Class DateValue

All Implemented Interfaces:
Serializable, Comparable, Expression, Item, ValueRepresentation
Direct Known Subclasses:
GDayValue, GMonthDayValue, GMonthValue, GYearMonthValue, GYearValue

public class DateValue extends CalendarValue
A value of type Date. Note that a Date may include a TimeZone.
See Also:
  • Field Details

    • year

      protected int year
    • month

      protected byte month
    • day

      protected byte day
  • Constructor Details

    • DateValue

      protected DateValue()
      Default constructor needed for subtyping
    • 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(CharSequence s) throws XPathException
      Constructor: create a dateTime value from a supplied string, in ISO 8601 format
      Throws:
      XPathException
    • 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

    • setLexicalValue

      public void setLexicalValue(CharSequence s) throws XPathException
      Initialize the DateValue using a character string in the format yyyy-mm-dd and an optional time zone. Input must have format [-]yyyy-mm-dd[([+|-]hh:mm | Z)]
      Parameters:
      s - the supplied string value
      Throws:
      XPathException
    • getYear

      public int getYear()
      Get the year component of the date (in local form)
    • getMonth

      public byte getMonth()
      Get the month component of the date (in local form)
    • getDay

      public byte getDay()
      Get the day component of the date (in local form)
    • isValidDate

      public static boolean isValidDate(int year, int month, int day)
    • isLeapYear

      public static boolean isLeapYear(int year)
      Test whether a year is a leap year
    • tomorrow

      public static DateValue tomorrow(int year, byte month, byte day)
      Get the date that immediately follows a given date
      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
      Returns:
      a new DateValue with no timezone information
    • convertPrimitive

      public AtomicValue 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 -
      Returns:
      an AtomicValue, a value of the required type; or an ErrorValue
    • toDateTime

      public DateTimeValue toDateTime()
      Convert to DateTime
      Specified by:
      toDateTime in class CalendarValue
    • 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:
    • getCalendar

      public GregorianCalendar getCalendar()
      Description copied from class: CalendarValue
      Get a Java Calendar object that represents this date/time value. The Calendar object will be newly created for the purpose
      Specified by:
      getCalendar in class CalendarValue
      Returns:
      A Calendar object representing the date and time. Note that Java can only represent the time to millisecond precision, and that it does not support the full range of timezones required by XPath (-14:00 to +14:00)
    • getItemType

      public ItemType getItemType(TypeHierarchy th)
      Determine the data type of the expression
      Specified by:
      getItemType in interface Expression
      Overrides:
      getItemType in class Value
      Parameters:
      th -
      Returns:
      Type.DATE_TYPE,
    • copy

      public CalendarValue copy()
      Make a copy of this date, time, or dateTime value
      Specified by:
      copy in class CalendarValue
    • 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
    • convertToJava

      public Object convertToJava(Class target, XPathContext context) throws XPathException
      Convert to Java object (for passing to external functions)
      Overrides:
      convertToJava in class Value
      Throws:
      XPathException
    • 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
      Throws:
      XPathException
    • compareTo

      public int compareTo(Object other)
      Compare the value to another date value. This method is used only during schema processing, and uses XML Schema semantics rather than XPath semantics.
      Parameters:
      other - The other date value. Must be an object of class DateValue.
      Returns:
      negative value if this one is the earlier, 0 if they are chronologically equal, positive value if this one is the later. For this purpose, dateTime values with an unknown timezone are considered to be UTC values (the Comparable interface requires a total ordering).
      Throws:
      ClassCastException - if the other value is not a DateValue (the parameter is declared as Object to satisfy the Comparable interface)
    • compareTo

      public int compareTo(CalendarValue other, Configuration config)
      Compare this value to another value of the same type, using the supplied context object to get the implicit timezone if required. This method implements the XPath comparison semantics.
      Specified by:
      compareTo in class CalendarValue
    • getComparisonKey

      public ComparisonKey getComparisonKey(Configuration config)
      Get a comparison key for this value. Two values are equal if and only if they their comparison keys are equal
      Specified by:
      getComparisonKey in class CalendarValue
    • equals

      public boolean equals(Object other)
      Description copied from class: Value
      Compare two (sequence) values for equality. This supports identity constraints in XML Schema, which allow list-valued elements and attributes to participate in key and uniqueness constraints. This method returns false if any error occurs during the comparison, or if any of the items in either sequence is a node rather than an atomic value.
      Overrides:
      equals in class Value
    • hashCode

      public int hashCode()
      Description copied from class: Value
      Return a hash code to support the equals() function
      Overrides:
      hashCode in class 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 SecondsDurationValue 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 -
      Returns:
      the duration as an xdt:dayTimeDuration
      Throws:
      XPathException - for example if one value is a date and the other is a time
    • 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)
    • 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
      Returns:
      a DateValue with no timezone information set
    • getDayWithinYear

      public static final int getDayWithinYear(int year, int month, int day)
      Get the ordinal day number within the year (1 Jan = 1, 1 Feb = 32, etc)
    • getDayOfWeek

      public static final 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)
    • getWeekNumber

      public static final 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
    • getWeekNumberWithinMonth

      public static final 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.
    • main

      public static void main(String[] args) throws Exception
      Temporary test rig
      Throws:
      Exception