net.sf.saxon.value
Class DateValue

java.lang.Object
  net.sf.saxon.value.Value
      net.sf.saxon.value.AtomicValue
          net.sf.saxon.value.CalendarValue
              net.sf.saxon.value.DateValue

All Implemented Interfaces:

java.lang.Comparable, Expression, Item, java.io.Serializable, 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:

Serialized Form

Field Summary

protected byte	day
protected byte	month
protected int	year

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

NO_TIMEZONE

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

EMPTY_CLASS_ARRAY

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

EMPTY_VALUE_ARRAY

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

protected	DateValue() Default constructor needed for subtyping
	DateValue(java.lang.CharSequence s) Constructor: create a dateTime value from a supplied string, in ISO 8601 format
	DateValue(java.util.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.

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(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.
int	compareTo(java.lang.Object other) Compare the value to another date value.
AtomicValue	convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context) Convert to target data type
java.lang.Object	convertToJava(java.lang.Class target, XPathContext context) Convert to Java object (for passing to external functions)
CalendarValue	copy() Make a copy of this date, time, or dateTime value
static DateValue	dateFromJulianDayNumber(int julianDayNumber) Get the Gregorian date corresponding to a particular Julian day number.
boolean	equals(java.lang.Object other) Compare two (sequence) values for equality.
java.util.GregorianCalendar	getCalendar() Get a Java Calendar object that represents this date/time value.
AtomicValue	getComponent(int component) Get a component of the value.
byte	getDay() Get the day component of the date (in local form)
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)
ItemType	getItemType(TypeHierarchy th) Determine the data type of the expression
static int	getJulianDayNumber(int year, int month, int day) Calculate the Julian day number at 00:00 on a given date.
byte	getMonth() Get the month component of the date (in local form)
java.lang.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.
int	getYear() Get the year component of the date (in local form)
int	hashCode() Return a hash code to support the equals() function
static boolean	isLeapYear(int year) Test whether a year is a leap year
static boolean	isValidDate(int year, int month, int day)
static void	main(java.lang.String[] args) Temporary test rig
void	setLexicalValue(java.lang.CharSequence s) Initialize the DateValue using a character string in the format yyyy-mm-dd and an optional time zone.
SecondsDurationValue	subtract(CalendarValue other, XPathContext context) Determine the difference between two points in time, as a duration
DateTimeValue	toDateTime() Convert to DateTime
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.CalendarValue

appendTimezone, appendTimezone, getStringValue, getTimezoneInMinutes, hasTimezone, removeTimezone, setTimezoneInMinutes

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

checkPermittedContents, convert, convert, display, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getImplementationMethod, getLength, getPrimitiveValue, getTypedValue, hasBuiltInType, iterate, process, schemaEquals, toString

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

asItem, asIterator, asValue, collapseWhitespace, convert, convertJavaObjectToXPath, getDependencies, getIterator, getParentExpression, getSpecialProperties, itemAt, iterateSubExpressions, makeQNameValue, normalizeWhitespace, optimize, promote, reduce, simplify, stringToNumber, trimWhitespace, typeCheck

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

year

protected int year

month

protected byte month

day

protected byte day

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(java.lang.CharSequence s)
          throws XPathException

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

DateValue

public DateValue(java.util.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

setLexicalValue

public void setLexicalValue(java.lang.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

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

toDateTime

public DateTimeValue toDateTime()

Convert to DateTime

Specified by:

toDateTime in class CalendarValue

getStringValueCS

public java.lang.CharSequence getStringValueCS()

Convert to string

Specified by:

getStringValueCS in interface Item

Overrides:

getStringValueCS in class AtomicValue

Returns:

ISO 8601 representation.

getCalendar

public java.util.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 java.lang.Object convertToJava(java.lang.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(java.lang.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:

java.lang.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.

Specified by:

compareTo in class CalendarValue

equals

public boolean equals(java.lang.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(java.lang.String[] args)
                 throws java.lang.Exception

Temporary test rig

Throws:

java.lang.Exception