How to get number of days between two java.util.Date variables in scala?-CodePudding

I could not find any hand method on java.util.Date function in order to get number of days between 2 dates?

How should I get number of days?

CodePudding user response：

First, convert your legacy java.util.Date objects to their modern replacements, java.time.Instant. Call new methods added to the old classes.

Instant start = javaUtilDateStart.toInstant() ;

If by “number of days” you mean “number of 24-hour chunks of time”, without regard for calendar, use Duration.

long days = Duration.between( start , end ).toDays() ;

If you meant calendar days, you need to specify the time zone by which you want to perceive dates.

ZoneId z = ZoneId.of( "Asia/Tokyo" ) ;

Apply that zone to Instant to produce a ZonedDateTime. Same moment, same point on the timeline, different wall-clock time and date.

ZonedDateTime startZdt = start.atZone( z ) ;

Calculate elapsed days using ChronoUnit enum DAYS.

long days = ChronoUnit.between( startZdt , endZdt ) ;