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/OpenJDK 8

Class Duration

All Implemented Interfaces:
Serializable, Comparable<Duration>, TemporalAmount
public final class Duration
extends Object
implements TemporalAmount, Comparable<Duration>, Serializable

A time-based amount of time, such as '34.5 seconds'.

This class models a quantity or amount of time in terms of seconds and nanoseconds. It can be accessed using other duration-based units, such as minutes and hours. In addition, the DAYS unit can be used and is treated as exactly equal to 24 hours, thus ignoring daylight savings effects. See Period for the date-based equivalent to this class.

A physical duration could be of infinite length. For practicality, the duration is stored with constraints similar to Instant. The duration uses nanosecond resolution with a maximum value of the seconds that can be held in a long. This is greater than the current estimated age of the universe.

The range of a duration requires the storage of a number larger than a long. To achieve this, the class stores a long representing seconds and an int representing nanosecond-of-second, which will always be between 0 and 999,999,999. The model is of a directed duration, meaning that the duration may be negative.

The duration is measured in "seconds", but these are not necessarily identical to the scientific "SI second" definition based on atomic clocks. This difference only impacts durations measured near a leap-second and should not affect most applications. See Instant for a discussion as to the meaning of the second and time-scales.

This is a value-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances of Duration may have unpredictable results and should be avoided. The equals method should be used for comparisons.

Implementation Requirements:
This class is immutable and thread-safe.
Since:
1.8

Fields

ZERO

public static final Duration ZERO

Constant for a duration of zero.

Methods

ofDays

public static Duration ofDays(long days)

Obtains a Duration representing a number of standard 24 hour days.

The seconds are calculated based on the standard definition of a day, where each day is 86400 seconds which implies a 24 hour day. The nanosecond in second field is set to zero.

Parameters:
days - the number of days, positive or negative
Returns:
a Duration, not null
Throws:
ArithmeticException - if the input days exceeds the capacity of Duration

ofHours

public static Duration ofHours(long hours)

Obtains a Duration representing a number of standard hours.

The seconds are calculated based on the standard definition of an hour, where each hour is 3600 seconds. The nanosecond in second field is set to zero.

Parameters:
hours - the number of hours, positive or negative
Returns:
a Duration, not null
Throws:
ArithmeticException - if the input hours exceeds the capacity of Duration

ofMinutes

public static Duration ofMinutes(long minutes)

Obtains a Duration representing a number of standard minutes.

The seconds are calculated based on the standard definition of a minute, where each minute is 60 seconds. The nanosecond in second field is set to zero.

Parameters:
minutes - the number of minutes, positive or negative
Returns:
a Duration, not null
Throws:
ArithmeticException - if the input minutes exceeds the capacity of Duration

ofSeconds

public static Duration ofSeconds(long seconds)

Obtains a Duration representing a number of seconds.

The nanosecond in second field is set to zero.

Parameters:
seconds - the number of seconds, positive or negative
Returns:
a Duration, not null

ofSeconds

public static Duration ofSeconds(long seconds,
                                 long nanoAdjustment)

Obtains a Duration representing a number of seconds and an adjustment in nanoseconds.

This method allows an arbitrary number of nanoseconds to be passed in. The factory will alter the values of the second and nanosecond in order to ensure that the stored nanosecond is in the range 0 to 999,999,999. For example, the following will result in the exactly the same duration:

Duration.ofSeconds(3, 1);
  Duration.ofSeconds(4, -999_999_999);
  Duration.ofSeconds(2, 1000_000_001);
Parameters:
seconds - the number of seconds, positive or negative
nanoAdjustment - the nanosecond adjustment to the number of seconds, positive or negative
Returns:
a Duration, not null
Throws:
ArithmeticException - if the adjustment causes the seconds to exceed the capacity of Duration

ofMillis

public static Duration ofMillis(long millis)

Obtains a Duration representing a number of milliseconds.

The seconds and nanoseconds are extracted from the specified milliseconds.

Parameters:
millis - the number of milliseconds, positive or negative
Returns:
a Duration, not null

ofNanos

public static Duration ofNanos(long nanos)

Obtains a Duration representing a number of nanoseconds.

