Module java.base

Enum Class TimeUnit

java.lang.Object
java.lang.Enum<TimeUnit>
java.util.concurrent.TimeUnit
All Implemented Interfaces:
Serializable, Comparable<TimeUnit>, Constable

public enum TimeUnit extends Enum<TimeUnit>
A TimeUnit represents time durations at a given unit of granularity and provides utility methods to convert across units, and to perform timing and delay operations in these units. A TimeUnit does not maintain time information, but only helps organize and use time representations that may be maintained separately across various contexts. A nanosecond is defined as one thousandth of a microsecond, a microsecond as one thousandth of a millisecond, a millisecond as one thousandth of a second, a minute as sixty seconds, an hour as sixty minutes, and a day as twenty four hours.

A TimeUnit is mainly used to inform time-based methods how a given timing parameter should be interpreted. For example, the following code will timeout in 50 milliseconds if the lock is not available:

 
 Lock lock = ...;
 if (lock.tryLock(50L, TimeUnit.MILLISECONDS)) ...
while this code will timeout in 50 seconds:
 
 Lock lock = ...;
 if (lock.tryLock(50L, TimeUnit.SECONDS)) ...
Note however, that there is no guarantee that a particular timeout implementation will be able to notice the passage of time at the same granularity as the given TimeUnit.

Since:
1.5
  • Enum Constant Details

    • NANOSECONDS

      public static final TimeUnit NANOSECONDS
      Time unit representing one thousandth of a microsecond.
    • MICROSECONDS

      public static final TimeUnit MICROSECONDS
      Time unit representing one thousandth of a millisecond.
    • MILLISECONDS

      public static final TimeUnit MILLISECONDS
      Time unit representing one thousandth of a second.
    • SECONDS

      public static final TimeUnit SECONDS
      Time unit representing one second.
    • MINUTES

      public static final TimeUnit MINUTES
      Time unit representing sixty seconds.
      Since:
      1.6
    • HOURS

      public static final TimeUnit HOURS
      Time unit representing sixty minutes.
      Since:
      1.6
    • DAYS

      public static final TimeUnit DAYS
      Time unit representing twenty four hours.
      Since:
      1.6
  • Method Details

    • values

      public static TimeUnit[] values()
      Returns an array containing the constants of this enum class, in the order they are declared.
      Returns:
      an array containing the constants of this enum class, in the order they are declared
    • valueOf

      public static TimeUnit valueOf(String name)
      Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum class has no constant with the specified name
      NullPointerException - if the argument is null
    • convert

      public long convert(long sourceDuration, TimeUnit sourceUnit)
      Converts the given time duration in the given unit to this unit. Conversions from finer to coarser granularities truncate, so lose precision. For example, converting 999 milliseconds to seconds results in 0. Conversions from coarser to finer granularities with arguments that would numerically overflow saturate to Long.MIN_VALUE if negative or Long.MAX_VALUE if positive.

      For example, to convert 10 minutes to milliseconds, use: TimeUnit.MILLISECONDS.convert(10L, TimeUnit.MINUTES)

      Parameters:
      sourceDuration - the time duration in the given sourceUnit
      sourceUnit - the unit of the sourceDuration argument
      Returns:
      the converted duration in this unit, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
    • convert

      public long convert(Duration duration)
      Converts the given time duration to this unit.

      For any TimeUnit unit, unit.convert(Duration.ofNanos(n)) is equivalent to unit.convert(n, NANOSECONDS), and unit.convert(Duration.of(n, unit.toChronoUnit())) is equivalent to n (in the absence of overflow).

      API Note:
      This method differs from Duration.toNanos() in that it does not throw ArithmeticException on numeric overflow.
      Parameters:
      duration - the time duration
      Returns:
      the converted duration in this unit, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
      Throws:
      NullPointerException - if duration is null
      Since:
      11
      See Also:
      Duration.of(long,TemporalUnit)
    • toNanos

      public long toNanos(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
    • toMicros

      public long toMicros(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
    • toMillis

      public long toMillis(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
    • toSeconds

      public long toSeconds(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
    • toMinutes

      public long toMinutes(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
      Since:
      1.6
    • toHours

      public long toHours(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.
      Since:
      1.6
    • toDays

      public long toDays(long duration)
      Parameters:
      duration - the duration
      Returns:
      the converted duration
      Since:
      1.6
    • timedWait

      public void timedWait(Object obj, long timeout) throws InterruptedException
      Performs a timed Object.wait using this time unit. This is a convenience method that converts timeout arguments into the form required by the Object.wait method.

      For example, you could implement a blocking poll method (see BlockingQueue.poll) using:

       
       public E poll(long timeout, TimeUnit unit)
           throws InterruptedException {
         synchronized (lock) {
           while (isEmpty()) {
             unit.timedWait(lock, timeout);
             ...
           }
         }
       }

      Parameters:
      obj - the object to wait on
      timeout - the maximum time to wait. If less than or equal to zero, do not wait at all.
      Throws:
      InterruptedException - if interrupted while waiting
    • timedJoin

      public void timedJoin(Thread thread, long timeout) throws InterruptedException
      Performs a timed Thread.join using this time unit. This is a convenience method that converts time arguments into the form required by the Thread.join method.
      Parameters:
      thread - the thread to wait for
      timeout - the maximum time to wait. If less than or equal to zero, do not wait at all.
      Throws:
      InterruptedException - if interrupted while waiting
    • sleep

      public void sleep(long timeout) throws InterruptedException
      Performs a Thread.sleep using this time unit. This is a convenience method that converts time arguments into the form required by the Thread.sleep method.
      Parameters:
      timeout - the minimum time to sleep. If less than or equal to zero, do not sleep at all.
      Throws:
      InterruptedException - if interrupted while sleeping
    • toChronoUnit

      public ChronoUnit toChronoUnit()
      Converts this TimeUnit to the equivalent ChronoUnit.
      Returns:
      the converted equivalent ChronoUnit
      Since:
      9
    • of

      public static TimeUnit of(ChronoUnit chronoUnit)
      Converts a ChronoUnit to the equivalent TimeUnit.
      Parameters:
      chronoUnit - the ChronoUnit to convert
      Returns:
      the converted equivalent TimeUnit
      Throws:
      IllegalArgumentException - if chronoUnit has no equivalent TimeUnit
      NullPointerException - if chronoUnit is null
      Since:
      9