Back to index...

	/*
	* Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	* Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* * Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	*
	* * Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	*
	* * Neither the name of JSR-310 nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	package java.time.chrono;

	import static java.time.temporal.ChronoField.DAY_OF_MONTH;
	import static java.time.temporal.ChronoField.DAY_OF_YEAR;
	import static java.time.temporal.ChronoField.ERA;
	import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
	import static java.time.temporal.ChronoField.YEAR;
	import static java.time.temporal.ChronoField.YEAR_OF_ERA;
	import static java.time.temporal.ChronoUnit.DAYS;
	import static java.time.temporal.ChronoUnit.MONTHS;

	import java.io.InvalidObjectException;
	import java.io.ObjectInputStream;
	import java.io.Serializable;
	import java.time.Clock;
	import java.time.DateTimeException;
	import java.time.Instant;
	import java.time.LocalDate;
	import java.time.Year;
	import java.time.ZoneId;
	import java.time.format.ResolverStyle;
	import java.time.temporal.ChronoField;
	import java.time.temporal.TemporalAccessor;
	import java.time.temporal.TemporalAdjusters;
	import java.time.temporal.TemporalField;
	import java.time.temporal.UnsupportedTemporalTypeException;
	import java.time.temporal.ValueRange;
	import java.util.Calendar;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;

	import sun.util.calendar.CalendarSystem;
	import sun.util.calendar.LocalGregorianCalendar;

	/**
	* The Japanese Imperial calendar system.
	* <p>
	* This chronology defines the rules of the Japanese Imperial calendar system.
	* This calendar system is primarily used in Japan.
	* The Japanese Imperial calendar system is the same as the ISO calendar system
	* apart from the era-based year numbering.
	* <p>
	* Japan introduced the Gregorian calendar starting with Meiji 6.
	* Only Meiji and later eras are supported;
	* dates before Meiji 6, January 1 are not supported.
	* <p>
	* The supported {@code ChronoField} instances are:
	* <ul>
	* <li>{@code DAY_OF_WEEK}
	* <li>{@code DAY_OF_MONTH}
	* <li>{@code DAY_OF_YEAR}
	* <li>{@code EPOCH_DAY}
	* <li>{@code MONTH_OF_YEAR}
	* <li>{@code PROLEPTIC_MONTH}
	* <li>{@code YEAR_OF_ERA}
	* <li>{@code YEAR}
	* <li>{@code ERA}
	* </ul>
	*
	* @implSpec
	* This class is immutable and thread-safe.
	*
	* @since 1.8
	*/
	public final class JapaneseChronology extends AbstractChronology implements Serializable {

	static final LocalGregorianCalendar JCAL =
	(LocalGregorianCalendar) CalendarSystem.forName("japanese");

	// Locale for creating a JapaneseImpericalCalendar.
	static final Locale LOCALE = Locale.forLanguageTag("ja-JP-u-ca-japanese");

	/**
	* Singleton instance for Japanese chronology.
	*/
	public static final JapaneseChronology INSTANCE = new JapaneseChronology();

	/**
	* Serialization version.
	*/
	@java.io.Serial
	private static final long serialVersionUID = 459996390165777884L;

	//-----------------------------------------------------------------------
	/**
	* Restricted constructor.
	*/
	private JapaneseChronology() {
	}

	//-----------------------------------------------------------------------
	/**
	* Gets the ID of the chronology - 'Japanese'.
	* <p>
	* The ID uniquely identifies the {@code Chronology}.
	* It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
	*
	* @return the chronology ID - 'Japanese'
	* @see #getCalendarType()
	*/
	@Override
	public String getId() {
	return "Japanese";
	}

	/**
	* Gets the calendar type of the underlying calendar system - 'japanese'.
	* <p>
	* The calendar type is an identifier defined by the
	* <em>Unicode Locale Data Markup Language (LDML)</em> specification.
	* It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
	* It can also be used as part of a locale, accessible via
	* {@link Locale#getUnicodeLocaleType(String)} with the key 'ca'.
	*
	* @return the calendar system type - 'japanese'
	* @see #getId()
	*/
	@Override
	public String getCalendarType() {
	return "japanese";
	}

