net.sf.saxon.value.DateValue Maven / Gradle / Ivy
package net.sf.saxon.value;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.functions.Component;
import net.sf.saxon.om.FastStringBuffer;
import net.sf.saxon.om.StandardNames;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.*;
import java.util.Calendar;
import java.util.GregorianCalendar;
/**
* A value of type Date. Note that a Date may include a TimeZone.
*/
public class DateValue extends GDateValue implements Comparable {
/**
* Private constructor of a skeletal DateValue
*/
private DateValue(){}
/**
* Constructor given a year, month, and day. Performs no validation.
* @param year The year as held internally (note that the year before 1AD is 0)
* @param month The month, 1-12
* @param day The day 1-31
*/
public DateValue(int year, byte month, byte day) {
this.year = year;
this.month = month;
this.day = day;
typeLabel = BuiltInAtomicType.DATE;
}
/**
* Constructor given a year, month, and day, and timezone. Performs no validation.
* @param year The year as held internally (note that the year before 1AD is 0)
* @param month The month, 1-12
* @param day The day 1-31
* @param tz the timezone displacement in minutes from UTC. Supply the value
* {@link CalendarValue#NO_TIMEZONE} if there is no timezone component.
*/
public DateValue(int year, byte month, byte day, int tz) {
this.year = year;
this.month = month;
this.day = day;
setTimezoneInMinutes(tz);
typeLabel = BuiltInAtomicType.DATE;
}
/**
* Constructor given a year, month, and day, and timezone, and an AtomicType representing
* a subtype of xs:date. Performs no validation.
* @param year The year as held internally (note that the year before 1AD is 0)
* @param month The month, 1-12
* @param day The day 1-31
* @param tz the timezone displacement in minutes from UTC. Supply the value
* {@link CalendarValue#NO_TIMEZONE} if there is no timezone component.
* @param 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.
*/
public DateValue(int year, byte month, byte day, int tz, AtomicType type) {
this.year = year;
this.month = month;
this.day = day;
setTimezoneInMinutes(tz);
typeLabel = type;
}
/**
* Constructor: create a date value from a supplied string, in
* ISO 8601 format
* @param s the lexical form of the date value
* @throws ValidationException if the supplied string is not a valid date
*/
public DateValue(CharSequence s) throws ValidationException {
setLexicalValue(this, s).asAtomic();
typeLabel = BuiltInAtomicType.DATE;
}
/**
* Create a DateValue
* @param calendar the absolute date/time value
* @param 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
*/
public DateValue(GregorianCalendar calendar, int tz) {
// Note: this constructor is not used by Saxon itself, but might be used by applications
int era = calendar.get(GregorianCalendar.ERA);
year = calendar.get(Calendar.YEAR);
if (era == GregorianCalendar.BC) {
year = 1-year;
}
month = (byte)(calendar.get(Calendar.MONTH)+1);
day = (byte)(calendar.get(Calendar.DATE));
setTimezoneInMinutes(tz);
typeLabel = BuiltInAtomicType.DATE;
}
/**
* 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
* @param in the lexical form of the date
* @return either a DateValue or a ValidationFailure
*/
public static ConversionResult makeDateValue(CharSequence in) {
DateValue d = new DateValue();
d.typeLabel = BuiltInAtomicType.DATE;
return setLexicalValue(d, in);
}
/**
* 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.
*/
public BuiltInAtomicType getPrimitiveType() {
return BuiltInAtomicType.DATE;
}
/**
* Get the date that immediately follows a given date
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return a new DateValue with no timezone information
*/
public static DateValue tomorrow(int year, byte month, byte day) {
if (DateValue.isValidDate(year, month, day+1)) {
return new DateValue(year, month, (byte)(day+1));
} else if (month < 12) {
return new DateValue(year, (byte)(month+1), (byte)1);
} else {
return new DateValue(year+1, (byte)1, (byte)1);
}
}
/**
* Get the date that immediately precedes a given date
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return a new DateValue with no timezone information
*/
public static DateValue yesterday(int year, byte month, byte day) {
if (day > 1) {
return new DateValue(year, month, (byte)(day-1));
} else if (month > 1) {
if (month == 3 && isLeapYear(year)) {
return new DateValue(year, (byte)2, (byte)29);
} else {
return new DateValue(year, (byte)(month-1), daysPerMonth[month-2]);
}
} else {
return new DateValue(year-1, (byte)12, (byte)31);
}
}
/**
* Convert to target data type
* @param requiredType an integer identifying the required atomic type
* @param context the XPath dynamic context
* @return an AtomicValue, a value of the required type; or an ErrorValue
*/
public ConversionResult convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context) {
switch(requiredType.getPrimitiveType()) {
case StandardNames.XS_DATE:
case StandardNames.XS_ANY_ATOMIC_TYPE:
return this;
case StandardNames.XS_DATE_TIME:
return toDateTime();
case StandardNames.XS_STRING:
return new StringValue(getStringValueCS());
case StandardNames.XS_UNTYPED_ATOMIC:
return new UntypedAtomicValue(getStringValueCS());
case StandardNames.XS_G_YEAR: {
return new GYearValue(year, getTimezoneInMinutes());
}
case StandardNames.XS_G_YEAR_MONTH: {
return new GYearMonthValue(year, month, getTimezoneInMinutes());
}
case StandardNames.XS_G_MONTH: {
return new GMonthValue(month, getTimezoneInMinutes());
}
case StandardNames.XS_G_MONTH_DAY: {
return new GMonthDayValue(month, day, getTimezoneInMinutes());
}
case StandardNames.XS_G_DAY:{
return new GDayValue(day, getTimezoneInMinutes());
}
default:
ValidationFailure err = new ValidationFailure("Cannot convert date to " +
requiredType.getDisplayName());
err.setErrorCode("XPTY0004");
return err;
}
}
/**
* Convert to string
* @return ISO 8601 representation.
