java中有哪些时间API?

1、Clock类可用于访问当前日期和时间。Clock可以获得当前时区，而不是System.currenttimeMillis()。

Clock clock = Clock.systemDefaultZone();long millis = clock.millis();
 
Instant instant = clock.instant();
Date legacyDate = Date.from(instant);   // legacy java.util.Date

System.out.println(ZoneId.getAvailableZoneIds());// prints all available timezone ids
 
ZoneId zone1 = ZoneId.of("Europe/Berlin");
ZoneId zone2 = ZoneId.of("Brazil/East");
System.out.println(zone1.getRules());
System.out.println(zone2.getRules());
 
// ZoneRules[currentStandardOffset=+01:00]
// ZoneRules[currentStandardOffset=-03:00]

LocalTime now1 = LocalTime.now(zone1);
LocalTime now2 = LocalTime.now(zone2);
 
System.out.println(now1.isBefore(now2));  // false
 
long hoursBetween = ChronoUnit.HOURS.between(now1, now2);
long minutesBetween = ChronoUnit.MINUTES.between(now1, now2);
 
System.out.println(hoursBetween);       // -3
System.out.println(minutesBetween);     // -239