bp/chrono/JapaneseDate.java

/*
 * Copyright (c) 2007-present, 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,
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package org.threeten.bp.chrono;

import static org.threeten.bp.temporal.ChronoField.DAY_OF_MONTH;
import static org.threeten.bp.temporal.ChronoField.MONTH_OF_YEAR;
import static org.threeten.bp.temporal.ChronoField.YEAR;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Calendar;

import org.threeten.bp.Clock;
import org.threeten.bp.DateTimeException;
import org.threeten.bp.LocalDate;
import org.threeten.bp.LocalTime;
import org.threeten.bp.Period;
import org.threeten.bp.ZoneId;
import org.threeten.bp.jdk8.Jdk8Methods;
import org.threeten.bp.temporal.ChronoField;
import org.threeten.bp.temporal.TemporalAccessor;
import org.threeten.bp.temporal.TemporalAdjuster;
import org.threeten.bp.temporal.TemporalAmount;
import org.threeten.bp.temporal.TemporalField;
import org.threeten.bp.temporal.TemporalQuery;
import org.threeten.bp.temporal.TemporalUnit;
import org.threeten.bp.temporal.UnsupportedTemporalTypeException;
import org.threeten.bp.temporal.ValueRange;

/**
 * A date in the Japanese Imperial calendar system.
 * <p>
 * This date operates using the {@linkplain JapaneseChronology Japanese Imperial calendar}.
 * This calendar system is primarily used in Japan.
 * <p>
 * The Japanese Imperial calendar system is the same as the ISO calendar system
 * apart from the era-based year numbering. The proleptic-year is defined to be
 * equal to the ISO proleptic-year.
 * <p>
 * Japan introduced the Gregorian calendar starting with Meiji 6.
 * Only Meiji and later eras are supported.
 * <p>
 * For example, the Japanese year "Heisei 24" corresponds to ISO year "2012".<br>
 * Calling {@code japaneseDate.get(YEAR_OF_ERA)} will return 24.<br>
 * Calling {@code japaneseDate.get(YEAR)} will return 2012.<br>
 * Calling {@code japaneseDate.get(ERA)} will return 2, corresponding to
 * {@code JapaneseChEra.HEISEI}.<br>
 *
 * <h3>Specification for implementors</h3>
 * This class is immutable and thread-safe.
 */
public final class JapaneseDate
        extends ChronoDateImpl<JapaneseDate>
        implements Serializable {

    /**
     * Serialization version.
     */
    private static final long serialVersionUID = -305327627230580483L;
    /**
     * Minimum date.
     */
    static final LocalDate MIN_DATE = LocalDate.of(1873, 1, 1);

    /**
     * The underlying ISO local date.
     * @serial
     */
    private final LocalDate isoDate;
    /**
     * The JapaneseEra of this date.
     */
    private transient JapaneseEra era;
    /**
     * The Japanese imperial calendar year of this date.
     */
    private transient int yearOfEra;

    //-----------------------------------------------------------------------
    /**
     * Obtains the current {@code JapaneseDate} from the system clock in the default time-zone.
     * <p>
     * This will query the {@link Clock#systemDefaultZone() system clock} in the default
     * time-zone to obtain the current date.
     * <p>
     * Using this method will prevent the ability to use an alternate clock for testing
     * because the clock is hard-coded.
     *
     * @return the current date using the system clock and default time-zone, not null
     */
    public static JapaneseDate now() {
        return now(Clock.systemDefaultZone());
    }

    /**
     * Obtains the current {@code JapaneseDate} from the system clock in the specified time-zone.
     * <p>
     * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
     * Specifying the time-zone avoids dependence on the default time-zone.
     * <p>
     * Using this method will prevent the ability to use an alternate clock for testing
     * because the clock is hard-coded.
     *
     * @param zone  the zone ID to use, not null
     * @return the current date using the system clock, not null
     */
    public static JapaneseDate now(ZoneId zone) {
        return now(Clock.system(zone));
    }

    /**
     * Obtains the current {@code JapaneseDate} from the specified clock.
     * <p>
     * This will query the specified clock to obtain the current date - today.
     * Using this method allows the use of an alternate clock for testing.
     * The alternate clock may be introduced using {@linkplain Clock dependency injection}.
     *
     * @param clock  the clock to use, not null
     * @return the current date, not null
     * @throws DateTimeException if the current date cannot be obtained
     */
    public static JapaneseDate now(Clock clock) {
        return new JapaneseDate(LocalDate.now(clock));
    }

