Class Duration
 java.lang.Object

 javax.xml.datatype.Duration
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.
Order relationship
Duration objects only have partial order, where two values A and B maybe either:
 A<B (A is shorter than B)
 A>B (A is longer than B)
 A==B (A and B are of the same duration)
 A<>B (Comparison between A and B is indeterminate)
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.
Operations over Duration
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.
Range of allowed values
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
.
 Since:
 1.5
 See Also:
XMLGregorianCalendar.add(Duration)
Constructor Summary
Constructor  Description 

Duration()  Default noarg constructor. 
Method Summary
Modifier and Type  Method  Description 

abstract Duration  add(Duration rhs)  Computes a new duration whose value is 
abstract void  addTo(Calendar calendar)  Adds this duration to a 
void  addTo(Date date)  Adds this duration to a 
abstract int  compare(Duration duration)  Partial order relation comparison with this 
boolean  equals(Object duration)  Checks if this duration object has the same duration as another 
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 
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 
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  multiply(int factor)  Computes a new duration whose value is 
abstract Duration  multiply(BigDecimal factor)  Computes a new duration whose value is 
abstract Duration  negate()  Returns a new 
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 
String  toString()  Returns a 
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Constructor Detail
Duration
public Duration()
Default noarg constructor.
Note: Always use the DatatypeFactory
to construct an instance of Duration
. The constructor on this class cannot be guaranteed to produce an object with a consistent state and may be removed in the future.
Method Detail
getXMLSchemaType
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
.
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 
 Returns:
 one of the following constants:
DatatypeConstants.DURATION
,DatatypeConstants.DURATION_DAYTIME
orDatatypeConstants.DURATION_YEARMONTH
.  Throws:

IllegalStateException
 If the combination of set fields does not match one of the XML Schema date/time datatypes.
getSign
public abstract int getSign()
Returns the sign of this duration in 1,0, or 1.
 Returns:
 1 if this duration is negative, 0 if the duration is zero, and 1 if the duration is positive.
getYears
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.
 Returns:
 If the years field is present, return its value as an
int
, else return0
.
getMonths
public int getMonths()
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:
 Months of this
Duration
.
getDays
public int getDays()
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:
 Days of this
Duration
.
getHours
public int getHours()
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:
 Hours of this
Duration
.
getMinutes
public int getMinutes()
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:
 Minutes of this
Duration
.
getSeconds
public int getSeconds()
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:
 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)
getTimeInMillis
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.
 Parameters:

startInstant
 The length of a month/year varies. ThestartInstant
is used to disambiguate this variance. Specifically, this method returns the difference betweenstartInstant
andstartInstant+duration
 Returns:
 milliseconds between
startInstant
andstartInstant
plus thisDuration
 Throws:

NullPointerException
 ifstartInstant
parameter is null.
getTimeInMillis
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.
 Parameters:

startInstant
 The length of a month/year varies. ThestartInstant
is used to disambiguate this variance. Specifically, this method returns the difference betweenstartInstant
andstartInstant+duration
.  Returns:
 milliseconds between
startInstant
andstartInstant
plus thisDuration
 Throws:

NullPointerException
 If the startInstant parameter is null.  See Also:
getTimeInMillis(Calendar)
getField
public abstract Number getField(DatatypeConstants.Field field)
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 nonnegative integer. In case of seconds, the returned number may be a nonnegative decimal value.
 Parameters:

field
 one of the six Field constants (YEARS,MONTHS,DAYS,HOURS, MINUTES, or SECONDS.)  Returns:
 If the specified field is present, this method returns a nonnull nonnegative
Number
object that represents its value. If it is not present, return null. For YEARS, MONTHS, DAYS, HOURS, and MINUTES, this method returns aBigInteger
object. For SECONDS, this method returns aBigDecimal
.  Throws:

NullPointerException
 If thefield
isnull
.
isSet
public abstract boolean isSet(DatatypeConstants.Field field)
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
 one of the six Field constants (YEARS,MONTHS,DAYS,HOURS, MINUTES, or SECONDS.)  Returns:
 true if the field is present. false if not.
 Throws:

NullPointerException
 If the field parameter is null.
add
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.
 Parameters:

rhs
Duration
to add to thisDuration
 Returns:
 nonnull valid Duration object.
 Throws:

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)
addTo
public abstract void addTo(Calendar calendar)
Adds this duration to a 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.
 Parameters:

calendar
 A calendar object whose value will be modified.  Throws:

NullPointerException
 if the calendar parameter is null.
addTo
public void addTo(Date date)
Adds this duration to a 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.
 Parameters:

date
 A date object whose value will be modified.  Throws:

NullPointerException
 if the date parameter is null.
subtract
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
.
 Parameters:

rhs
Duration
to subtract from thisDuration
.  Returns:
 New
Duration
created from subtractingrhs
from thisDuration
.  Throws:

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)
multiply
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)))
 Parameters:

factor
 Factor times longer of newDuration
to create.  Returns:
 New
Duration
that isfactor
times longer than thisDuration
.  See Also:
multiply(BigDecimal)
multiply
public abstract Duration multiply(BigDecimal factor)
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
 to multiply by  Returns:
 returns a nonnull valid
Duration
object  Throws:

IllegalStateException
 if operation produces fraction in the months field. 
NullPointerException
 if thefactor
parameter isnull
.
negate
public abstract Duration negate()
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:
 always return a nonnull valid
Duration
object.
normalizeWith
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:
 the given Calendar object is cloned
 the years, months and days fields will be added to the
Calendar
object by using theCalendar.add(int,int)
method  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
 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
reference point.  Returns:

Duration
of years and months of thisDuration
as days.  Throws:

NullPointerException
 If the startTimeInstant parameter is null.
compare
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 thisDuration
is shorter thanduration
parameter 
DatatypeConstants.EQUAL
if thisDuration
is equal toduration
parameter 
DatatypeConstants.GREATER
if thisDuration
is longer thanduration
parameter 
DatatypeConstants.INDETERMINATE
if a conclusive partial order relation cannot be determined
 Parameters:

duration
 to compare  Returns:
 the relationship between
this Duration
andduration
parameter asDatatypeConstants.LESSER
,DatatypeConstants.EQUAL
,DatatypeConstants.GREATER
orDatatypeConstants.INDETERMINATE
.  Throws:

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
 ifduration
isnull
.  See Also:

isShorterThan(Duration)
,isLongerThan(Duration)
isLongerThan
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).
 Parameters:

duration
Duration
to test thisDuration
against.  Returns:
 true if the duration represented by this object is longer than the given duration. false otherwise.
 Throws:

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
 Ifduration
is null.  See Also:

isShorterThan(Duration)
,compare(Duration duration)
isShorterThan
public boolean isShorterThan(Duration duration)
Checks if this duration object is strictly shorter than another Duration
object.
 Parameters:

duration
Duration
to test thisDuration
against.  Returns:

true
ifduration
parameter is shorter than thisDuration
, elsefalse
.  Throws:

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
 ifduration
is null.  See Also:

isLongerThan(Duration duration)
,compare(Duration duration)
equals
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"))
 Overrides:

equals
in classObject
 Parameters:

duration
 The object to compare thisDuration
against.  Returns:

true
if this duration is the same length asduration
.false
ifduration
isnull
, is not aDuration
object, or its length is different from this duration.  Throws:

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)
hashCode
public abstract int hashCode()
Returns a hash code consistent with the definition of the equals method.
 Overrides:

hashCode
in classObject
 Returns:
 a hash code value for this object.
 See Also:
Object.hashCode()
toString
public String 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)