net.sf.saxon.value

Class DateValue

Implemented Interfaces:
Comparable, ConversionResult, GroundedValue, Item, PullEvent, Serializable, SequenceIterable, ValueRepresentation

public class DateValue
extends GDateValue
implements Comparable

A value of type Date. Note that a Date may include a TimeZone.

Field Summary

Fields inherited from class net.sf.saxon.value.GDateValue

day, daysPerMonth, month, monthData, year

Fields inherited from class net.sf.saxon.value.CalendarValue

NO_TIMEZONE

Fields inherited from class net.sf.saxon.value.AtomicValue

typeLabel

Fields inherited from class net.sf.saxon.value.Value

EMPTY_CLASS_ARRAY, INDETERMINATE_ORDERING

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Constructor Summary

DateValue(CharSequence s)
Constructor: create a date value from a supplied string, in ISO 8601 format
DateValue(GregorianCalendar calendar, int tz)
Create a DateValue
DateValue(int year, byte month, byte day)
Constructor given a year, month, and day.
DateValue(int year, byte month, byte day, int tz)
Constructor given a year, month, and day, and timezone.
DateValue(int year, byte month, byte day, int tz, AtomicType type)
Constructor given a year, month, and day, and timezone, and an AtomicType representing a subtype of xs:date.

Method Summary

CalendarValue
add(DurationValue duration)
Add a duration to a date
CalendarValue
adjustTimezone(int timezone)
Return a new date with the same normalized value, but in a different timezone.
int
compareTo(Object v2)
Context-free comparison of two DateValue values.
ConversionResult
convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context)
Convert to target data type
AtomicValue
copyAsSubType(AtomicType typeLabel)
Make a copy of this date value, but with a new type label
static DateValue
dateFromJulianDayNumber(int julianDayNumber)
Get the Gregorian date corresponding to a particular Julian day number.
CharSequence
getCanonicalLexicalRepresentation()
Get the canonical lexical representation as defined in XML Schema.
AtomicValue
getComponent(int component)
Get a component of the value.
static int
getDayOfWeek(int year, int month, int day)
Get the day of the week.
static int
getDayWithinYear(int year, int month, int day)
Get the ordinal day number within the year (1 Jan = 1, 1 Feb = 32, etc)
static int
getJulianDayNumber(int year, int month, int day)
Calculate the Julian day number at 00:00 on a given date.
BuiltInAtomicType
getPrimitiveType()
Determine the primitive type of the value.
CharSequence
getStringValueCS()
Convert to string
static int
getWeekNumber(int year, int month, int day)
Get the ISO week number for a given date.
static int
getWeekNumberWithinMonth(int year, int month, int day)
Get the week number within a month.
static ConversionResult
makeDateValue(CharSequence in)
Static factory method: construct a DateValue from a string in the lexical form of a date, returning a ValidationFailure if the supplied string is invalid
DayTimeDurationValue
subtract(CalendarValue other, XPathContext context)
Determine the difference between two points in time, as a duration
static DateValue
tomorrow(int year, byte month, byte day)
Get the date that immediately follows a given date
static DateValue
yesterday(int year, byte month, byte day)
Get the date that immediately precedes a given date

Methods inherited from class net.sf.saxon.value.GDateValue

compareTo, convertToJava, equals, getCalendar, getComparisonKey, getDay, getMonth, getSchemaComparable, getYear, hashCode, isLeapYear, isValidDate, setLexicalValue, toDateTime

Methods inherited from class net.sf.saxon.value.CalendarValue

add, adjustTimezone, adjustTimezone, appendTimezone, appendTimezone, compareTo, getCalendar, getComparisonKey, getStringValue, getTimezoneInMinutes, getXPathComparable, hasTimezone, removeTimezone, setTimezoneInMinutes, subtract, toDateTime

Methods inherited from class net.sf.saxon.value.AtomicValue

asAtomic, checkPermittedContents, convert, convert, convertPrimitive, copyAsSubType, effectiveBooleanValue, equals, getCardinality, getComponent, getItemType, getLength, getPrimitiveType, getSchemaComparable, getStringValue, getStringValueCS, getTypeLabel, getTypedValue, getXPathComparable, isNaN, itemAt, iterate, process, setTypeLabel, subsequence, toString