The seconds and nanoseconds are extracted from the specified nanoseconds.

Parameters:
nanos - the number of nanoseconds, positive or negative
Returns:
a Duration, not null

of

public static Duration of(long amount,
                          TemporalUnit unit)

Obtains a Duration representing an amount in the specified unit.

The parameters represent the two parts of a phrase like '6 Hours'. For example:

Duration.of(3, SECONDS);
  Duration.of(465, HOURS);
Only a subset of units are accepted by this method. The unit must either have an exact duration or be ChronoUnit.DAYS which is treated as 24 hours. Other units throw an exception.
Parameters:
amount - the amount of the duration, measured in terms of the unit, positive or negative
unit - the unit that the duration is measured in, must have an exact duration, not null
Returns:
a Duration, not null
Throws:
DateTimeException - if the period unit has an estimated duration
ArithmeticException - if a numeric overflow occurs

from

public static Duration from(TemporalAmount amount)

Obtains an instance of Duration from a temporal amount.

This obtains a duration based on the specified amount. A TemporalAmount represents an amount of time, which may be date-based or time-based, which this factory extracts to a duration.

The conversion loops around the set of units from the amount and uses the duration of the unit to calculate the total Duration. Only a subset of units are accepted by this method. The unit must either have an exact duration or be ChronoUnit.DAYS which is treated as 24 hours. If any other units are found then an exception is thrown.

Parameters:
amount - the temporal amount to convert, not null
Returns:
the equivalent duration, not null
Throws:
DateTimeException - if unable to convert to a Duration
ArithmeticException - if numeric overflow occurs

parse

public static Duration parse(CharSequence text)

Obtains a Duration from a text string such as PnDTnHnMn.nS.

This will parse a textual representation of a duration, including the string produced by toString(). The formats accepted are based on the ISO-8601 duration format PnDTnHnMn.nS with days considered to be exactly 24 hours.

The string starts with an optional sign, denoted by the ASCII negative or positive symbol. If negative, the whole period is negated. The ASCII letter "P" is next in upper or lower case. There are then four sections, each consisting of a number and a suffix. The sections have suffixes in ASCII of "D", "H", "M" and "S" for days, hours, minutes and seconds, accepted in upper or lower case. The suffixes must occur in order. The ASCII letter "T" must occur before the first occurrence, if any, of an hour, minute or second section. At least one of the four sections must be present, and if "T" is present there must be at least one section after the "T". The number part of each section must consist of one or more ASCII digits. The number may be prefixed by the ASCII negative or positive symbol. The number of days, hours and minutes must parse to an long. The number of seconds must parse to an long with optional fraction. The decimal point may be either a dot or a comma. The fractional part may have from zero to 9 digits.

The leading plus/minus sign, and negative values for other units are not part of the ISO-8601 standard.

Examples:

"PT20.345S" -- parses as "20.345 seconds"
    "PT15M"     -- parses as "15 minutes" (where a minute is 60 seconds)
    "PT10H"     -- parses as "10 hours" (where an hour is 3600 seconds)
    "P2D"       -- parses as "2 days" (where a day is 24 hours or 86400 seconds)
    "P2DT3H4M"  -- parses as "2 days, 3 hours and 4 minutes"
    "P-6H3M"    -- parses as "-6 hours and +3 minutes"
    "-P6H3M"    -- parses as "-6 hours and -3 minutes"
    "-P-6H+3M"  -- parses as "+6 hours and -3 minutes"
Parameters:
text - the text to parse, not null
Returns:
the parsed duration, not null
Throws:
DateTimeParseException - if the text cannot be parsed to a duration

between

public static Duration between(Temporal startInclusive,
                               Temporal endExclusive)

Obtains a Duration representing the duration between two temporal objects.

This calculates the duration between two temporal objects. If the objects are of different types, then the duration is calculated based on the type of the first object. For example, if the first argument is a LocalTime then the second argument is converted to a LocalTime.

