public abstract class Duration extends Object
Immutable representation of a time span as defined in the W3C XML Schema 1.0 specification.
A Duration object represents a period of Gregorian time, which consists of six fields (years, months, days, hours, minutes, and seconds) plus a sign (+/) field.
The first five fields have nonnegative (>=0) integers or null (which represents that the field is not set), and the seconds field has a nonnegative decimal or null. A negative sign indicates a negative duration.
This class provides a number of methods that make it easy to use for the duration datatype of XML Schema 1.0 with the errata.
Duration objects only have partial order, where two values A and B maybe either:
For example, 30 days cannot be meaningfully compared to one month.
The compare(Duration duration)
method implements this
relationship.
See the isLongerThan(Duration)
method for details about
the order relationship among Duration
objects.
This class provides a set of basic arithmetic operations, such as addition, subtraction and multiplication. Because durations don't have total order, an operation could fail for some combinations of operations. For example, you cannot subtract 15 days from 1 month. See the javadoc of those methods for detailed conditions where this could happen.
Also, division of a duration by a number is not provided because
the Duration
class can only deal with finite precision
decimal numbers. For example, one cannot represent 1 sec divided by 3.
However, you could substitute a division by 3 with multiplying by numbers such as 0.3 or 0.333.
Because some operations of Duration
rely on Calendar
even though Duration
can hold very large or very small values,
some of the methods may not work correctly on such Duration
s.
The impacted methods document their dependency on Calendar
.
XMLGregorianCalendar.add(Duration)
Constructor and Description 

Duration() 
Modifier and Type  Method and Description 

abstract Duration 
add(Duration rhs)
Computes a new duration whose value is
this+rhs . 
abstract void 
addTo(Calendar calendar)
Adds this duration to a
Calendar object. 
void 
addTo(Date date)
Adds this duration to a
Date object. 
abstract int 
compare(Duration duration)
Partial order relation comparison with this
Duration instance. 
boolean 
equals(Object duration)
Checks if this duration object has the same duration
as another
Duration object. 
int 
getDays()
Obtains the value of the DAYS field as an integer value,
or 0 if not present.

abstract Number 
getField(DatatypeConstants.Field field)
Gets the value of a field.

int 
getHours()
Obtains the value of the HOURS field as an integer value,
or 0 if not present.

int 
getMinutes()
Obtains the value of the MINUTES field as an integer value,
or 0 if not present.

int 
getMonths()
Obtains the value of the MONTHS field as an integer value,
or 0 if not present.

int 
getSeconds()
Obtains the value of the SECONDS field as an integer value,
or 0 if not present.

abstract int 
getSign()
Returns the sign of this duration in 1,0, or 1.

long 
getTimeInMillis(Calendar startInstant)
Returns the length of the duration in milliseconds.

long 
getTimeInMillis(Date startInstant)
Returns the length of the duration in milliseconds.

QName 
getXMLSchemaType()
Return the name of the XML Schema date/time type that this instance
maps to.

int 
getYears()
Get the years value of this
Duration as an int or 0 if not present. 
abstract int 
hashCode()
Returns a hash code consistent with the definition of the equals method.

boolean 
isLongerThan(Duration duration)
Checks if this duration object is strictly longer than
another
Duration object. 
abstract boolean 
isSet(DatatypeConstants.Field field)
Checks if a field is set.

boolean 
isShorterThan(Duration duration)
Checks if this duration object is strictly shorter than
another
Duration object. 
abstract Duration 
multiply(BigDecimal factor)
Computes a new duration whose value is
factor times
longer than the value of this duration. 
Duration 
multiply(int factor)
Computes a new duration whose value is
factor times
longer than the value of this duration. 
abstract Duration 
negate()
Returns a new
Duration object whose
value is this . 
abstract Duration 
normalizeWith(Calendar startTimeInstant)
Converts the years and months fields into the days field
by using a specific time instant as the reference point.

Duration 
subtract(Duration rhs)
Computes a new duration whose value is
thisrhs . 
String 
toString()
Returns a
String representation of this Duration Object . 
public QName getXMLSchemaType()
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
.
Required fields for XML Schema 1.0 Date/Time Datatypes. (timezone is optional for all date/time datatypes) 