*/
public CharSequence getStringValueCS() {
FastStringBuffer sb = new FastStringBuffer(16);
int yr = year;
if (year <= 0) {
sb.append('-');
yr = -yr +1; // no year zero in lexical space
}
appendString(sb, yr, (yr>9999 ? (yr+"").length() : 4));
sb.append('-');
appendTwoDigits(sb, month);
sb.append('-');
appendTwoDigits(sb, day);
if (hasTimezone()) {
appendTimezone(sb);
}
return sb;
}
/**
* 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
*
* @return the canonical lexical representation if defined in XML Schema; otherwise, the result
* of casting to string according to the XPath 2.0 rules
*/
public CharSequence getCanonicalLexicalRepresentation() {
DateValue target = this;
if (hasTimezone()) {
if (getTimezoneInMinutes() > 12*60) {
target = (DateValue)adjustTimezone(getTimezoneInMinutes() - 24*60);
} else if (getTimezoneInMinutes() <= -12*60) {
target = (DateValue)adjustTimezone(getTimezoneInMinutes() + 24*60);
}
}
return target.getStringValueCS();
}
/**
* Make a copy of this date value, but with a new type label
* @param typeLabel the new type label: must be a subtype of xs:date
* @return the new xs:date value
*/
public AtomicValue copyAsSubType(AtomicType typeLabel) {
DateValue v = new DateValue(year, month, day, getTimezoneInMinutes());
v.typeLabel = typeLabel;
return v;
}
/**
* 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
* @param timezone the new timezone offset, in minutes
* @return the time in the new timezone. This will be a new TimeValue unless no change
* was required to the original value
*/
public CalendarValue adjustTimezone(int timezone) {
DateTimeValue dt = (DateTimeValue)toDateTime().adjustTimezone(timezone);
return new DateValue(dt.getYear(), dt.getMonth(), dt.getDay(), dt.getTimezoneInMinutes());
}
/**
* Get a component of the value. Returns null if the timezone component is
* requested and is not present.
*/
public AtomicValue getComponent(int component) throws XPathException {
switch (component) {
case Component.YEAR_ALLOWING_ZERO:
return Int64Value.makeIntegerValue(year);
case Component.YEAR:
return Int64Value.makeIntegerValue(year > 0 ? year : year-1);
case Component.MONTH:
return Int64Value.makeIntegerValue(month);
case Component.DAY:
return Int64Value.makeIntegerValue(day);
case Component.TIMEZONE:
if (hasTimezone()) {
return DayTimeDurationValue.fromMilliseconds(getTimezoneInMinutes()*60000);
} else {
return null;
}
default:
throw new IllegalArgumentException("Unknown component for date: " + component);
}
}
/**
* Add a duration to a date
* @param duration the duration to be added (may be negative)
* @return the new date
* @throws net.sf.saxon.trans.XPathException if the duration is an xs:duration, as distinct from
* a subclass thereof
*/
public CalendarValue add(DurationValue duration) throws XPathException {
if (duration instanceof DayTimeDurationValue) {
long microseconds = ((DayTimeDurationValue)duration).getLengthInMicroseconds();
boolean negative = (microseconds < 0);
microseconds = Math.abs(microseconds);
int days = (int)Math.floor((double)microseconds / (1000000L*60L*60L*24L));
boolean partDay = (microseconds % (1000000L*60L*60L*24L)) > 0;
int julian = getJulianDayNumber(year, month, day);
DateValue d = dateFromJulianDayNumber(julian + (negative ? -days : days));
if (partDay) {
if (negative) {
d = yesterday(d.year, d.month, d.day);
}
}
d.setTimezoneInMinutes(getTimezoneInMinutes());
return d;
} else if (duration instanceof YearMonthDurationValue) {
int months = ((YearMonthDurationValue)duration).getLengthInMonths();
int m = (month-1) + months;
int y = year + m / 12;
m = m % 12;
if (m < 0) {
m += 12;
y -= 1;
}
m++;
int d = day;
while (!isValidDate(y, m, d)) {
d -= 1;
}
return new DateValue(y, (byte)m, (byte)d, getTimezoneInMinutes());
} else {
XPathException err = new XPathException("Date arithmetic is not supported on xs:duration, only on its subtypes");
err.setIsTypeError(true);
err.setErrorCode("XPTY0004");
throw err;
}
}
/**
* Determine the difference between two points in time, as a duration
* @param other the other point in time
* @param context the XPath dynamic context
* @return the duration as an xs:dayTimeDuration
* @throws XPathException for example if one value is a date and the other is a time
*/
public DayTimeDurationValue subtract(CalendarValue other, XPathContext context) throws XPathException {
if (!(other instanceof DateValue)) {
XPathException err = new XPathException("First operand of '-' is a date, but the second is not");
err.setIsTypeError(true);
err.setErrorCode("XPTY0004");
throw err;
}
return super.subtract(other, context);
}
/**
* Context-free comparison of two DateValue values. For this to work,
* the two values must either both have a timezone or both have none.