The specified temporal objects must support the SECONDS unit. For full accuracy, either the NANOS unit or the NANO_OF_SECOND field should be supported.

The result of this method can be a negative period if the end is before the start. To guarantee to obtain a positive duration call abs() on the result.

Parameters:
startInclusive - the start instant, inclusive, not null
endExclusive - the end instant, exclusive, not null
Returns:
a Duration, not null
Throws:
DateTimeException - if the seconds between the temporals cannot be obtained
ArithmeticException - if the calculation exceeds the capacity of Duration

get

public long get(TemporalUnit unit)

Gets the value of the requested unit.

This returns a value for each of the two supported units, SECONDS and NANOS. All other units throw an exception.

Specified by:
get in interface TemporalAmount
Parameters:
unit - the TemporalUnit for which to return the value
Returns:
the long value of the unit
Throws:
DateTimeException - if the unit is not supported
UnsupportedTemporalTypeException - if the unit is not supported

getUnits

public List<TemporalUnit> getUnits()

Gets the set of units supported by this duration.

The supported units are SECONDS, and NANOS. They are returned in the order seconds, nanos.

This set can be used in conjunction with get(TemporalUnit) to access the entire state of the duration.

Specified by:
getUnits in interface TemporalAmount
Returns:
a list containing the seconds and nanos units, not null

isZero

public boolean isZero()

Checks if this duration is zero length.

A Duration represents a directed distance between two points on the time-line and can therefore be positive, zero or negative. This method checks whether the length is zero.

Returns:
true if this duration has a total length equal to zero

isNegative

public boolean isNegative()

Checks if this duration is negative, excluding zero.

A Duration represents a directed distance between two points on the time-line and can therefore be positive, zero or negative. This method checks whether the length is less than zero.

Returns:
true if this duration has a total length less than zero

getSeconds

public long getSeconds()

Gets the number of seconds in this duration.

The length of the duration is stored using two fields - seconds and nanoseconds. The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to the length in seconds. The total duration is defined by calling this method and getNano().

A Duration represents a directed distance between two points on the time-line. A negative duration is expressed by the negative sign of the seconds part. A duration of -1 nanosecond is stored as -1 seconds plus 999,999,999 nanoseconds.

Returns:
the whole seconds part of the length of the duration, positive or negative

getNano

public int getNano()

Gets the number of nanoseconds within the second in this duration.

The length of the duration is stored using two fields - seconds and nanoseconds. The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to the length in seconds. The total duration is defined by calling this method and getSeconds().

A Duration represents a directed distance between two points on the time-line. A negative duration is expressed by the negative sign of the seconds part. A duration of -1 nanosecond is stored as -1 seconds plus 999,999,999 nanoseconds.

Returns:
the nanoseconds within the second part of the length of the duration, from 0 to 999,999,999

withSeconds

public Duration withSeconds(long seconds)

Returns a copy of this duration with the specified amount of seconds.

This returns a duration with the specified seconds, retaining the nano-of-second part of this duration.

This instance is immutable and unaffected by this method call.

Parameters:
seconds - the seconds to represent, may be negative
Returns:
a Duration based on this period with the requested seconds, not null

withNanos

public Duration withNanos(int nanoOfSecond)

Returns a copy of this duration with the specified nano-of-second.

This returns a duration with the specified nano-of-second, retaining the seconds part of this duration.

This instance is immutable and unaffected by this method call.

Parameters:
nanoOfSecond - the nano-of-second to represent, from 0 to 999,999,999
Returns:
a Duration based on this period with the requested nano-of-second, not null
Throws:
DateTimeException - if the nano-of-second is invalid

plus

public Duration plus(Duration duration)

Returns a copy of this duration with the specified duration added.

This instance is immutable and unaffected by this method call.

Parameters:
duration - the duration to add, positive or negative, not null
Returns:
a Duration based on this duration with the specified duration added, not null
Throws:
ArithmeticException - if numeric overflow occurs

plus

public Duration plus(long amountToAdd,
                     TemporalUnit unit)

Returns a copy of this duration with the specified duration added.