	//-----------------------------------------------------------------------
	/**
	* Obtains a local date in Japanese calendar system from the
	* era, year-of-era, month-of-year and day-of-month fields.
	* <p>
	* The Japanese month and day-of-month are the same as those in the
	* ISO calendar system. They are not reset when the era changes.
	* For example:
	* <pre>
	* 6th Jan Showa 64 = ISO 1989-01-06
	* 7th Jan Showa 64 = ISO 1989-01-07
	* 8th Jan Heisei 1 = ISO 1989-01-08
	* 9th Jan Heisei 1 = ISO 1989-01-09
	* </pre>
	*
	* @param era the Japanese era, not null
	* @param yearOfEra the year-of-era
	* @param month the month-of-year
	* @param dayOfMonth the day-of-month
	* @return the Japanese local date, not null
	* @throws DateTimeException if unable to create the date
	* @throws ClassCastException if the {@code era} is not a {@code JapaneseEra}
	*/
	@Override
	public JapaneseDate date(Era era, int yearOfEra, int month, int dayOfMonth) {
	if (!(era instanceof JapaneseEra jera)) {
	throw new ClassCastException("Era must be JapaneseEra");
	}
	return JapaneseDate.of(jera, yearOfEra, month, dayOfMonth);
	}

	/**
	* Obtains a local date in Japanese calendar system from the
	* proleptic-year, month-of-year and day-of-month fields.
	* <p>
	* The Japanese proleptic year, month and day-of-month are the same as those
	* in the ISO calendar system. They are not reset when the era changes.
	*
	* @param prolepticYear the proleptic-year
	* @param month the month-of-year
	* @param dayOfMonth the day-of-month
	* @return the Japanese local date, not null
	* @throws DateTimeException if unable to create the date
	*/
	@Override
	public JapaneseDate date(int prolepticYear, int month, int dayOfMonth) {
	return new JapaneseDate(LocalDate.of(prolepticYear, month, dayOfMonth));
	}

	/**
	* Obtains a local date in Japanese calendar system from the
	* era, year-of-era and day-of-year fields.
	* <p>
	* The day-of-year in this factory is expressed relative to the start of the year-of-era.
	* This definition changes the normal meaning of day-of-year only in those years
	* where the year-of-era is reset to one due to a change in the era.
	* For example:
	* <pre>
	* 6th Jan Showa 64 = day-of-year 6
	* 7th Jan Showa 64 = day-of-year 7
	* 8th Jan Heisei 1 = day-of-year 1
	* 9th Jan Heisei 1 = day-of-year 2
	* </pre>
	*
	* @param era the Japanese era, not null
	* @param yearOfEra the year-of-era
	* @param dayOfYear the day-of-year
	* @return the Japanese local date, not null
	* @throws DateTimeException if unable to create the date
	* @throws ClassCastException if the {@code era} is not a {@code JapaneseEra}
	*/
	@Override
	public JapaneseDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {
	return JapaneseDate.ofYearDay((JapaneseEra) era, yearOfEra, dayOfYear);
	}

	/**
	* Obtains a local date in Japanese calendar system from the
	* proleptic-year and day-of-year fields.
	* <p>
	* The day-of-year in this factory is expressed relative to the start of the proleptic year.
	* The Japanese proleptic year and day-of-year are the same as those in the ISO calendar system.
	* They are not reset when the era changes.
	*
	* @param prolepticYear the proleptic-year
	* @param dayOfYear the day-of-year
	* @return the Japanese local date, not null
	* @throws DateTimeException if unable to create the date
	*/
	@Override
	public JapaneseDate dateYearDay(int prolepticYear, int dayOfYear) {
	return new JapaneseDate(LocalDate.ofYearDay(prolepticYear, dayOfYear));
	}

	/**
	* Obtains a local date in the Japanese calendar system from the epoch-day.
	*
	* @param epochDay the epoch day
	* @return the Japanese local date, not null
	* @throws DateTimeException if unable to create the date
	*/
	@Override // override with covariant return type
	public JapaneseDate dateEpochDay(long epochDay) {
	return new JapaneseDate(LocalDate.ofEpochDay(epochDay));
	}

	@Override
	public JapaneseDate dateNow() {
	return dateNow(Clock.systemDefaultZone());
	}

	@Override
	public JapaneseDate dateNow(ZoneId zone) {
	return dateNow(Clock.system(zone));
	}

	@Override
	public JapaneseDate dateNow(Clock clock) {
	return date(LocalDate.now(clock));
	}

	@Override
	public JapaneseDate date(TemporalAccessor temporal) {
	if (temporal instanceof JapaneseDate) {
	return (JapaneseDate) temporal;
	}
	return new JapaneseDate(LocalDate.from(temporal));
	}

	@Override
	@SuppressWarnings("unchecked")
	public ChronoLocalDateTime<JapaneseDate> localDateTime(TemporalAccessor temporal) {
	return (ChronoLocalDateTime<JapaneseDate>)super.localDateTime(temporal);
	}

