如何从日历中获取日期？

java gregorian-calendar

2022-09-01 17:03:53

我有一个包含一个人的出生日期作为.MapGregorianCalendar

例如：

{
    motherEmailID=null,
    coreType=Ticket,
    _NULL=null,
    additionalFaclitiesProvided=[],
    dateOfBirth=java.util.GregorianCalendar[
        time=585340200000,
        areFieldsSet=false,
        areAllFieldsSet=false,
        lenient=true,
        zone=sun.util.calendar.ZoneInfo[id="GMT",
    offset=0,
    dstSavings=0,
    useDaylight=false,
    transitions=0,
    lastRule=null],
        firstDayOfWeek=1,
        minimalDaysInFirstWeek=1,
        ERA=1,
        YEAR=1988,
        MONTH=6,
        WEEK_OF_YEAR=30,
        WEEK_OF_MONTH=4,
        DAY_OF_MONTH=20,
        DAY_OF_YEAR=202,
        DAY_OF_WEEK=4,
        DAY_OF_WEEK_IN_MONTH=3,
        AM_PM=0,
        HOUR=0,
        HOUR_OF_DAY=0,
        MINUTE=0,
        SECOND=0,
        MILLISECOND=0,
        ZONE_OFFSET=19800000,
        DST_OFFSET=0],
    targetEnd=null,
    year_semester=null
}

我需要一个，但在我的数据库中，它只有格式。数据库中列的数据类型为。如何以某种格式获取出生日期？DateCalendarDateTimeDate

答案 1

Calendar calendar  = ( Calendar )  thatMap.get("dateOfBirth");
Date date = calendar.getTime();

下面是一个可用于测试它的示例，并查看它是否满足了您的需要。

import java.util.*;
import java.text.*;

public class GetDate {
     public static void main( String [] args ) {
        Map map = new HashMap();
        map.put("dateOfBirth", Calendar.getInstance() );
        map.put("additionalFaclitiesProvided", new ArrayList() );
        /// etc. 
        System.out.println( map );

        Calendar cal = ( Calendar ) map.get("dateOfBirth");
        Date date = cal.getTime();
        // Addressing your comment:
        SimpleDateFormat sdf = new SimpleDateFormat("dd.MM.yyyy");
        System.out.println( "The date is: "+  sdf.format( date )  );
    }
}

输出：

java GetDate 
    {dateOfBirth=java.util.GregorianCalendar[
        time=1282824447050,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[
            id="America/Mexico_City",offset=-21600000,dstSavings=3600000,useDaylight=true,transitions=99,lastRule=java.util.SimpleTimeZone[
                id=America/Mexico_City,offset=-21600000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=3,startDay=1,
                startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=2,endMonth=9,endDay=-1,endDayOfWeek=1,endTime=7200000,endTimeMode=0
            ]
        ],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2010,MONTH=7,WEEK_OF_YEAR=35,WEEK_OF_MONTH=4,DAY_OF_MONTH=26,DAY_OF_YEAR=238,DAY_OF_WEEK=5,
            DAY_OF_WEEK_IN_MONTH=4,AM_PM=0,HOUR=7,HOUR_OF_DAY=7,MINUTE=7,SECOND=27,MILLISECOND=50,ZONE_OFFSET=-21600000,DST_OFFSET=3600000]**, additionalFaclitiesProvided=[]
    }

日期是： 26.08.2010

答案 2

从到（或java.sql.Datejava.util.Calendarjava.util.GregorianCalendar)

Calendar cal = new GregorianCalendar();
cal.setTime(date);   // java.sql.Date date;

// then set the GregorianCalendar in your map
map.put('dateOfBirth', cal);

从到java.util.Calendarjava.sql.Date

java.sql.Date date = new java.sql.Date(map.get('dateOfBirth').getTimeInMillis());

** 注意 **

java.sql.Timestamp是的兄弟姐妹，并且两者都扩展，因此您可以以完全相同的方式使用其中任何一个。java.sql.Datejava.util.Date

此外，要将日期字符串转换为日期对象，请使用 SimpleDateFormat ：

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US);
Date d = sdf.parse("2010-08-26 8:34:00");
Calendar cal = Calendar.getInstance();
cal.setTime(d);

并扭转它

String dateStr1 = sdf.format(cal.getTime());
// or
String dateStr2 = sdf.format(date);  // java.sql.Date / java.util.Date