net.sf.saxon.value

Class DateValue

public class DateValue extends CalendarValue

A value of type Date. Note that a Date may include a TimeZone.
Field Summary
protected byteday
protected bytemonth
protected intyear
Constructor Summary
protected DateValue()
Default constructor needed for subtyping
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(CharSequence s)
Constructor: create a dateTime value from a supplied string, in ISO 8601 format
DateValue(GregorianCalendar calendar, int tz)
Create a DateValue
Method Summary
CalendarValueadd(DurationValue duration)
Add a duration to a date
CalendarValueadjustTimezone(int timezone)
Return a new date with the same normalized value, but in a different timezone.
intcompareTo(Object other)
Compare the value to another date value.
intcompareTo(CalendarValue other, XPathContext context)
Compare this value to another value of the same type, using the supplied context object to get the implicit timezone if required.
AtomicValueconvertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context)
Convert to target data type
ObjectconvertToJava(Class target, XPathContext context)
Convert to Java object (for passing to external functions)
CalendarValuecopy()
Make a copy of this date, time, or dateTime value
static DateValuedateFromJulianDayNumber(int julianDayNumber)
Get the Gregorian date corresponding to a particular Julian day number.
booleanequals(Object other)
GregorianCalendargetCalendar()
AtomicValuegetComponent(int component)
Get a component of the value.
bytegetDay()
Get the day component of the date (in local form)
static intgetDayOfWeek(int year, int month, int day)
Get the day of the week.
static intgetDayWithinYear(int year, int month, int day)
Get the ordinal day number within the year (1 Jan = 1, 1 Feb = 32, etc)
ItemTypegetItemType(TypeHierarchy th)
Determine the data type of the expression
static intgetJulianDayNumber(int year, int month, int day)
Calculate the Julian day number at 00:00 on a given date.
bytegetMonth()
Get the month component of the date (in local form)
CharSequencegetStringValueCS()
Convert to string
static intgetWeekNumber(int year, int month, int day)
Get the ISO week number for a given date.
static intgetWeekNumberWithinMonth(int year, int month, int day)
Get the week number within a month.
intgetYear()
Get the year component of the date (in local form)
inthashCode()
static booleanisLeapYear(int year)
Test whether a year is a leap year
static booleanisValidDate(int year, int month, int day)
static voidmain(String[] args)
Temporary test rig
voidsetLexicalValue(CharSequence s)
Initialize the DateValue using a character string in the format yyyy-mm-dd and an optional time zone.
SecondsDurationValuesubtract(CalendarValue other, XPathContext context)
Determine the difference between two points in time, as a duration
DateTimeValuetoDateTime()
Convert to DateTime
static DateValuetomorrow(int year, byte month, byte day)
Get the date that immediately follows a given date
static DateValueyesterday(int year, byte month, byte day)
Get the date that immediately precedes a given date

Field Detail

day

protected byte day

month

protected byte month

year

protected int year

Constructor Detail

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)
Constructor: create a dateTime value from a supplied string, in ISO 8601 format

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

add

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

Parameters: duration the duration to be added (may be negative)

Returns: the new date

Throws: net.sf.saxon.trans.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

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 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, XPathContext context)
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.

convertPrimitive

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

Parameters: requiredType an integer identifying the required atomic type context

Returns: an AtomicValue, a value of the required type; or an ErrorValue

convertToJava

public Object convertToJava(Class target, XPathContext context)
Convert to Java object (for passing to external functions)

copy

public CalendarValue copy()
Make a copy of this date, time, or dateTime 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

Returns: a DateValue with no timezone information set

equals

public boolean equals(Object other)

getCalendar

public GregorianCalendar getCalendar()

getComponent

public AtomicValue getComponent(int component)
Get a component of the value. Returns null if the timezone component is requested and is not present.

getDay

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

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)

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)

getItemType

public ItemType getItemType(TypeHierarchy th)
Determine the data type of the expression

Parameters: th

Returns: Type.DATE_TYPE,

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)

getMonth

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

getStringValueCS

public CharSequence getStringValueCS()
Convert to string

Returns: ISO 8601 representation.

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.

getYear

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

hashCode

public int hashCode()

isLeapYear

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

isValidDate

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

main

public static void main(String[] args)
Temporary test rig

setLexicalValue

public void setLexicalValue(CharSequence s)
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: net.sf.saxon.trans.XPathException

subtract

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

Parameters: other the other point in time context

Returns: the duration as an xdt:dayTimeDuration

Throws: net.sf.saxon.trans.XPathException for example if one value is a date and the other is a time

toDateTime

public DateTimeValue toDateTime()
Convert to DateTime

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