    Date startDate = startCalendar.getTime();

    mStartHour = startCalendar.get(Calendar.HOUR_OF_DAY);
    mStartMinute = startCalendar.get(Calendar.MINUTE);
    mStartDay = startCalendar.get(Calendar.DAY_OF_MONTH);
    mStartMonth = startCalendar.get(Calendar.MONTH);
    mStartYear = startCalendar.get(Calendar.YEAR);

    mEndHour = endCalendar.get(Calendar.HOUR_OF_DAY);
    mEndMinute = endCalendar.get(Calendar.MINUTE);
    mEndDay = endCalendar.get(Calendar.DAY_OF_MONTH);
    mEndMonth = endCalendar.get(Calendar.MONTH);
    mEndYear = endCalendar.get(Calendar.YEAR);

Answer 1

在 Calendar.set 的文档中，据说:

Sets the values for the fields YEAR, MONTH, DAY_OF_MONTH, HOUR, MINUTE, and SECOND. Previous values of other fields are retained. If this is not desired, call clear() first.

原因是并非所有字段都使用此方法设置，在您的情况下，您没有设置 MILLISECOND 。因此它保留了实例创建时的值。

Calendar.clear的来电将会

Sets all the calendar field values and the time value (millisecond offset from the Epoch) of this Calendar undefined.

一个简单的例子:

    Calendar c = GregorianCalendar.getInstance();
    c.clear();
    c.set(2019, Calendar.NOVEMBER, 03, 16, 15, 03);

    System.out.println(c.getTime());
    System.out.println(c.getTimeInMillis());

Sun Nov 03 16:15:03 CET 2019
1572794103000

未定义毫秒将给出 0