In Java 8 Date and Time went another remodeling resulting in much better API and concepts better reflecting developer’s needs. Here we’ll go through Java 8 new Date and Time concepts.
Java Time Clock Tutorial
The java.time.Clock class provides access to the current instant, date and time using a time-zone. These are the main properties of the class:
- Use of the Clock class is optional, because all key date-time classes have a now() factory method that uses the system clock in the default time zone.
- Use Dependency Injection framework to provide Clock implementations.
The class declaration is:
public abstract class Clock
extends Object
Methods inheritance
Objects of this class inherit methods from the following classes:
- java.lang.Object
Methods of java.time.Clock:
- boolean equals(Object obj)
Checks if this clock is equal to another clock. - static Clock fixed(Instant fixedInstant, ZoneId zone)
This method returns a clock that always returns the same time. - abstract ZoneId getZone()
Gets the time-zone being used to create dates and times. - int hashCode()
A hash code for this clock. - abstract Instant instant()
Gets the current instant of the clock. - long millis()
Gets the current millisecond instant of the clock. - static Clock offset(Clock baseClock, Duration offsetDuration)
Obtains a clock based on the given clock with the duration added. - static Clock system(ZoneId zone)
Returns a clock that returns the current instant using best available system clock in the specified zone. - static Clock systemDefaultZone()
Returns a clock that returns the current instant using the best available system clock, converting to date and time using the default time-zone. - static Clock systemUTC()
Returns a clock that returns the current instant using the best available system clock, converting to date and time using the UTC time-zone. - static Clock tick(Clock baseClock, Duration tickDuration)
Returns a clock that returns instants from the specified clock truncated to the nearest occurrence of the specified duration. - static Clock tickMinutes(ZoneId zone)
Obtains a clock that returns the current instant ticking in whole minutes using best available system clock. - static Clock tickSeconds(ZoneId zone)
Returns a clock that returns the current instant ticking in whole seconds using best available system clock. - abstract Clock withZone(ZoneId zone)
Returns a copy of this clock with a different time-zone.
Java Time Clock tickSeconds(ZoneId)
java.time.Clock.tickSeconds(ZoneId)
The method Clock.tickSeconds(ZoneId zone) returns a clock that will tick in seconds using the best available clock (usually system clock).
Java Time Clock tick(Clock,Duration)
java.time.Clock.tick(Clock baseClock, Duration duration)
The method Clock.tick(Clock, Duration) returns a clock that will return instants from given baseClock truncated to given duration.
Java Time Clock systemUTC
java.time.Clock.systemUTC()
The method Clock.systemUTC() returns a clock that will use the best available system clock to convert instant into date and time using UTC time-zone.
Java Time Clock systemDefaultZone
java.time.Clock.systemDefaultZone()
The method Clock.systemDefaultZone() returns a clock that will use the best available system clock to convert instant into date and time using default time-zone.
Java Time Clock offset(Clock,Duration)
java.time.Clock.offset(Clock,Duration)
The method java.time.Clock.offset(Clock,Duration) returns a wrapper around given Clock with the specified Duration added. This clock implementation allows easily to jump into the past and future.
Java Time ZoneId getAvailableZoneIds
java.time.ZoneId.getAvailableZoneIds()
The method ZoneId.getAvailableZoneIds() returns set of available zone IDs, including all available region-based IDs. Usually passed to of(String zoneId) to create ZoneId.
Java Time Clock system(ZoneId)
java.time.Clock.system(ZoneId zone)
The method java.time.Clock.system(ZoneId zone) a clock that uses the best available system clock in the specified zone – never null.
Java time Clock fixed
java.time.Clock.fixed()
The method java.time.Clock.fixed() returns a clock that always returns the same time. This type of clock is mainly useful in testing.
