public abstract Class Duration

Computes a new duration whose value is this+rhs.

For example,

"1 day" + "-3 days" = "-2 days"
"1 year" + "1 day" = "1 year and 1 day"
"-(1 hour,50 minutes)" + "-20 minutes" = "-(1 hours,70 minutes)"
"15 hours" + "-3 days" = "-(2 days,9 hours)"
"1 year" + "-1 day" = IllegalStateException

Since there's no way to meaningfully subtract 1 day from 1 month, there are cases where the operation fails in IllegalStateException.

Formally, the computation is defined as follows.

Firstly, we can assume that two Durations to be added are both positive without losing generality (i.e., (-X)+Y=Y-X, X+(-Y)=X-Y, (-X)+(-Y)=-(X+Y))

Addition of two positive Durations are simply defined as field by field addition where missing fields are treated as 0.

A field of the resulting Duration will be unset if and only if respective fields of two input Durations are unset.

Note that lhs.add(rhs) will be always successful if lhs.signum()*rhs.signum()!=-1 or both of them are normalized.

Parameters

rhs:Duration

Duration to add to this Duration

Returns:Duration

non-null valid Duration object.

Exceptions

NullPointerException:

If the rhs parameter is null.

IllegalStateException:

If two durations cannot be meaningfully added. For example, adding negative one day to one month causes this exception.

See Also

subtract(Duration)

Adds this duration to a Calendar object.

Calls java.util.Calendar#add(int, int) in the order of YEARS, MONTHS, DAYS, HOURS, MINUTES, SECONDS, and MILLISECONDS if those fields are present. Because the Calendar class uses int to hold values, there are cases where this method won't work correctly (for example if values of fields exceed the range of int.)

Also, since this duration class is a Gregorian duration, this method will not work correctly if the given Calendar object is based on some other calendar systems.

Any fractional parts of this Duration object beyond milliseconds will be simply ignored. For example, if this duration is "P1.23456S", then 1 is added to SECONDS, 234 is added to MILLISECONDS, and the rest will be unused.

Note that because Calendar#add(int, int) is using int, Duration with values beyond the range of int in its fields will cause overflow/underflow to the given Calendar. XMLGregorianCalendar#add(Duration) provides the same basic operation as this method while avoiding the overflow/underflow issues.

Parameters

calendar:Calendar

A calendar object whose value will be modified.

Exceptions

NullPointerException:

if the calendar parameter is null.

Adds this duration to a Date object.

The given date is first converted into a java.util.GregorianCalendar, then the duration is added exactly like the addTo(Calendar) method.

The updated time instant is then converted back into a Date object and used to update the given Date object.

This somewhat redundant computation is necessary to unambiguously determine the duration of months and years.

Parameters

date:Date

A date object whose value will be modified.

Exceptions

NullPointerException:

if the date parameter is null.

Partial order relation comparison with this Duration instance.

Comparison result must be in accordance with W3C XML Schema 1.0 Part 2, Section 3.2.7.6.2, Order relation on duration.

Return:

• DatatypeConstants#LESSER if this Duration is shorter than duration parameter
• DatatypeConstants#EQUAL if this Duration is equal to duration parameter
• DatatypeConstants#GREATER if this Duration is longer than duration parameter
• DatatypeConstants#INDETERMINATE if a conclusive partial order relation cannot be determined

Parameters

duration:Duration

to compare

Returns:int

the relationship between this Duration and duration parameter as DatatypeConstants#LESSER, DatatypeConstants#EQUAL, DatatypeConstants#GREATER or DatatypeConstants#INDETERMINATE.

Exceptions

UnsupportedOperationException:

If the underlying implementation cannot reasonably process the request, e.g. W3C XML Schema allows for arbitrarily large/small/precise values, the request may be beyond the implementations capability.

NullPointerException:

if duration is null.

See Also

isShorterThan(Duration), isLongerThan(Duration)

Overrides java.lang.Object.equals.

Checks if this duration object has the same duration as another Duration object.

For example, "P1D" (1 day) is equal to "PT24H" (24 hours).

Duration X is equal to Y if and only if time instant t+X and t+Y are the same for all the test time instants specified in the section 3.2.6.2 of the XML Schema 1.0 specification.

Note that there are cases where two Durations are "incomparable" to each other, like one month and 30 days. For example,

!new Duration("P1M").isShorterThan(new Duration("P30D"))
!new Duration("P1M").isLongerThan(new Duration("P30D"))
!new Duration("P1M").equals(new Duration("P30D"))

Parameters

duration:Object

The object to compare this Duration against.

Returns:boolean

true if this duration is the same length as duration. false if duration is null, is not a Duration object, or its length is different from this duration.

Exceptions

UnsupportedOperationException:

If the underlying implementation cannot reasonably process the request, e.g. W3C XML Schema allows for arbitrarily large/small/precise values, the request may be beyond the implementations capability.

See Also

compare(Duration duration)

Obtains the value of the DAYS field as an integer value, or 0 if not present. This method works just like getYears() except that this method works on the DAYS field.

Returns:int

Days of this Duration.