    /**
     * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
     * system from the era, year-of-era, month-of-year and day-of-month fields.
     * <p>
     * This returns a {@code JapaneseDate} with the specified fields.
     * The day must be valid for the year and month, otherwise an exception will be thrown.
     * <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 Japanese year-of-era
     * @param month  the Japanese month-of-year, from 1 to 12
     * @param dayOfMonth  the Japanese day-of-month, from 1 to 31
     * @return the date in Japanese calendar system, not null
     * @throws DateTimeException if the value of any field is out of range,
     *  or if the day-of-month is invalid for the month-year
     */
    public static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) {
        Jdk8Methods.requireNonNull(era, "era");
        if (yearOfEra < 1) {
            throw new DateTimeException("Invalid YearOfEra: " + yearOfEra);
        }
        LocalDate eraStartDate = era.startDate();
        LocalDate eraEndDate = era.endDate();
        int yearOffset = eraStartDate.getYear() - 1;
        LocalDate date = LocalDate.of(yearOfEra + yearOffset, month, dayOfMonth);
        if (date.isBefore(eraStartDate) || date.isAfter(eraEndDate)) {
            throw new DateTimeException("Requested date is outside bounds of era " + era);
        }
        return new JapaneseDate(era, yearOfEra, date);
    }

    /**
     * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
     * system from the era, year-of-era and day-of-year fields.
     * <p>
     * This returns a {@code JapaneseDate} with the specified fields.
     * The day must be valid for the year, otherwise an exception will be thrown.
     * The Japanese day-of-year is reset when the era changes.
     *
     * @param era  the Japanese era, not null
     * @param yearOfEra  the Japanese year-of-era
     * @param dayOfYear  the Japanese day-of-year, from 1 to 31
     * @return the date in Japanese calendar system, not null
     * @throws DateTimeException if the value of any field is out of range,
     *  or if the day-of-year is invalid for the year
     */
    static JapaneseDate ofYearDay(JapaneseEra era, int yearOfEra, int dayOfYear) {
        Jdk8Methods.requireNonNull(era, "era");
        if (yearOfEra < 1) {
            throw new DateTimeException("Invalid YearOfEra: " + yearOfEra);
        }
        LocalDate eraStartDate = era.startDate();
        LocalDate eraEndDate = era.endDate();
        if (yearOfEra == 1) {
            dayOfYear += eraStartDate.getDayOfYear() - 1;
            if (dayOfYear > eraStartDate.lengthOfYear()) {
                throw new DateTimeException("DayOfYear exceeds maximum allowed in the first year of era " + era);
            }
        }
        int yearOffset = eraStartDate.getYear() - 1;
        LocalDate isoDate = LocalDate.ofYearDay(yearOfEra + yearOffset, dayOfYear);
        if (isoDate.isBefore(eraStartDate) || isoDate.isAfter(eraEndDate)) {
            throw new DateTimeException("Requested date is outside bounds of era " + era);
        }
        return new JapaneseDate(era, yearOfEra, isoDate);
    }

    /**
     * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
     * system from the proleptic-year, month-of-year and day-of-month fields.
     * <p>
     * This returns a {@code JapaneseDate} with the specified fields.
     * The day must be valid for the year and month, otherwise an exception will be thrown.
     * <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 Japanese proleptic-year
     * @param month  the Japanese month-of-year, from 1 to 12
     * @param dayOfMonth  the Japanese day-of-month, from 1 to 31
     * @return the date in Japanese calendar system, not null
     * @throws DateTimeException if the value of any field is out of range,
     *  or if the day-of-month is invalid for the month-year
     */
    public static JapaneseDate of(int prolepticYear, int month, int dayOfMonth) {
        return new JapaneseDate(LocalDate.of(prolepticYear, month, dayOfMonth));
    }

    /**
     * Obtains a {@code JapaneseDate} from a temporal object.
     * <p>
     * This obtains a date in the Japanese calendar system based on the specified temporal.
     * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
     * which this factory converts to an instance of {@code JapaneseDate}.
     * <p>
     * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
     * field, which is standardized across calendar systems.
     * <p>
     * This method matches the signature of the functional interface {@link TemporalQuery}
     * allowing it to be used as a query via method reference, {@code JapaneseDate::from}.
     *
     * @param temporal  the temporal object to convert, not null
     * @return the date in Japanese calendar system, not null
     * @throws DateTimeException if unable to convert to a {@code JapaneseDate}
     */
    public static JapaneseDate from(TemporalAccessor temporal) {
        return JapaneseChronology.INSTANCE.date(temporal);
    }