Methods inherited from class net.sf.saxon.value.Value

asItem, asItem, asIterator, asValue, checkPermittedContents, convertJavaObjectToXPath, convertToJava, convertToJava, effectiveBooleanValue, equals, fromItem, getCanonicalLexicalRepresentation, getCardinality, getItemType, getIterator, getLength, getSchemaComparable, getStringValue, getStringValueCS, itemAt, iterate, iterate, makeQNameValue, process, reduce, stringToNumber, toString

Constructor Details

DateValue

public DateValue(CharSequence s)
            throws ValidationException
Constructor: create a date value from a supplied string, in ISO 8601 format
Parameters:
s - the lexical form of the date value
Throws:
ValidationException - if the supplied string is not a valid date

DateValue

public DateValue(GregorianCalendar calendar,
                 int tz)
Create a DateValue
Parameters:
calendar - the absolute date/time value
tz - The timezone offset from GMT in minutes, positive or negative; or the special value NO_TIMEZONE indicating that the value is not in a timezone

DateValue

public DateValue(int year,
                 byte month,
                 byte day)
Constructor given a year, month, and day. Performs no validation.
Parameters:
year - The year as held internally (note that the year before 1AD is 0)
month - The month, 1-12
day - The day 1-31

DateValue

public DateValue(int year,
                 byte month,
                 byte day,
                 int tz)
Constructor given a year, month, and day, and timezone. Performs no validation.

DateValue

public DateValue(int year,
                 byte month,
                 byte day,
                 int tz,
                 AtomicType type)
Constructor given a year, month, and day, and timezone, and an AtomicType representing a subtype of xs:date. Performs no validation.
Parameters:
year - The year as held internally (note that the year before 1AD is 0)
month - The month, 1-12
day - The day 1-31
tz - the timezone displacement in minutes from UTC. Supply the value CalendarValue.NO_TIMEZONE if there is no timezone component.
type - the type. This must be a type derived from xs:date, and the value must conform to this type. The method does not check these conditions.

Method Details

add

public CalendarValue add(DurationValue duration)
            throws XPathException
Add a duration to a date
Overrides:
add in interface CalendarValue
Parameters:
duration - the duration to be added (may be negative)
Returns:
the new date
Throws:
XPathException - if the duration is an xs:duration, as distinct from a subclass thereof

adjustTimezone

public CalendarValue adjustTimezone(int timezone)
Return a new date with the same normalized value, but in a different timezone. This is called only for a DateValue that has an explicit timezone
Overrides:
adjustTimezone in interface CalendarValue
Parameters:
timezone - the new timezone offset, in minutes
Returns:
the time in the new timezone. This will be a new TimeValue unless no change was required to the original value

compareTo

public int compareTo(Object v2)
Context-free comparison of two DateValue values. For this to work, the two values must either both have a timezone or both have none.
Parameters:
v2 - the other value
Returns:
the result of the comparison: -1 if the first is earlier, 0 if they are equal, +1 if the first is later

convertPrimitive

public ConversionResult convertPrimitive(BuiltInAtomicType requiredType,
                                         boolean validate,
                                         XPathContext context)
Convert to target data type
Overrides:
convertPrimitive in interface AtomicValue
Parameters:
requiredType - an integer identifying the required atomic type
context - the XPath dynamic context
Returns:
an AtomicValue, a value of the required type; or an ErrorValue

copyAsSubType

public AtomicValue copyAsSubType(AtomicType typeLabel)
Make a copy of this date value, but with a new type label
Overrides:
copyAsSubType in interface AtomicValue
Parameters:
typeLabel - the new type label: must be a subtype of xs:date
Returns:
the new xs:date value

dateFromJulianDayNumber

public static DateValue dateFromJulianDayNumber(int julianDayNumber)
Get the Gregorian date corresponding to a particular Julian day number. The algorithm is taken from http://www.hermetic.ch/cal_stud/jdn.htm#comp
Parameters:
julianDayNumber - the Julian day number
Returns:
a DateValue with no timezone information set

