Package org.apache.maven.api

Class MonotonicClock

java.lang.Object
java.time.Clock
org.apache.maven.api.MonotonicClock
All Implemented Interfaces:
InstantSource
public class MonotonicClock extends Clock
A Clock implementation that combines monotonic timing with wall-clock time.

This class provides precise time measurements using System.nanoTime() while maintaining wall-clock time information in UTC. The wall-clock time is computed from the monotonic duration since system start to ensure consistency between time measurements.

This implementation is singleton-based and always uses UTC timezone. The clock cannot be adjusted to different timezones to maintain consistent monotonic behavior. Users needing local time representation should convert the result of instant() to their desired timezone: 


 Instant now = MonotonicClock.now();
 ZonedDateTime local = now.atZone(ZoneId.systemDefault());
See Also:

  • Method Details

    • get

      public static MonotonicClock get()
      Returns the singleton instance of MonotonicClock.
      Returns:
      the monotonic clock instance

    • now

      public static Instant now()
      Returns the current instant from the monotonic clock. This is a convenience method equivalent to get().instant().
      Returns:
      the current instant using monotonic timing

    • instant

      public Instant instant()
      Returns a monotonically increasing instant.

      The returned instant is calculated by adding the elapsed nanoseconds since clock creation to the initial wall clock time. This ensures that the time never goes backwards and maintains a consistent relationship with the wall clock time.

      Specified by:
      instant in interface InstantSource
      Specified by:
      instant in class Clock
      Returns:
      the current instant using monotonic timing

    • getZone

      public ZoneId getZone()
      Returns the zone ID of this clock, which is always UTC.
      Specified by:
      getZone in class Clock
      Returns:
      the UTC zone ID

    • withZone

      public Clock withZone(ZoneId zone)
      Returns this clock since timezone adjustments are not supported.

      This implementation maintains UTC time to ensure monotonic behavior. The provided zone parameter is ignored.

      Specified by:
      withZone in interface InstantSource
      Specified by:
      withZone in class Clock
      Parameters:
      zone - the target timezone (ignored)
      Returns:
      this clock instance