The duration amount is measured in terms of the specified unit. Only a subset of units are accepted by this method. The unit must either have an exact duration or be ChronoUnit.DAYS which is treated as 24 hours. Other units throw an exception.

This instance is immutable and unaffected by this method call.

Parameters:
amountToAdd - the amount to add, measured in terms of the unit, positive or negative
unit - the unit that the amount is measured in, must have an exact duration, not null
Returns:
a Duration based on this duration with the specified duration added, not null
Throws:
UnsupportedTemporalTypeException - if the unit is not supported
ArithmeticException - if numeric overflow occurs

plusDays

public Duration plusDays(long daysToAdd)

Returns a copy of this duration with the specified duration in standard 24 hour days added.

The number of days is multiplied by 86400 to obtain the number of seconds to add. This is based on the standard definition of a day as 24 hours.

This instance is immutable and unaffected by this method call.

Parameters:
daysToAdd - the days to add, positive or negative
Returns:
a Duration based on this duration with the specified days added, not null
Throws:
ArithmeticException - if numeric overflow occurs

plusHours

public Duration plusHours(long hoursToAdd)

Returns a copy of this duration with the specified duration in hours added.

This instance is immutable and unaffected by this method call.

Parameters:
hoursToAdd - the hours to add, positive or negative
Returns:
a Duration based on this duration with the specified hours added, not null
Throws:
ArithmeticException - if numeric overflow occurs

plusMinutes

public Duration plusMinutes(long minutesToAdd)

Returns a copy of this duration with the specified duration in minutes added.

This instance is immutable and unaffected by this method call.

Parameters:
minutesToAdd - the minutes to add, positive or negative
Returns:
a Duration based on this duration with the specified minutes added, not null
Throws:
ArithmeticException - if numeric overflow occurs

plusSeconds

public Duration plusSeconds(long secondsToAdd)

Returns a copy of this duration with the specified duration in seconds added.

This instance is immutable and unaffected by this method call.

Parameters:
secondsToAdd - the seconds to add, positive or negative
Returns:
a Duration based on this duration with the specified seconds added, not null
Throws:
ArithmeticException - if numeric overflow occurs

plusMillis

public Duration plusMillis(long millisToAdd)

Returns a copy of this duration with the specified duration in milliseconds added.

This instance is immutable and unaffected by this method call.

Parameters:
millisToAdd - the milliseconds to add, positive or negative
Returns:
a Duration based on this duration with the specified milliseconds added, not null
Throws:
ArithmeticException - if numeric overflow occurs

plusNanos

public Duration plusNanos(long nanosToAdd)

Returns a copy of this duration with the specified duration in nanoseconds added.

This instance is immutable and unaffected by this method call.

Parameters:
nanosToAdd - the nanoseconds to add, positive or negative
Returns:
a Duration based on this duration with the specified nanoseconds added, not null
Throws:
ArithmeticException - if numeric overflow occurs

minus

public Duration minus(Duration duration)

Returns a copy of this duration with the specified duration subtracted.

This instance is immutable and unaffected by this method call.

Parameters:
duration - the duration to subtract, positive or negative, not null
Returns:
a Duration based on this duration with the specified duration subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minus

public Duration minus(long amountToSubtract,
                      TemporalUnit unit)

Returns a copy of this duration with the specified duration subtracted.

The duration amount is measured in terms of the specified unit. Only a subset of units are accepted by this method. The unit must either have an exact duration or be ChronoUnit.DAYS which is treated as 24 hours. Other units throw an exception.

This instance is immutable and unaffected by this method call.

Parameters:
amountToSubtract - the amount to subtract, measured in terms of the unit, positive or negative
unit - the unit that the amount is measured in, must have an exact duration, not null
Returns:
a Duration based on this duration with the specified duration subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minusDays

public Duration minusDays(long daysToSubtract)

Returns a copy of this duration with the specified duration in standard 24 hour days subtracted.

The number of days is multiplied by 86400 to obtain the number of seconds to subtract. This is based on the standard definition of a day as 24 hours.

This instance is immutable and unaffected by this method call.