* @param v2 the other value
* @return 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)
*/
public int compareTo(Object v2) {
try {
return compareTo((DateValue)v2, null);
} catch (Exception err) {
throw new ClassCastException("DateTime comparison requires access to implicit timezone");
}
}
/**
* 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
*
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return the Julian day number
*/
public static int getJulianDayNumber(int year, int month, int day) {
int z = year - (month<3 ? 1 : 0);
short f = monthData[month-1];
if (z >= 0) {
return day + f + 365*z + z/4 - z/100 + z/400 + 1721118;
} else {
// for negative years, add 12000 years and then subtract the days!
z += 12000;
int j = day + f + 365*z + z/4 - z/100 + z/400 + 1721118;
return j - (365*12000 + 12000/4 - 12000/100 + 12000/400); // number of leap years in 12000 years
}
}
/**
* 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
* @param julianDayNumber the Julian day number
* @return a DateValue with no timezone information set
*/
public static DateValue dateFromJulianDayNumber(int julianDayNumber) {
if (julianDayNumber >= 0) {
int L = julianDayNumber + 68569 + 1; // +1 adjustment for days starting at noon
int n = ( 4 * L ) / 146097;
L = L - ( 146097 * n + 3 ) / 4;
int i = ( 4000 * ( L + 1 ) ) / 1461001;
L = L - ( 1461 * i ) / 4 + 31;
int j = ( 80 * L ) / 2447;
int d = L - ( 2447 * j ) / 80;
L = j / 11;
int m = j + 2 - ( 12 * L );
int y = 100 * ( n - 49 ) + i + L;
return new DateValue(y, (byte)m, (byte)d);
} else {
// add 12000 years and subtract them again...
DateValue dt = dateFromJulianDayNumber(julianDayNumber +
(365*12000 + 12000/4 - 12000/100 + 12000/400));
dt.year -= 12000;
return dt;
}
}
/**
* Get the ordinal day number within the year (1 Jan = 1, 1 Feb = 32, etc)
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return the ordinal day number within the year
*/
public static int getDayWithinYear(int year, int month, int day) {
int j = getJulianDayNumber(year, month, day);
int k = getJulianDayNumber(year, 1, 1);
return j - k + 1;
}
/**
* Get the day of the week. The days of the week are numbered from
* 1 (Monday) to 7 (Sunday)
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return the day of the week, 1=Monday .... 7=Sunday
*/
public static int getDayOfWeek(int year, int month, int day) {
int d = getJulianDayNumber(year, month, day);
d -= 2378500; // 1800-01-05 - any Monday would do
while (d <= 0) {
d += 70000000; // any sufficiently high multiple of 7 would do
}
return (d-1)%7 + 1;
}
/**
* 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
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return the ISO week number
*/
public static int getWeekNumber(int year, int month, int day) {
int d = getDayWithinYear(year, month, day);
int firstDay = getDayOfWeek(year, 1, 1);
if (firstDay > 4 && (firstDay + d) <= 8) {
// days before week one are part of the last week of the previous year (52 or 53)
return getWeekNumber(year-1, 12, 31);
}
int inc = (firstDay < 5 ? 1 : 0); // implements the First Thursday rule
return ((d + firstDay - 2) / 7) + inc;
}
/**
* 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.
* @param year the year
* @param month the month (1-12)
* @param day the day (1-31)
* @return the week number within a month
*/
public static int getWeekNumberWithinMonth(int year, int month, int day) {
int firstDay = getDayOfWeek(year, month, 1);
int inc = (firstDay < 5 ? 1 : 0); // implements the First Thursday rule
return ((day + firstDay - 2) / 7) + inc;
}
/**
* Temporary test rig
*/
// public static void main(String[] args) throws Exception {
// DateValue date = new DateValue(args[0]);
// System.out.println(date.getStringValue());
// int jd = getJulianDayNumber(date.year, date.month, date.day);
// System.out.println(jd);
// System.out.println(dateFromJulianDayNumber(jd).getStringValue());
// }
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//
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