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/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* 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,
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package java.time.chrono;
import static java.time.chrono.JapaneseDate.MEIJI_6_ISODATE;
import static java.time.temporal.ChronoField.ERA;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;
import java.time.DateTimeException;
import java.time.LocalDate;
import java.time.Year;
import java.time.format.TextStyle;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalField;
import java.time.temporal.UnsupportedTemporalTypeException;
import java.time.temporal.ValueRange;
import java.util.Arrays;
import java.util.Locale;
import java.util.Objects;
/**
* An era in the Japanese Imperial calendar system.
* <p>
* The Japanese government defines the official name and start date of
* each era. Eras are consecutive and their date ranges do not overlap,
* so the end date of one era is always the day before the start date
* of the next era.
* <p>
* The Java SE Platform supports all eras defined by the Japanese government,
* beginning with the Meiji era. Each era is identified in the Platform by an
* integer value and a name. The {@link #of(int)} and {@link #valueOf(String)}
* methods may be used to obtain a singleton instance of JapaneseEra for each
* era. The {@link #values()} method returns the singleton instances of all
* supported eras.
* <p>
* For convenience, this class declares a number of public static final fields
* that refer to singleton instances returned by the values() method.
*
* @apiNote
* The fields declared in this class may evolve over time, in line with the
* results of the {@link #values()} method. However, there is not necessarily
* a 1:1 correspondence between the fields and the singleton instances.
*
* @apiNote
* The Japanese government may announce a new era and define its start
* date but not its official name. In this scenario, the singleton instance
* that represents the new era may return a name that is not stable until
* the official name is defined. Developers should exercise caution when
* relying on the name returned by any singleton instance that does not
* correspond to a public static final field.
*
* @implSpec
* This class is immutable and thread-safe.
*
* @since 1.8
*/
// For desugar: avoid dependencies on JDK-internal calendar helpers, which read a config file with
// era details. Hard-code era names and abbreviations found in the file, "calendars.properties".
public final class JapaneseEra
implements Era, Serializable {
// The offset value to 0-based index from the era value.
// i.e., getValue() + ERA_OFFSET == 0-based index
static final int ERA_OFFSET = 2;
// static final sun.util.calendar.Era[] ERA_CONFIG;
/**
* The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29)
* which has the value -1.
*/
// public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 1, 1));
public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 1, 1), "Meiji", "M");
/**
* The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
* which has the value 0.
*/
// public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30), "Taisho", "T");
/**
* The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
* which has the value 1.
*/
// public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25), "Showa", "S");
/**
* The singleton instance for the 'Heisei' era (1989-01-08 - 2019-04-30)
* which has the value 2.
*/
// public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8), "Heisei", "H");
/**
* The singleton instance for the 'Reiwa' era (2019-05-01 - current)
* which has the value 3. The end date of this era is not specified, unless
* the Japanese Government defines it.
*/
private static final JapaneseEra REIWA = new JapaneseEra(3, LocalDate.of(2019, 5, 1), "Reiwa", "R");
// The number of predefined JapaneseEra constants.
// There may be a supplemental era defined by the property.
private static final int N_ERA_CONSTANTS = REIWA.getValue() + ERA_OFFSET;
/**
* Serialization version.
*/
private static final long serialVersionUID = 1466499369062886794L;
// array for the singleton JapaneseEra instances
private static final JapaneseEra[] KNOWN_ERAS;
static {
// ERA_CONFIG = JapaneseChronology.JCAL.getEras();
// KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
KNOWN_ERAS = new JapaneseEra[N_ERA_CONSTANTS];
KNOWN_ERAS[0] = MEIJI;
KNOWN_ERAS[1] = TAISHO;
KNOWN_ERAS[2] = SHOWA;
KNOWN_ERAS[3] = HEISEI;
KNOWN_ERAS[4] = REIWA;
// for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
// CalendarDate date = ERA_CONFIG[i].getSinceDate();
// LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
// KNOWN_ERAS[i] = new JapaneseEra(i - ERA_OFFSET + 1, isoDate);
// }
};
// For desugar: moved here from JapaneseChronology for convenience and efficiency.