getCanonicalLexicalRepresentation

public CharSequence getCanonicalLexicalRepresentation()
Get the canonical lexical representation as defined in XML Schema. This is not always the same as the result of casting to a string according to the XPath rules. For xs:date, the timezone is adjusted to be in the range +12:00 to -11:59
Overrides:
getCanonicalLexicalRepresentation in interface Value
Returns:
the canonical lexical representation if defined in XML Schema; otherwise, the result of casting to string according to the XPath 2.0 rules

getComponent

public AtomicValue getComponent(int component)
            throws XPathException
Get a component of the value. Returns null if the timezone component is requested and is not present.
Overrides:
getComponent in interface AtomicValue

getDayOfWeek

public static int getDayOfWeek(int year,
                               int month,
                               int day)
Get the day of the week. The days of the week are numbered from 1 (Monday) to 7 (Sunday)
Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
the day of the week, 1=Monday .... 7=Sunday

getDayWithinYear

public static int getDayWithinYear(int year,
                                   int month,
                                   int day)
Get the ordinal day number within the year (1 Jan = 1, 1 Feb = 32, etc)
Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
the ordinal day number within the year

getJulianDayNumber

public static int getJulianDayNumber(int year,
                                     int month,
                                     int day)
Calculate the Julian day number at 00:00 on a given date. This algorithm is taken from http://vsg.cape.com/~pbaum/date/jdalg.htm and http://vsg.cape.com/~pbaum/date/jdalg2.htm (adjusted to handle BC dates correctly)

Note that this assumes dates in the proleptic Gregorian calendar

Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
the Julian day number

getPrimitiveType

public BuiltInAtomicType getPrimitiveType()
Determine the primitive type of the value. This delivers the same answer as getItemType().getPrimitiveItemType(). The primitive types are the 19 primitive types of XML Schema, plus xs:integer, xs:dayTimeDuration and xs:yearMonthDuration, and xs:untypedAtomic. For external objects, the result is AnyAtomicType.
Overrides:
getPrimitiveType in interface AtomicValue

getStringValueCS

public CharSequence getStringValueCS()
Convert to string
Specified by:
getStringValueCS in interface Item
getStringValueCS in interface ValueRepresentation
Overrides:
getStringValueCS in interface AtomicValue
Returns:
ISO 8601 representation.

getWeekNumber

public static int getWeekNumber(int year,
                                int month,
                                int day)
Get the ISO week number for a given date. The days of the week are numbered from 1 (Monday) to 7 (Sunday), and week 1 in any calendar year is the week (from Monday to Sunday) that includes the first Thursday of that year
Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
the ISO week number

getWeekNumberWithinMonth

public static int getWeekNumberWithinMonth(int year,
                                           int month,
                                           int day)
Get the week number within a month. This is required for the XSLT format-date() function, and the rules are not entirely clear. The days of the week are numbered from 1 (Monday) to 7 (Sunday), and by analogy with the ISO week number, we consider that week 1 in any calendar month is the week (from Monday to Sunday) that includes the first Thursday of that month. Unlike the ISO week number, we put the previous days in week zero.
Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
the week number within a month

makeDateValue

public static ConversionResult makeDateValue(CharSequence in)
Static factory method: construct a DateValue from a string in the lexical form of a date, returning a ValidationFailure if the supplied string is invalid
Parameters:
in - the lexical form of the date
Returns:
either a DateValue or a ValidationFailure

subtract

public DayTimeDurationValue subtract(CalendarValue other,
                                     XPathContext context)
            throws XPathException
Determine the difference between two points in time, as a duration
Overrides:
subtract in interface CalendarValue
Parameters:
other - the other point in time
context - the XPath dynamic context
Returns:
the duration as an xs:dayTimeDuration
Throws:
XPathException - for example if one value is a date and the other is a time

tomorrow

public static DateValue tomorrow(int year,
                                 byte month,
                                 byte day)
Get the date that immediately follows a given date
Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
a new DateValue with no timezone information

yesterday

public static DateValue yesterday(int year,
                                  byte month,
                                  byte day)
Get the date that immediately precedes a given date
Parameters:
year - the year
month - the month (1-12)
day - the day (1-31)
Returns:
a new DateValue with no timezone information