    //-----------------------------------------------------------------------
    /**
     * Creates an instance from an ISO date.
     *
     * @param isoDate  the standard local date, validated not null
     */
    JapaneseDate(LocalDate isoDate) {
        if (isoDate.isBefore(MIN_DATE)) {
            throw new DateTimeException("Minimum supported date is January 1st Meiji 6");
        }
        this.era = JapaneseEra.from(isoDate);
        int yearOffset = this.era.startDate().getYear() - 1;
        this.yearOfEra = isoDate.getYear() - yearOffset;
        this.isoDate = isoDate;
    }

    /**
     * Constructs a {@code JapaneseDate}. This constructor does NOT validate the given parameters,
     * and {@code era} and {@code year} must agree with {@code isoDate}.
     *
     * @param era  the era, validated not null
     * @param year  the year-of-era, validated
     * @param isoDate  the standard local date, validated not null
     */
    JapaneseDate(JapaneseEra era, int year, LocalDate isoDate) {
        if (isoDate.isBefore(MIN_DATE)) {
            throw new DateTimeException("Minimum supported date is January 1st Meiji 6");
        }
        this.era = era;
        this.yearOfEra = year;
        this.isoDate = isoDate;
    }

    /**
     * Reconstitutes this object from a stream.
     *
     * @param stream object input stream
     */
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.era = JapaneseEra.from(isoDate);
        int yearOffset = this.era.startDate().getYear() - 1;
        this.yearOfEra = isoDate.getYear() - yearOffset;
    }

    //-----------------------------------------------------------------------
    @Override
    public JapaneseChronology getChronology() {
        return JapaneseChronology.INSTANCE;
    }

    @Override
    public JapaneseEra getEra() {
        return era;
    }

    @Override
    public int lengthOfMonth() {
        return isoDate.lengthOfMonth();
    }

    @Override
    public int lengthOfYear() {
        Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
        jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
        jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
        return  jcal.getActualMaximum(Calendar.DAY_OF_YEAR);
    }

    //-----------------------------------------------------------------------
    /**
     * Checks if the specified field is supported.
     * <p>
     * This checks if this date can be queried for the specified field.
     * If false, then calling the {@link #range(TemporalField) range} and
     * {@link #get(TemporalField) get} methods will throw an exception.
     * <p>
     * If the field is a {@link ChronoField} then the query is implemented here.
     * The supported fields 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>
     * All other {@code ChronoField} instances will return false.
     * <p>
     * If the field is not a {@code ChronoField}, then the result of this method
     * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
     * passing {@code this} as the argument.
     * Whether the field is supported is determined by the field.
     *
     * @param field  the field to check, null returns false
     * @return true if the field is supported on this date, false if not
     */
    @Override
    public boolean isSupported(TemporalField field) {
        if (field == ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH ||
                field == ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR ||
                field == ChronoField.ALIGNED_WEEK_OF_MONTH ||
                field == ChronoField.ALIGNED_WEEK_OF_YEAR) {
            return false;
        }
        return super.isSupported(field);
    }

    @Override
    public ValueRange range(TemporalField field) {
        if (field instanceof ChronoField) {
            if (isSupported(field)) {
                ChronoField f = (ChronoField) field;
                switch (f) {
                    case DAY_OF_YEAR:
                        return actualRange(Calendar.DAY_OF_YEAR);
                    case YEAR_OF_ERA:
                        return actualRange(Calendar.YEAR);
                }
                return getChronology().range(f);
            }
            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
        }
        return field.rangeRefinedBy(this);
    }

    private ValueRange actualRange(int calendarField) {
        Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
        jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
        jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
        return ValueRange.of(jcal.getActualMinimum(calendarField),
                                     jcal.getActualMaximum(calendarField));
    }

    @Override
    public long getLong(TemporalField field) {
        if (field instanceof ChronoField) {
            switch ((ChronoField) 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:
                    return yearOfEra;
                case ERA:
                    return era.getValue();
                case DAY_OF_YEAR:
                    return getDayOfYear();
            }
            return isoDate.getLong(field);
        }
        return field.getFrom(this);
    }

    private long getDayOfYear() {
        if (yearOfEra == 1) {
            return isoDate.getDayOfYear() - era.startDate().getDayOfYear() + 1;
        }
        return isoDate.getDayOfYear();
    }

    //-----------------------------------------------------------------------
    @Override
    public JapaneseDate with(TemporalAdjuster adjuster) {
        return (JapaneseDate) super.with(adjuster);
    }

