net.sf.saxon.value
Class DateValue

java.lang.Object
  extended by net.sf.saxon.value.Value
      extended by net.sf.saxon.value.AtomicValue
          extended by net.sf.saxon.value.CalendarValue
              extended by net.sf.saxon.value.GDateValue
                  extended by net.sf.saxon.value.DateValue
All Implemented Interfaces:
Serializable, Comparable, PullEvent, SequenceIterable, GroundedValue, Item, ValueRepresentation, ConversionResult

public class DateValue
extends GDateValue
implements Comparable

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

See Also:
Serialized Form

Field Summary
 
Fields inherited from class net.sf.saxon.value.CalendarValue
NO_TIMEZONE
 
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
 
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, toDateTime
 
Methods inherited from class net.sf.saxon.value.CalendarValue
adjustTimezone, appendTimezone, appendTimezone, getStringValue, getTimezoneInMinutes, getXPathComparable, hasTimezone, removeTimezone, setTimezoneInMinutes
 
Methods inherited from class net.sf.saxon.value.AtomicValue
asAtomic, checkPermittedContents, convert, convert, effectiveBooleanValue, getCardinality, getItemType, getLength, getTypedValue, getTypeLabel, isNaN, itemAt, iterate, process, setTypeLabel, subsequence, toString
 
Methods inherited from class net.sf.saxon.value.Value
asItem, asItem, asIterator, asValue, convertJavaObjectToXPath, convertToJava, fromItem, getIterator, iterate, makeQNameValue, reduce, stringToNumber
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

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.

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.

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.

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
Method Detail

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

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.

Specified by:
getPrimitiveType in class AtomicValue
Returns:
the primitive type

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

convertPrimitive

public ConversionResult convertPrimitive(BuiltInAtomicType requiredType,
                                         boolean validate,
                                         XPathContext context)
Convert to target data type

Parameters:
requiredType - an integer identifying the required atomic type
context - the XPath dynamic context
validate - true if validation is required. If set to false, the caller guarantees that the value is valid for the target data type, and that further validation is therefore not required. Note that a validation failure may be reported even if validation was not requested.
Returns:
an AtomicValue, a value of the required type; or an ErrorValue

getStringValueCS

public CharSequence getStringValueCS()
Convert to string

Specified by:
getStringValueCS in interface Item
Specified by:
getStringValueCS in interface ValueRepresentation
Overrides:
getStringValueCS in class AtomicValue
Returns:
ISO 8601 representation.
See Also:
Item.getStringValue()

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 class 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

copyAsSubType

public AtomicValue copyAsSubType(AtomicType typeLabel)
Make a copy of this date value, but with a new type label

Specified by:
copyAsSubType in class AtomicValue
Parameters:
typeLabel - the new type label: must be a subtype of xs:date
Returns:
the new xs:date value

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

Specified by:
adjustTimezone in class 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

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 class AtomicValue
Parameters:
component - identifies the required component, as a constant defined in class Component, for example Component.HOURS
Returns:
the value of the requested component of this value
Throws:
XPathException

add

public CalendarValue add(DurationValue duration)
                  throws XPathException
Add a duration to a date

Specified by:
add in class 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

subtract

public DayTimeDurationValue subtract(CalendarValue other,
                                     XPathContext context)
                              throws XPathException
Determine the difference between two points in time, as a duration

Overrides:
subtract in class 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

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.

Specified by:
compareTo in interface Comparable
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
Throws:
ClassCastException - if the values are not comparable (which might be because no timezone is available)

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

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

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

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

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


Copyright (C) Michael H. Kay. All rights reserved.