Datatype  year  month  day  hour  minute  second 
DatatypeConstants.DURATION 
X  X  X  X  X  X 
DatatypeConstants.DURATION_DAYTIME 
X  X  X  X  
DatatypeConstants.DURATION_YEARMONTH 
X  X 
DatatypeConstants.DURATION
,
DatatypeConstants.DURATION_DAYTIME
or
DatatypeConstants.DURATION_YEARMONTH
.IllegalStateException
 If the combination of set fields does not match one of the XML Schema date/time datatypes.public abstract int getSign()
public int getYears()
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 Duration
s
with years that go beyond the range of an int
.
Use getField(DatatypeConstants.YEARS)
to avoid possible loss of precision.
int
, else return 0
.public int getMonths()
getYears()
except
that this method works on the MONTHS field.Duration
.public int getDays()
getYears()
except
that this method works on the DAYS field.Duration
.public int getHours()
getYears()
except
that this method works on the HOURS field.Duration
.public int getMinutes()
getYears()
except
that this method works on the MINUTES field.Duration
.public int getSeconds()
getYears()
except
that this method works on the SECONDS field.public long getTimeInMillis(Calendar startInstant)
Returns the length of the duration in milliseconds.
If the seconds field carries more digits than millisecond 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.
startInstant
 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
startInstant
and
startInstant
plus this Duration
NullPointerException
 if startInstant
parameter
is null.public long getTimeInMillis(Date startInstant)
Returns the length of the duration in milliseconds.
If the seconds field carries more digits than millisecond 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.
startInstant
 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
.startInstant
and
startInstant
plus this Duration
NullPointerException
 If the startInstant parameter is null.getTimeInMillis(Calendar)
public abstract Number getField(DatatypeConstants.Field field)
Number
object.
In case of YEARS, MONTHS, DAYS, HOURS, and MINUTES, the returned
number will be a nonnegative integer. In case of seconds,
the returned number may be a nonnegative decimal value.field
 one of the six Field constants (YEARS,MONTHS,DAYS,HOURS,
MINUTES, or SECONDS.)Number
object that
represents its value. If it is not present, return null.
For YEARS, MONTHS, DAYS, HOURS, and MINUTES, this method
returns a BigInteger
object. For SECONDS, this
method returns a BigDecimal
.NullPointerException
 If the field
is null
.public abstract boolean isSet(DatatypeConstants.Field field)
field
 one of the six Field constants (YEARS,MONTHS,DAYS,HOURS,
MINUTES, or SECONDS.)NullPointerException
 If the field parameter is null.public abstract Duration add(Duration rhs)
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 Duration
s to be added
are both positive without losing generality (i.e.,
(X)+Y=YX
, X+(Y)=XY
,
(X)+(Y)=(X+Y)
)
Addition of two positive Duration
s 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 Duration
s are unset.
Note that lhs.add(rhs)
will be always successful if
lhs.signum()*rhs.signum()!=1
or both of them are
normalized.
rhs
 Duration
to add to this Duration
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.subtract(Duration)
public abstract void addTo(Calendar calendar)
Calendar
object.
Calls 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.
calendar
 A calendar object whose value will be modified.NullPointerException
 if the calendar parameter is null.public void addTo(Date date)
Date
object.
The given date is first converted into
a 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.
date
 A date object whose value will be modified.NullPointerException
 if the date parameter is null.public Duration subtract(Duration rhs)
Computes a new duration whose value is thisrhs
.
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 Duration
s are both positive
without losing generality. (i.e.,
(X)Y=(X+Y)
, X(Y)=X+Y
,
(X)(Y)=(XY)
)
Then two durations are subtracted field by field. If the sign of any nonzero 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 nonzero 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
.
rhs
 Duration
to subtract from this Duration
.Duration
created from subtracting rhs
from this Duration
.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.add(Duration)
public Duration multiply(int factor)
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)))
factor
 Factor times longer of new Duration
to create.Duration
that is factor
times longer than this Duration
.multiply(BigDecimal)
public abstract Duration multiply(BigDecimal factor)
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.
factor
 to multiply byDuration
objectIllegalStateException
 if operation produces fraction in
the months field.NullPointerException
 if the factor
parameter is
null
.public abstract Duration negate()
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.
Duration
object.public abstract Duration normalizeWith(Calendar startTimeInstant)
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:
Calendar
object
by using the Calendar.add(int,int)
methodNote 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.
startTimeInstant
 Calendar
reference point.Duration
of years and months of this Duration
as days.NullPointerException
 If the startTimeInstant parameter is null.public abstract int compare(Duration duration)
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
parameterDatatypeConstants.EQUAL
if this Duration
is equal to duration
parameterDatatypeConstants.GREATER
if this Duration
is longer than duration
parameterDatatypeConstants.INDETERMINATE
if a conclusive partial order relation cannot be determinedduration
 to comparethis
Duration
and duration
parameter as
DatatypeConstants.LESSER
, DatatypeConstants.EQUAL
, DatatypeConstants.GREATER
or DatatypeConstants.INDETERMINATE
.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
.isShorterThan(Duration)
,
isLongerThan(Duration)
public boolean isLongerThan(Duration duration)
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).
duration
 Duration
to test this Duration
against.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.isShorterThan(Duration)
,
compare(Duration duration)
public boolean isShorterThan(Duration duration)
Checks if this duration object is strictly shorter than
another Duration
object.
duration
 Duration
to test this Duration
against.true
if duration
parameter is shorter than this Duration
,
else false
.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.isLongerThan(Duration duration)
,
compare(Duration duration)
public boolean equals(Object duration)
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 Duration
s 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"))
equals
in class Object
duration
 A nonnull valid Duration
object.true
if this duration is the same length as
duration
.
false
if duration
is not a
Duration
object, is null
,
or its length is different from this duration.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.compare(Duration duration)
public abstract int hashCode()
hashCode
in class Object
Object.hashCode()
public String toString()
Returns a String
representation of this Duration
Object
.
The result is formatted according to the XML Schema 1.0 specification 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)