Class 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:
  • Constructor Details

    • 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 Details

    • 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
      Specified by:
      convertPrimitive in class AtomicValue
      Parameters:
      requiredType - an integer identifying the required atomic type
      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.
      context - the XPath dynamic context
      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:
    • 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
    • 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