I have receive a timestamp in request as Integer format
target_time = 1728962183
Then I want to use it to compare with LocalDateTime.now() to decide the code flow.
Exp:
if(target_time < LocalDateTime.now()) { // perform some action } How do I convert the Integer timestamp to Date format?
Instant .ofEpochSecond ( 1_728_962_183L ) .isBefore( Instant.now() ) If you know that number to be a count of whole seconds since the epoch reference of first moment of 1970 in UTC (1970-01-01T00:00Z), then convert to an Instant.
Instantlong count = 1_728_962_183L; Instant instant = Instant.ofEpochSecond ( count ); instant.toString() = 2024-10-15T03:16:23Z
Compare to the current moment to see if that moment has passed.
boolean isPast = instant.isBefore( Instant.now() ) ; LocalDateTime is the wrong classYou asked:
compare with LocalDateTime.now(
The LocalDateTime class represents a date with time-of-day, but lacks the context of a time zone or offset-from-UTC. Without that context, a date-with-time is ambiguous. We don't know if that was the date and time in Tokyo Japan, or in Toulouse France, or in Toledo Ohio US – three very different moments, several hours apart.
So the LocalDateTime class cannot represent a moment, is not a point on the timeline. So it makes no sense to compare a LocalDateTime to a moment.
Three classes in java.time represent a moment. They provide three different ways to look at a moment.
InstantOffsetDateTimeZonedDateTimeAn offset is merely a number of hours-minutes-seconds. A time zone is much more. A time zone is a named history of the past, present, and future changes to the offset used by the people of a particular region, as decided by their politicians.