    @Override
    public JapaneseDate with(TemporalField field, long newValue) {
        if (field instanceof ChronoField) {
            ChronoField f = (ChronoField) field;
            if (getLong(f) == newValue) {  // validates unsupported fields
                return this;
            }
            switch (f) {
                case DAY_OF_YEAR:
                case YEAR_OF_ERA:
                case ERA: {
                    int nvalue = getChronology().range(f).checkValidIntValue(newValue, f);
                    switch (f) {
                        case DAY_OF_YEAR:
                            return with(isoDate.plusDays(nvalue - getDayOfYear()));
                        case YEAR_OF_ERA:
                            return this.withYear(nvalue);
                        case ERA: {
                            return this.withYear(JapaneseEra.of(nvalue), yearOfEra);
                        }
                    }
                }
            }
            return with(isoDate.with(field, newValue));
        }
        return field.adjustInto(this, newValue);
    }

    @Override
    public JapaneseDate plus(TemporalAmount amount) {
        return (JapaneseDate) super.plus(amount);
    }

    @Override
    public JapaneseDate plus(long amountToAdd, TemporalUnit unit) {
        return (JapaneseDate) super.plus(amountToAdd, unit);
    }

    @Override
    public JapaneseDate minus(TemporalAmount amount) {
        return (JapaneseDate) super.minus(amount);
    }

    @Override
    public JapaneseDate minus(long amountToAdd, TemporalUnit unit) {
        return (JapaneseDate) super.minus(amountToAdd, unit);
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a copy of this date with the year altered.
     * <p>
     * This method changes the year of the date.
     * If the month-day is invalid for the year, then the previous valid day
     * will be selected instead.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param era  the era to set in the result, not null
     * @param yearOfEra  the year-of-era to set in the returned date
     * @return a {@code JapaneseDate} based on this date with the requested year, never null
     * @throws DateTimeException if {@code year} is invalid
     */
    private JapaneseDate withYear(JapaneseEra era, int yearOfEra) {
        int year = JapaneseChronology.INSTANCE.prolepticYear(era, yearOfEra);
        return with(isoDate.withYear(year));
    }

    /**
     * Returns a copy of this date with the year-of-era altered.
     * <p>
     * This method changes the year-of-era of the date.
     * If the month-day is invalid for the year, then the previous valid day
     * will be selected instead.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param year  the year to set in the returned date
     * @return a {@code JapaneseDate} based on this date with the requested year-of-era, never null
     * @throws DateTimeException if {@code year} is invalid
     */
    private JapaneseDate withYear(int year) {
        return withYear(getEra(), year);
    }

    //-----------------------------------------------------------------------
    @Override
    JapaneseDate plusYears(long years) {
        return with(isoDate.plusYears(years));
    }

    @Override
    JapaneseDate plusMonths(long months) {
        return with(isoDate.plusMonths(months));
    }

    @Override
    JapaneseDate plusDays(long days) {
        return with(isoDate.plusDays(days));
    }

    private JapaneseDate with(LocalDate newDate) {
        return (newDate.equals(isoDate) ? this : new JapaneseDate(newDate));
    }

    @Override
    @SuppressWarnings("unchecked")
    public final ChronoLocalDateTime<JapaneseDate> atTime(LocalTime localTime) {
        return (ChronoLocalDateTime<JapaneseDate>)super.atTime(localTime);
    }

    @Override
    public ChronoPeriod until(ChronoLocalDate endDate) {
        Period period = isoDate.until(endDate);
        return getChronology().period(period.getYears(), period.getMonths(), period.getDays());
    }

    @Override  // override for performance
    public long toEpochDay() {
        return isoDate.toEpochDay();
    }

    //-------------------------------------------------------------------------
    @Override  // override for performance
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof JapaneseDate) {
            JapaneseDate otherDate = (JapaneseDate) obj;
            return this.isoDate.equals(otherDate.isoDate);
        }
        return false;
    }

    @Override  // override for performance
    public int hashCode() {
        return getChronology().getId().hashCode() ^ isoDate.hashCode();
    }

    //-----------------------------------------------------------------------
    private Object writeReplace() {
        return new Ser(Ser.JAPANESE_DATE_TYPE, this);
    }

    void writeExternal(DataOutput out) throws IOException {
        // JapaneseChrono is implicit in the JAPANESE_DATE_TYPE
        out.writeInt(get(YEAR));
        out.writeByte(get(MONTH_OF_YEAR));
        out.writeByte(get(DAY_OF_MONTH));
    }

    static ChronoLocalDate readExternal(DataInput in) throws IOException {
        int year = in.readInt();
        int month = in.readByte();
        int dayOfMonth = in.readByte();
        return JapaneseChronology.INSTANCE.date(year, month, dayOfMonth);
    }


}