	@Override
	@SuppressWarnings("unchecked")
	public ChronoZonedDateTime<JapaneseDate> zonedDateTime(TemporalAccessor temporal) {
	return (ChronoZonedDateTime<JapaneseDate>)super.zonedDateTime(temporal);
	}

	@Override
	@SuppressWarnings("unchecked")
	public ChronoZonedDateTime<JapaneseDate> zonedDateTime(Instant instant, ZoneId zone) {
	return (ChronoZonedDateTime<JapaneseDate>)super.zonedDateTime(instant, zone);
	}

	//-----------------------------------------------------------------------
	/**
	* Checks if the specified year is a leap year.
	* <p>
	* Japanese calendar leap years occur exactly in line with ISO leap years.
	* This method does not validate the year passed in, and only has a
	* well-defined result for years in the supported range.
	*
	* @param prolepticYear the proleptic-year to check, not validated for range
	* @return true if the year is a leap year
	*/
	@Override
	public boolean isLeapYear(long prolepticYear) {
	return IsoChronology.INSTANCE.isLeapYear(prolepticYear);
	}

	@Override
	public int prolepticYear(Era era, int yearOfEra) {
	if (era instanceof JapaneseEra == false) {
	throw new ClassCastException("Era must be JapaneseEra");
	}

	JapaneseEra jera = (JapaneseEra) era;
	int gregorianYear = jera.getPrivateEra().getSinceDate().getYear() + yearOfEra - 1;
	if (yearOfEra == 1) {
	return gregorianYear;
	}
	if (gregorianYear >= Year.MIN_VALUE && gregorianYear <= Year.MAX_VALUE) {
	LocalGregorianCalendar.Date jdate = JCAL.newCalendarDate(null);
	jdate.setEra(jera.getPrivateEra()).setDate(yearOfEra, 1, 1);
	if (JapaneseChronology.JCAL.validate(jdate)) {
	return gregorianYear;
	}
	}
	throw new DateTimeException("Invalid yearOfEra value");
	}

	/**
	* Returns the calendar system era object from the given numeric value.
	*
	* The numeric values supported by this method are the same as the
	* numeric values supported by {@link JapaneseEra#of(int)}.
	*
	* @param eraValue the era value
	* @return the Japanese {@code Era} for the given numeric era value
	* @throws DateTimeException if {@code eraValue} is invalid
	*/
	@Override
	public JapaneseEra eraOf(int eraValue) {
	return JapaneseEra.of(eraValue);
	}

	@Override
	public List<Era> eras() {
	return List.of(JapaneseEra.values());
	}

	JapaneseEra getCurrentEra() {
	// Assume that the last JapaneseEra is the current one.
	JapaneseEra[] eras = JapaneseEra.values();
	return eras[eras.length - 1];
	}

	//-----------------------------------------------------------------------
	@Override
	public ValueRange range(ChronoField field) {
	switch (field) {
	case ALIGNED_DAY_OF_WEEK_IN_MONTH:
	case ALIGNED_DAY_OF_WEEK_IN_YEAR:
	case ALIGNED_WEEK_OF_MONTH:
	case ALIGNED_WEEK_OF_YEAR:
	throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
	case YEAR_OF_ERA: {
	Calendar jcal = Calendar.getInstance(LOCALE);
	int startYear = getCurrentEra().getPrivateEra().getSinceDate().getYear();
	return ValueRange.of(1, jcal.getGreatestMinimum(Calendar.YEAR),
	jcal.getLeastMaximum(Calendar.YEAR) + 1, // +1 due to the different definitions
	Year.MAX_VALUE - startYear);
	}
	case DAY_OF_YEAR: {
	Calendar jcal = Calendar.getInstance(LOCALE);
	int fieldIndex = Calendar.DAY_OF_YEAR;
	return ValueRange.of(jcal.getMinimum(fieldIndex), jcal.getGreatestMinimum(fieldIndex),
	jcal.getLeastMaximum(fieldIndex), jcal.getMaximum(fieldIndex));
	}
	case YEAR:
	return ValueRange.of(JapaneseDate.MEIJI_6_ISODATE.getYear(), Year.MAX_VALUE);
	case ERA:
	return ValueRange.of(JapaneseEra.MEIJI.getValue(), getCurrentEra().getValue());
	default:
	return field.range();
	}
	}

	//-----------------------------------------------------------------------
	@Override // override for return type
	public JapaneseDate resolveDate(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
	return (JapaneseDate) super.resolveDate(fieldValues, resolverStyle);
	}

