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
下面的代码可以给你想要的输出:
String startDate = "Jan 01 2015";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MMM dd yyyy");
LocalDate date = LocalDate.parse(startDate, formatter);
String currentDate = "Feb 11 2015";
LocalDate date1 = LocalDate.parse(currentDate, formatter);
System.out.println(date1.toEpochDay() - date.toEpochDay());
其他回答
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));
只需在两个Date对象上使用下面的方法。如果你想传递当前日期,只需传递new date()作为第二个参数,因为它是用当前时间初始化的。
public String getDateDiffString(Date dateOne, Date dateTwo)
{
long timeOne = dateOne.getTime();
long timeTwo = dateTwo.getTime();
long oneDay = 1000 * 60 * 60 * 24;
long delta = (timeTwo - timeOne) / oneDay;
if (delta > 0) {
return "dateTwo is " + delta + " days after dateOne";
}
else {
delta *= -1;
return "dateTwo is " + delta + " days before dateOne";
}
}
此外,除了从天数,如果,你也想要其他参数的差异,使用下面的片段,
int year = delta / 365;
int rest = delta % 365;
int month = rest / 30;
rest = rest % 30;
int weeks = rest / 7;
int days = rest % 7;
p.s. Code完全取自SO答案。
如果你想修复跨越夏时制边界的日期范围的问题(例如,一个日期在夏季,另一个日期在冬季),你可以使用这个来获得天数的差异:
public static long calculateDifferenceInDays(Date start, Date end, Locale locale) {
Calendar cal = Calendar.getInstance(locale);
cal.setTime(start);
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
long startTime = cal.getTimeInMillis();
cal.setTime(end);
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
long endTime = cal.getTimeInMillis();
// calculate the offset if one of the dates is in summer time and the other one in winter time
TimeZone timezone = cal.getTimeZone();
int offsetStart = timezone.getOffset(startTime);
int offsetEnd = timezone.getOffset(endTime);
int offset = offsetEnd - offsetStart;
return TimeUnit.MILLISECONDS.toDays(endTime - startTime + offset);
}
如果你用d1和d2作为日期,最好的解决方案可能是这样的:
int days1 = d1.getTime()/(60*60*24*1000);//find the number of days since the epoch.
int days2 = d2.getTime()/(60*60*24*1000);
然后说
days2-days1
或者其他
Since dates can contain hours and minutes, final result will be rounded down, which will result in incorrect value. For example, you calculate difference between today at 22:00 p.m and day after tomorrow 00:00 a.m, so the final result will be 1, because in reality it was 1.08 or smth difference, then it gets rounded down when calling TimeUnit.MILLISECONDS.toDays(..). That's why you need to take that in account, so in my solution I subtract the remainder of milliseconds from milliseconds in a day. Additionally, if you want to count the end date, you need to +1 it.
import java.util.Date;
import java.util.concurrent.TimeUnit;
public static long getDaysBetween(Date date1, Date date2, boolean includeEndDate) {
long millisInDay = 60 * 60 * 24 * 1000;
long difference = Math.abs(date1.getTime() - date2.getTime());
long add = millisInDay - (difference % millisInDay);//is used to calculate true number of days, because by default hours, minutes are also counted
return TimeUnit.MILLISECONDS.toDays(difference + add) + (includeEndDate ? 1 : 0);
}
测试:
Date date1 = new Date(121, Calendar.NOVEMBER, 27); //2021 Nov 27
Date date2 = new Date(121, Calendar.DECEMBER, 29); //2021 Dec 29
System.out.println( getDaysBetween(date1, date2, false) ); //32 days difference
System.out.println( getDaysBetween(date1, date2, true) ); //33 days difference