Gets the value of a field. Fields of a duration object may contain arbitrary large value. Therefore this method is designed to return a Number object. In case of YEARS, MONTHS, DAYS, HOURS, and MINUTES, the returned number will be a non-negative integer. In case of seconds, the returned number may be a non-negative decimal value.

Parameters

field:DatatypeConstants.Field

one of the six Field constants (YEARS,MONTHS,DAYS,HOURS, MINUTES, or SECONDS.)

Returns:Number

If the specified field is present, this method returns a non-null non-negative Number object that represents its value. If it is not present, return null. For YEARS, MONTHS, DAYS, HOURS, and MINUTES, this method returns a java.math.BigInteger object. For SECONDS, this method returns a java.math.BigDecimal.

Exceptions

NullPointerException:

If the field is null.

Obtains the value of the HOURS field as an integer value, or 0 if not present. This method works just like getYears() except that this method works on the HOURS field.

Returns:int

Hours of this Duration.

Obtains the value of the MINUTES field as an integer value, or 0 if not present. This method works just like getYears() except that this method works on the MINUTES field.

Returns:int

Minutes of this Duration.

Obtains the value of the MONTHS field as an integer value, or 0 if not present. This method works just like getYears() except that this method works on the MONTHS field.

Returns:int

Months of this Duration.

Obtains the value of the SECONDS field as an integer value, or 0 if not present. This method works just like getYears() except that this method works on the SECONDS field.

Returns:int

seconds in the integer value. The fraction of seconds will be discarded (for example, if the actual value is 2.5, this method returns 2)

Returns the sign of this duration in -1,0, or 1.

Returns:int

-1 if this duration is negative, 0 if the duration is zero, and 1 if the duration is positive.

Returns the length of the duration in milli-seconds.

If the seconds field carries more digits than milli-second order, those will be simply discarded (or in other words, rounded to zero.) For example, for any Calendar value x,

new Duration("PT10.00099S").getTimeInMills(x) == 10000
new Duration("-PT10.00099S").getTimeInMills(x) == -10000

Note that this method uses the addTo(Calendar) method, which may work incorrectly with Duration objects with very large values in its fields. See the addTo(Calendar) method for details.

Parameters

startInstant:Calendar

The length of a month/year varies. The startInstant is used to disambiguate this variance. Specifically, this method returns the difference between startInstant and startInstant+duration

Returns:long

milliseconds between startInstant and startInstant plus this Duration

Exceptions

NullPointerException:

if startInstant parameter is null.

Returns the length of the duration in milli-seconds.

If the seconds field carries more digits than milli-second order, those will be simply discarded (or in other words, rounded to zero.) For example, for any Date value x,

new Duration("PT10.00099S").getTimeInMills(x) == 10000
new Duration("-PT10.00099S").getTimeInMills(x) == -10000

Note that this method uses the addTo(Date) method, which may work incorrectly with Duration objects with very large values in its fields. See the addTo(Date) method for details.

Parameters

startInstant:Date

The length of a month/year varies. The startInstant is used to disambiguate this variance. Specifically, this method returns the difference between startInstant and startInstant+duration.

Returns:long

milliseconds between startInstant and startInstant plus this Duration

Exceptions

NullPointerException:

If the startInstant parameter is null.

See Also

getTimeInMillis(Calendar)

Return the name of the XML Schema date/time type that this instance maps to. Type is computed based on fields that are set, i.e. isSet(DatatypeConstants.Field field) == true.

Returns:QName

one of the following constants: DatatypeConstants#DURATION, DatatypeConstants#DURATION_DAYTIME or DatatypeConstants#DURATION_YEARMONTH.

Exceptions

IllegalStateException:

If the combination of set fields does not match one of the XML Schema date/time datatypes.

Get the years value of this Duration as an int or 0 if not present.

getYears() is a convenience method for getField(DatatypeConstants.YEARS).

As the return value is an int, an incorrect value will be returned for Durations with years that go beyond the range of an int. Use getField(DatatypeConstants.YEARS) to avoid possible loss of precision.

Returns:int

If the years field is present, return its value as an int, else return 0.

Overrides java.lang.Object.hashCode.

Returns a hash code consistent with the definition of the equals method.

See Also

Object#hashCode()

Checks if this duration object is strictly longer than another Duration object.

Duration X is "longer" than Y if and only if X > Y as defined in the section 3.2.6.2 of the XML Schema 1.0 specification.

For example, "P1D" (one day) > "PT12H" (12 hours) and "P2Y" (two years) > "P23M" (23 months).

Parameters

duration:Duration

Duration to test this Duration against.

Returns:boolean

true if the duration represented by this object is longer than the given duration. false otherwise.

Exceptions

UnsupportedOperationException:

If the underlying implementation cannot reasonably process the request, e.g. W3C XML Schema allows for arbitrarily large/small/precise values, the request may be beyond the implementations capability.

NullPointerException:

If duration is null.

See Also

isShorterThan(Duration), compare(Duration duration)

Checks if a field is set. A field of a duration object may or may not be present. This method can be used to test if a field is present.

Parameters

field:DatatypeConstants.Field

one of the six Field constants (YEARS,MONTHS,DAYS,HOURS, MINUTES, or SECONDS.)