Parameters:
daysToSubtract - the days to subtract, positive or negative
Returns:
a Duration based on this duration with the specified days subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minusHours

public Duration minusHours(long hoursToSubtract)

Returns a copy of this duration with the specified duration in hours subtracted.

The number of hours is multiplied by 3600 to obtain the number of seconds to subtract.

This instance is immutable and unaffected by this method call.

Parameters:
hoursToSubtract - the hours to subtract, positive or negative
Returns:
a Duration based on this duration with the specified hours subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minusMinutes

public Duration minusMinutes(long minutesToSubtract)

Returns a copy of this duration with the specified duration in minutes subtracted.

The number of hours is multiplied by 60 to obtain the number of seconds to subtract.

This instance is immutable and unaffected by this method call.

Parameters:
minutesToSubtract - the minutes to subtract, positive or negative
Returns:
a Duration based on this duration with the specified minutes subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minusSeconds

public Duration minusSeconds(long secondsToSubtract)

Returns a copy of this duration with the specified duration in seconds subtracted.

This instance is immutable and unaffected by this method call.

Parameters:
secondsToSubtract - the seconds to subtract, positive or negative
Returns:
a Duration based on this duration with the specified seconds subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minusMillis

public Duration minusMillis(long millisToSubtract)

Returns a copy of this duration with the specified duration in milliseconds subtracted.

This instance is immutable and unaffected by this method call.

Parameters:
millisToSubtract - the milliseconds to subtract, positive or negative
Returns:
a Duration based on this duration with the specified milliseconds subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

minusNanos

public Duration minusNanos(long nanosToSubtract)

Returns a copy of this duration with the specified duration in nanoseconds subtracted.

This instance is immutable and unaffected by this method call.

Parameters:
nanosToSubtract - the nanoseconds to subtract, positive or negative
Returns:
a Duration based on this duration with the specified nanoseconds subtracted, not null
Throws:
ArithmeticException - if numeric overflow occurs

multipliedBy

public Duration multipliedBy(long multiplicand)

Returns a copy of this duration multiplied by the scalar.

This instance is immutable and unaffected by this method call.

Parameters:
multiplicand - the value to multiply the duration by, positive or negative
Returns:
a Duration based on this duration multiplied by the specified scalar, not null
Throws:
ArithmeticException - if numeric overflow occurs

dividedBy

public Duration dividedBy(long divisor)

Returns a copy of this duration divided by the specified value.

This instance is immutable and unaffected by this method call.

Parameters:
divisor - the value to divide the duration by, positive or negative, not zero
Returns:
a Duration based on this duration divided by the specified divisor, not null
Throws:
ArithmeticException - if the divisor is zero or if numeric overflow occurs

negated

public Duration negated()

Returns a copy of this duration with the length negated.

This method swaps the sign of the total length of this duration. For example, PT1.3S will be returned as PT-1.3S.

This instance is immutable and unaffected by this method call.

Returns:
a Duration based on this duration with the amount negated, not null
Throws:
ArithmeticException - if numeric overflow occurs

abs

public Duration abs()

Returns a copy of this duration with a positive length.

This method returns a positive duration by effectively removing the sign from any negative total length. For example, PT-1.3S will be returned as PT1.3S.

This instance is immutable and unaffected by this method call.

Returns:
a Duration based on this duration with an absolute length, not null
Throws:
ArithmeticException - if numeric overflow occurs

addTo

public Temporal addTo(Temporal temporal)

Adds this duration to the specified temporal object.

This returns a temporal object of the same observable type as the input with this duration added.

In most cases, it is clearer to reverse the calling pattern by using Temporal.plus(TemporalAmount).

// these two lines are equivalent, but the second approach is recommended
   dateTime = thisDuration.addTo(dateTime);
   dateTime = dateTime.plus(thisDuration);

The calculation will add the seconds, then nanos. Only non-zero amounts will be added.

This instance is immutable and unaffected by this method call.

