Module java.base

Package java.util.concurrent

Enum TimeUnit

java.lang.Object

java.lang.Enum<TimeUnit>

java.util.concurrent.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 Summary

Enum Constants

Enum Constant	Description
DAYS	Time unit representing twenty four hours.
HOURS	Time unit representing sixty minutes.
MICROSECONDS	Time unit representing one thousandth of a millisecond.
MILLISECONDS	Time unit representing one thousandth of a second.
MINUTES	Time unit representing sixty seconds.
NANOSECONDS	Time unit representing one thousandth of a microsecond.
SECONDS	Time unit representing one second.

Method Summary

Modifier and Type	Method	Description
long	convert(long sourceDuration, TimeUnit sourceUnit)	Converts the given time duration in the given unit to this unit.
long	convert(Duration duration)	Converts the given time duration to this unit.
static TimeUnit	of(ChronoUnit chronoUnit)	Converts a ChronoUnit to the equivalent TimeUnit.
void	sleep(long timeout)	Performs a Thread.sleep using this time unit.
void	timedJoin(Thread thread, long timeout)	Performs a timed Thread.join using this time unit.
void	timedWait(Object obj, long timeout)	Performs a timed Object.wait using this time unit.
ChronoUnit	toChronoUnit()	Converts this TimeUnit to the equivalent ChronoUnit.
long	toDays(long duration)	Equivalent to DAYS.convert(duration, this).
long	toHours(long duration)	Equivalent to HOURS.convert(duration, this).
long	toMicros(long duration)	Equivalent to MICROSECONDS.convert(duration, this).
long	toMillis(long duration)	Equivalent to MILLISECONDS.convert(duration, this).
long	toMinutes(long duration)	Equivalent to MINUTES.convert(duration, this).
long	toNanos(long duration)	Equivalent to NANOSECONDS.convert(duration, this).
long	toSeconds(long duration)	Equivalent to SECONDS.convert(duration, this).
static TimeUnit	valueOf(String name)	Returns the enum constant of this type with the specified name.
static TimeUnit[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods declared in class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods declared in class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

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.

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 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.

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)

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 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