我在Scala中使用Java的Java .util.Date类,并希望比较Date对象和当前时间。我知道我可以通过使用getTime()来计算delta:
(new java.util.Date()).getTime() - oldDate.getTime()
然而,这只给我留下一个长表示毫秒。有没有更简单,更好的方法来得到时间?
我在Scala中使用Java的Java .util.Date类,并希望比较Date对象和当前时间。我知道我可以通过使用getTime()来计算delta:
(new java.util.Date()).getTime() - oldDate.getTime()
然而,这只给我留下一个长表示毫秒。有没有更简单,更好的方法来得到时间?
当前回答
public static void main(String[] args) {
String dateStart = "01/14/2012 09:29:58";
String dateStop = "01/14/2012 10:31:48";
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date d1 = null;
Date d2 = null;
try {
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);
DateTime date11 = new DateTime(d1);
DateTime date22 = new DateTime(d2);
int days = Days.daysBetween(date11.withTimeAtStartOfDay(), date22.withTimeAtStartOfDay()).getDays();
int hours = Hours.hoursBetween(date11, date22).getHours() % 24;
int minutes = Minutes.minutesBetween(date11, date22).getMinutes() % 60;
int seconds = Seconds.secondsBetween(date11, date22).getSeconds() % 60;
if (hours > 0 || minutes > 0 || seconds > 0) {
days = days + 1;
}
System.out.println(days);
} catch (Exception e) {
e.printStackTrace();
}
}
这将为同一天提供日期差异
其他回答
不使用标准API,不行。你可以这样做:
class Duration {
private final TimeUnit unit;
private final long length;
// ...
}
或者你可以使用Joda:
DateTime a = ..., b = ...;
Duration d = new Duration(a, b);
使用GMT时区获取一个Calendar实例,使用Calendar类的set方法设置时间。GMT时区偏移量为0(并不重要),夏令时标志设置为false。
final Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
cal.set(Calendar.YEAR, 2011);
cal.set(Calendar.MONTH, 9);
cal.set(Calendar.DAY_OF_MONTH, 29);
cal.set(Calendar.HOUR, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
final Date startDate = cal.getTime();
cal.set(Calendar.YEAR, 2011);
cal.set(Calendar.MONTH, 12);
cal.set(Calendar.DAY_OF_MONTH, 21);
cal.set(Calendar.HOUR, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
final Date endDate = cal.getTime();
System.out.println((endDate.getTime() - startDate.getTime()) % (1000l * 60l * 60l * 24l));
先回答最初的问题:
将以下代码放入Long getAge(){}这样的函数中
Date dahora = new Date();
long MillisToYearsByDiv = 1000l *60l * 60l * 24l * 365l;
long javaOffsetInMillis = 1990l * MillisToYearsByDiv;
long realNowInMillis = dahora.getTime() + javaOffsetInMillis;
long realBirthDayInMillis = this.getFechaNac().getTime() + javaOffsetInMillis;
long ageInMillis = realNowInMillis - realBirthDayInMillis;
return ageInMillis / MillisToYearsByDiv;
这里最重要的是在乘法和除法时处理长数字。当然,还有Java在日期演算中应用的偏移量。
:)
以下是一种解决方案,因为我们有许多方法可以实现这一点:
import java.util.*;
int syear = 2000;
int eyear = 2000;
int smonth = 2;//Feb
int emonth = 3;//Mar
int sday = 27;
int eday = 1;
Date startDate = new Date(syear-1900,smonth-1,sday);
Date endDate = new Date(eyear-1900,emonth-1,eday);
int difInDays = (int) ((endDate.getTime() - startDate.getTime())/(1000*60*60*24));
简单的diff(不含lib)
/**
* Get a diff between two dates
* @param date1 the oldest date
* @param date2 the newest date
* @param timeUnit the unit in which you want the diff
* @return the diff value, in the provided unit
*/
public static long getDateDiff(Date date1, Date date2, TimeUnit timeUnit) {
long diffInMillies = date2.getTime() - date1.getTime();
return timeUnit.convert(diffInMillies,TimeUnit.MILLISECONDS);
}
然后你可以调用:
getDateDiff(date1,date2,TimeUnit.MINUTES);
以分钟为单位获取两个日期的差值。
TimeUnit是java.util.concurrent。TimeUnit,一个从纳米到天的标准Java枚举。
人类可读的差异(不含lib)
public static Map<TimeUnit,Long> computeDiff(Date date1, Date date2) {
long diffInMillies = date2.getTime() - date1.getTime();
//create the list
List<TimeUnit> units = new ArrayList<TimeUnit>(EnumSet.allOf(TimeUnit.class));
Collections.reverse(units);
//create the result map of TimeUnit and difference
Map<TimeUnit,Long> result = new LinkedHashMap<TimeUnit,Long>();
long milliesRest = diffInMillies;
for ( TimeUnit unit : units ) {
//calculate difference in millisecond
long diff = unit.convert(milliesRest,TimeUnit.MILLISECONDS);
long diffInMilliesForUnit = unit.toMillis(diff);
milliesRest = milliesRest - diffInMilliesForUnit;
//put the result in the map
result.put(unit,diff);
}
return result;
}
http://ideone.com/5dXeu6
输出类似Map:{DAYS=1, HOURS=3, MINUTES=46, SECONDS=40, MILLISECONDS=0, MICROSECONDS=0, NANOSECONDS=0},单位是有序的。
您只需将该映射转换为用户友好的字符串。
警告
上面的代码段计算两个瞬间之间的简单差。它会在夏令时切换期间导致问题,就像这篇文章中解释的那样。这意味着如果你计算没有时间的日期之间的差异,你可能会少了一天/小时。
在我看来,日期的差异是主观的,尤其是在日子上。你可以:
计算经过24小时的时间:day+1 - day = 1 day = 24h 计算经过的时间,考虑到夏令时:天+1 -天= 1 = 24小时(但使用午夜时间和夏令时,它可以是0天和23小时) 计算日开关的数量,这意味着一天+1 1pm -一天11am = 1天,即使经过的时间只有2h(如果有夏令时则为1h:p)
我的答案是有效的,如果你的日期差异的定义天匹配第一种情况
与JodaTime
如果你正在使用JodaTime,你可以得到2个瞬间的差异(millies支持ReadableInstant)日期:
Interval interval = new Interval(oldInstant, new Instant());
但是你也可以得到本地日期/时间的差异:
// returns 4 because of the leap year of 366 days
new Period(LocalDate.now(), LocalDate.now().plusDays(365*5), PeriodType.years()).getYears()
// this time it returns 5
new Period(LocalDate.now(), LocalDate.now().plusDays(365*5+1), PeriodType.years()).getYears()
// And you can also use these static methods
Years.yearsBetween(LocalDate.now(), LocalDate.now().plusDays(365*5)).getYears()