	@Override // override for special Japanese behavior
	ChronoLocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
	// validate era and year-of-era
	Long eraLong = fieldValues.get(ERA);
	JapaneseEra era = null;
	if (eraLong != null) {
	era = eraOf(range(ERA).checkValidIntValue(eraLong, ERA)); // always validated
	}
	Long yoeLong = fieldValues.get(YEAR_OF_ERA);
	int yoe = 0;
	if (yoeLong != null) {
	yoe = range(YEAR_OF_ERA).checkValidIntValue(yoeLong, YEAR_OF_ERA); // always validated
	}
	// if only year-of-era and no year then invent era unless strict
	if (era == null && yoeLong != null && fieldValues.containsKey(YEAR) == false && resolverStyle != ResolverStyle.STRICT) {
	era = JapaneseEra.values()[JapaneseEra.values().length - 1];
	}
	// if both present, then try to create date
	if (yoeLong != null && era != null) {
	if (fieldValues.containsKey(MONTH_OF_YEAR)) {
	if (fieldValues.containsKey(DAY_OF_MONTH)) {
	return resolveYMD(era, yoe, fieldValues, resolverStyle);
	}
	}
	if (fieldValues.containsKey(DAY_OF_YEAR)) {
	return resolveYD(era, yoe, fieldValues, resolverStyle);
	}
	}
	return null;
	}

	private int prolepticYearLenient(JapaneseEra era, int yearOfEra) {
	return era.getPrivateEra().getSinceDate().getYear() + yearOfEra - 1;
	}

	private ChronoLocalDate resolveYMD(JapaneseEra era, int yoe, Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle) {
	fieldValues.remove(ERA);
	fieldValues.remove(YEAR_OF_ERA);
	if (resolverStyle == ResolverStyle.LENIENT) {
	int y = prolepticYearLenient(era, yoe);
	long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
	long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
	return date(y, 1, 1).plus(months, MONTHS).plus(days, DAYS);
	}
	int moy = range(MONTH_OF_YEAR).checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
	int dom = range(DAY_OF_MONTH).checkValidIntValue(fieldValues.remove(DAY_OF_MONTH), DAY_OF_MONTH);
	if (resolverStyle == ResolverStyle.SMART) { // previous valid
	if (yoe < 1) {
	throw new DateTimeException("Invalid YearOfEra: " + yoe);
	}
	int y = prolepticYearLenient(era, yoe);
	JapaneseDate result;
	try {
	result = date(y, moy, dom);
	} catch (DateTimeException ex) {
	result = date(y, moy, 1).with(TemporalAdjusters.lastDayOfMonth());
	}
	// handle the era being changed
	// only allow if the new date is in the same Jan-Dec as the era change
	// determine by ensuring either original yoe or result yoe is 1
	if (result.getEra() != era && result.get(YEAR_OF_ERA) > 1 && yoe > 1) {
	throw new DateTimeException("Invalid YearOfEra for Era: " + era + " " + yoe);
	}
	return result;
	}
	return date(era, yoe, moy, dom);
	}

	private ChronoLocalDate resolveYD(JapaneseEra era, int yoe, Map <TemporalField,Long> fieldValues, ResolverStyle resolverStyle) {
	fieldValues.remove(ERA);
	fieldValues.remove(YEAR_OF_ERA);
	if (resolverStyle == ResolverStyle.LENIENT) {
	int y = prolepticYearLenient(era, yoe);
	long days = Math.subtractExact(fieldValues.remove(DAY_OF_YEAR), 1);
	return dateYearDay(y, 1).plus(days, DAYS);
	}
	int doy = range(DAY_OF_YEAR).checkValidIntValue(fieldValues.remove(DAY_OF_YEAR), DAY_OF_YEAR);
	return dateYearDay(era, yoe, doy); // smart is same as strict
	}

	//-----------------------------------------------------------------------
	/**
	* Writes the Chronology using a
	* <a href="{@docRoot}/serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
	* @serialData
	* <pre>
	* out.writeByte(1); // identifies a Chronology
	* out.writeUTF(getId());
	* </pre>
	*
	* @return the instance of {@code Ser}, not null
	*/
	@Override
	@java.io.Serial
	Object writeReplace() {
	return super.writeReplace();
	}

	/**
	* Defend against malicious streams.
	*
	* @param s the stream to read
	* @throws InvalidObjectException always
	*/
	@java.io.Serial
	private void readObject(ObjectInputStream s) throws InvalidObjectException {
	throw new InvalidObjectException("Deserialization via serialization delegate");
	}
	}

Back to index...