Specified by:
addTo in interface TemporalAmount
Parameters:
temporal - the temporal object to adjust, not null
Returns:
an object of the same type with the adjustment made, not null
Throws:
DateTimeException - if unable to add
ArithmeticException - if numeric overflow occurs

subtractFrom

public Temporal subtractFrom(Temporal temporal)

Subtracts this duration from the specified temporal object.

This returns a temporal object of the same observable type as the input with this duration subtracted.

In most cases, it is clearer to reverse the calling pattern by using Temporal.minus(TemporalAmount).

// these two lines are equivalent, but the second approach is recommended
   dateTime = thisDuration.subtractFrom(dateTime);
   dateTime = dateTime.minus(thisDuration);

The calculation will subtract the seconds, then nanos. Only non-zero amounts will be added.

This instance is immutable and unaffected by this method call.

Specified by:
subtractFrom in interface TemporalAmount
Parameters:
temporal - the temporal object to adjust, not null
Returns:
an object of the same type with the adjustment made, not null
Throws:
DateTimeException - if unable to subtract
ArithmeticException - if numeric overflow occurs

toDays

public long toDays()

Gets the number of days in this duration.

This returns the total number of days in the duration by dividing the number of seconds by 86400. This is based on the standard definition of a day as 24 hours.

This instance is immutable and unaffected by this method call.

Returns:
the number of days in the duration, may be negative

toHours

public long toHours()

Gets the number of hours in this duration.

This returns the total number of hours in the duration by dividing the number of seconds by 3600.

This instance is immutable and unaffected by this method call.

Returns:
the number of hours in the duration, may be negative

toMinutes

public long toMinutes()

Gets the number of minutes in this duration.

This returns the total number of minutes in the duration by dividing the number of seconds by 60.

This instance is immutable and unaffected by this method call.

Returns:
the number of minutes in the duration, may be negative

toMillis

public long toMillis()

Converts this duration to the total length in milliseconds.

If this duration is too large to fit in a long milliseconds, then an exception is thrown.

If this duration has greater than millisecond precision, then the conversion will drop any excess precision information as though the amount in nanoseconds was subject to integer division by one million.

Returns:
the total length of the duration in milliseconds
Throws:
ArithmeticException - if numeric overflow occurs

toNanos

public long toNanos()

Converts this duration to the total length in nanoseconds expressed as a long.

If this duration is too large to fit in a long nanoseconds, then an exception is thrown.

Returns:
the total length of the duration in nanoseconds
Throws:
ArithmeticException - if numeric overflow occurs

compareTo

public int compareTo(Duration otherDuration)

Compares this duration to the specified Duration.

The comparison is based on the total length of the durations. It is "consistent with equals", as defined by Comparable.

Specified by:
compareTo in interface Comparable<Duration>
Parameters:
otherDuration - the other duration to compare to, not null
Returns:
the comparator value, negative if less, positive if greater

equals

public boolean equals(Object otherDuration)

Checks if this duration is equal to the specified Duration.

The comparison is based on the total length of the durations.

Overrides:
equals in class Object
Parameters:
otherDuration - the other duration, null returns false
Returns:
true if the other duration is equal to this one
See Also:
Object.hashCode(), HashMap

hashCode

public int hashCode()

A hash code for this duration.

Overrides:
hashCode in class Object
Returns:
a suitable hash code
See Also:
Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

toString

public String toString()

A string representation of this duration using ISO-8601 seconds based representation, such as PT8H6M12.345S.

The format of the returned string will be PTnHnMnS, where n is the relevant hours, minutes or seconds part of the duration. Any fractional seconds are placed after a decimal point i the seconds section. If a section has a zero value, it is omitted. The hours, minutes and seconds will all have the same sign.

Examples:

"20.345 seconds"                 -- "PT20.345S
    "15 minutes" (15 * 60 seconds)   -- "PT15M"
    "10 hours" (10 * 3600 seconds)   -- "PT10H"
    "2 days" (2 * 86400 seconds)     -- "PT48H"
Note that multiples of 24 hours are not output as days to avoid confusion with Period.
Overrides:
toString in class Object
Returns:
an ISO-8601 representation of this duration, not null

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