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
在某些地区使用毫秒方法可能会导致问题。
举个例子,03/24/2007和03/25/2007之间的差应该是1天;
然而,如果使用毫秒路径,你将得到0天,如果你在英国运行这个!
/** Manual Method - YIELDS INCORRECT RESULTS - DO NOT USE**/
/* This method is used to find the no of days between the given dates */
public long calculateDays(Date dateEarly, Date dateLater) {
return (dateLater.getTime() - dateEarly.getTime()) / (24 * 60 * 60 * 1000);
}
更好的实现方法是使用java.util.Calendar
/** Using Calendar - THE CORRECT WAY**/
public static long daysBetween(Calendar startDate, Calendar endDate) {
Calendar date = (Calendar) startDate.clone();
long daysBetween = 0;
while (date.before(endDate)) {
date.add(Calendar.DAY_OF_MONTH, 1);
daysBetween++;
}
return daysBetween;
}
其他回答
看看Joda Time,它是一个改进的Java日期/时间API,应该可以很好地与Scala一起工作。
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。
int daysDiff = (date1.getTime() - date2.getTime()) / MILLIS_PER_DAY;
另一个纯Java变体:
public boolean isWithin30Days(Calendar queryCalendar) {
// 1. Take the date you are checking, and roll it back N days
Calendar queryCalMinus30Days = Calendar.getInstance();
queryCalMinus30Days.setTime(queryCalendar.getTime());
queryCalMinus30Days.add(Calendar.DATE, -30); // subtract 30 days from the calendar
// 2. Get respective milliseconds for the two Calendars: now & queryCal minus N days
long nowL = Calendar.getInstance().getTimeInMillis();
long queryCalMinus30DaysL = queryCalMinus30Days.getTimeInMillis();
// 3. if nowL is still less than the queryCalMinus30DaysL, it means queryCalendar is more than 30 days into future
boolean isWithin30Days = nowL >= queryCalMinus30DaysL;
return isWithin30Days;
}
感谢这里的入门代码:https://stackoverflow.com/a/30207726/2162226
您可以尝试较早版本的Java。
public static String daysBetween(Date createdDate, Date expiryDate) {
Calendar createdDateCal = Calendar.getInstance();
createdDateCal.clear();
createdDateCal.setTime(createdDate);
Calendar expiryDateCal = Calendar.getInstance();
expiryDateCal.clear();
expiryDateCal.setTime(expiryDate);
long daysBetween = 0;
while (createdDateCal.before(expiryDateCal)) {
createdDateCal.add(Calendar.DAY_OF_MONTH, 1);
daysBetween++;
}
return daysBetween+"";
}