Returns:boolean

true if the field is present. false if not.

Exceptions

NullPointerException:

If the field parameter is null.

Checks if this duration object is strictly shorter than another Duration object.

Parameters

duration:Duration

Duration to test this Duration against.

Returns:boolean

true if duration parameter is shorter than this Duration, else false.

Exceptions

UnsupportedOperationException:

If the underlying implementation cannot reasonably process the request, e.g. W3C XML Schema allows for arbitrarily large/small/precise values, the request may be beyond the implementations capability.

NullPointerException:

if duration is null.

See Also

isLongerThan(Duration duration), compare(Duration duration)

Computes a new duration whose value is factor times longer than the value of this duration.

This method is provided for the convenience. It is functionally equivalent to the following code:

multiply(new BigDecimal(String.valueOf(factor)))

Parameters

factor:int

Factor times longer of new Duration to create.

Returns:Duration

New Duration that is factortimes longer than this Duration.

See Also

multiply(BigDecimal)

Computes a new duration whose value is factor times longer than the value of this duration.

For example,

"P1M" (1 month) * "12" = "P12M" (12 months)
"PT1M" (1 min) * "0.3" = "PT18S" (18 seconds)
"P1M" (1 month) * "1.5" = IllegalStateException

Since the Duration class is immutable, this method doesn't change the value of this object. It simply computes a new Duration object and returns it.

The operation will be performed field by field with the precision of BigDecimal. Since all the fields except seconds are restricted to hold integers, any fraction produced by the computation will be carried down toward the next lower unit. For example, if you multiply "P1D" (1 day) with "0.5", then it will be 0.5 day, which will be carried down to "PT12H" (12 hours). When fractions of month cannot be meaningfully carried down to days, or year to months, this will cause an IllegalStateException to be thrown. For example if you multiple one month by 0.5.

To avoid IllegalStateException, use the normalizeWith(Calendar) method to remove the years and months fields.

Parameters

factor:BigDecimal

to multiply by

Returns:Duration

returns a non-null valid Duration object

Exceptions

IllegalStateException:

if operation produces fraction in the months field.

NullPointerException:

if the factor parameter is null.

Returns a new Duration object whose value is -this.

Since the Duration class is immutable, this method doesn't change the value of this object. It simply computes a new Duration object and returns it.

Returns:Duration

always return a non-null valid Duration object.

Converts the years and months fields into the days field by using a specific time instant as the reference point.

For example, duration of one month normalizes to 31 days given the start time instance "July 8th 2003, 17:40:32".

Formally, the computation is done as follows:

1. the given Calendar object is cloned
2. the years, months and days fields will be added to the Calendar object by using the Calendar#add(int, int) method
3. the difference between the two Calendars in computed in milliseconds and converted to days, if a remainder occurs due to Daylight Savings Time, it is discarded
4. the computed days, along with the hours, minutes and seconds fields of this duration object is used to construct a new Duration object.

Note that since the Calendar class uses int to hold the value of year and month, this method may produce an unexpected result if this duration object holds a very large value in the years or months fields.

Parameters

startTimeInstant:Calendar

Calendar reference point.

Returns:Duration

Duration of years and months of this Duration as days.

Exceptions

NullPointerException:

If the startTimeInstant parameter is null.

Computes a new duration whose value is this-rhs.

For example:

"1 day" - "-3 days" = "4 days"
"1 year" - "1 day" = IllegalStateException
"-(1 hour,50 minutes)" - "-20 minutes" = "-(1hours,30 minutes)"
"15 hours" - "-3 days" = "3 days and 15 hours"
"1 year" - "-1 day" = "1 year and 1 day"

Since there's no way to meaningfully subtract 1 day from 1 month, there are cases where the operation fails in IllegalStateException.

Formally the computation is defined as follows. First, we can assume that two Durations are both positive without losing generality. (i.e., (-X)-Y=-(X+Y), X-(-Y)=X+Y, (-X)-(-Y)=-(X-Y))

Then two durations are subtracted field by field. If the sign of any non-zero field F is different from the sign of the most significant field, 1 (if F is negative) or -1 (otherwise) will be borrowed from the next bigger unit of F.

This process is repeated until all the non-zero fields have the same sign.

If a borrow occurs in the days field (in other words, if the computation needs to borrow 1 or -1 month to compensate days), then the computation fails by throwing an IllegalStateException.

Parameters

rhs:Duration

Duration to subtract from this Duration.

Returns:Duration

New Duration created from subtracting rhs from this Duration.

Exceptions

IllegalStateException:

If two durations cannot be meaningfully subtracted. For example, subtracting one day from one month causes this exception.

NullPointerException:

If the rhs parameter is null.

See Also

add(Duration)

Overrides java.lang.Object.toString.

Returns a String representation of this Duration Object.

The result is formatted according to the XML Schema 1.0 spec and can be always parsed back later into the equivalent Duration Object by DatatypeFactory#newDuration(String lexicalRepresentation).

Formally, the following holds for any Duration Object x:

new Duration(x.toString()).equals(x)

Returns:String

A non-null valid String representation of this Duration.