java.util.concurrent

Enum TimeUnit

  • All Implemented Interfaces:
    Serializable, Comparable<TimeUnit> 

    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 Detail

      • 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

      • HOURS

        public static final TimeUnit HOURS
        Time unit representing sixty minutes

      • DAYS

        public static final TimeUnit DAYS
        Time unit representing twenty four hours

    • Method Detail

      • values

        public static TimeUnit[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows: 
        for (TimeUnit c : TimeUnit.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static TimeUnit valueOf(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (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 type 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.

      • toNanos

        public long toNanos(long duration)
        Equivalent to NANOSECONDS.convert(duration, this).
        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)
        Equivalent to MICROSECONDS.convert(duration, this).
        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)
        Equivalent to MILLISECONDS.convert(duration, this).
        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)
        Equivalent to SECONDS.convert(duration, this).
        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)
        Equivalent to MINUTES.convert(duration, this).
        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)
        Equivalent to HOURS.convert(duration, this).
        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)
        Equivalent to DAYS.convert(duration, this).
        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 synchronized Object poll(long timeout, TimeUnit unit) throws InterruptedException { while (empty) { unit.timedWait(this, 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