static JapaneseEra getCurrentEra() {
// Assume that the last JapaneseEra is the current one.
return KNOWN_ERAS[KNOWN_ERAS.length - 1];
}
// For desugar: use JapaneseEra instead of equivalent JDK-internal calendar helpers
/**
* Returns the number of years (rounded up) of the shortest {@code JapaneseEra} (i.e., the
* "minimum maximum" valid year). This method should return 15 for the 4 known eras.
*/
static long shortestYearsOfEra() {
int min = Year.MAX_VALUE - getCurrentEra().since.getYear() + 1;
int lastStartYear = KNOWN_ERAS[0].since.getYear();
for (int i = 1; i < KNOWN_ERAS.length; ++i) {
JapaneseEra era = KNOWN_ERAS[i];
int lastYearsOfEra = era.since.getYear() - lastStartYear + 1;
min = Math.min(min, lastYearsOfEra);
lastStartYear = era.since.getYear();
}
return min;
}
// For desugar: use JapaneseEra instead of equivalent JDK-internal calendar helpers
/**
* Returns the number of days in the shortest year of any {@code JapaneseEra} (i.e., the
* "minimum maximum" valid dayOfYear). This method should return 7 for the 4 known eras.
*/
static long shortestDaysOfYear() {
long min = ChronoField.DAY_OF_YEAR.range().getSmallestMaximum();
for (JapaneseEra era : KNOWN_ERAS) {
min = Math.min(min, era.since.lengthOfYear() - era.since.getDayOfYear() + 1);
if (era.next() != null) {
min = Math.min(min, era.next().since.getDayOfYear() - 1);
}
}
return min;
}
/**
* The era value.
* @serial
*/
private final transient int eraValue;
// the first day of the era
private final transient LocalDate since;
private final transient String name;
private final transient String abbreviation;
/**
* Creates an instance.
*
* @param eraValue the era value, validated
* @param since the date representing the first date of the era, validated not null
*/
// private JapaneseEra(int eraValue, LocalDate since) {
private JapaneseEra(int eraValue, LocalDate since, String name, String abbreviation) {
this.eraValue = eraValue;
this.since = since;
this.name = name;
this.abbreviation = abbreviation;
}
//-----------------------------------------------------------------------
/**
* Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
*
* @return the Sun private Era instance for this {@code JapaneseEra}.
*/
// sun.util.calendar.Era getPrivateEra() {
// return ERA_CONFIG[ordinal(eraValue)];
// }
LocalDate getSince() {
return since;
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code JapaneseEra} from an {@code int} value.
* <ul>
* <li>The value {@code 1} is associated with the 'Showa' era, because
* it contains 1970-01-01 (ISO calendar system).</li>
* <li>The values {@code -1} and {@code 0} are associated with two earlier
* eras, Meiji and Taisho, respectively.</li>
* <li>A value greater than {@code 1} is associated with a later era,
* beginning with Heisei ({@code 2}).</li>
* </ul>
* <p>
* Every instance of {@code JapaneseEra} that is returned from the {@link #values()}
* method has an int value (available via {@link Era#getValue()} which is
* accepted by this method.
*
* @param japaneseEra the era to represent
* @return the {@code JapaneseEra} singleton, not null
* @throws DateTimeException if the value is invalid
*/
public static JapaneseEra of(int japaneseEra) {
if (japaneseEra < MEIJI.eraValue || japaneseEra + ERA_OFFSET > KNOWN_ERAS.length) {
throw new DateTimeException("Invalid era: " + japaneseEra);
}
return KNOWN_ERAS[ordinal(japaneseEra)];
}
/**
* Returns the {@code JapaneseEra} with the name.
* <p>
* The string must match exactly the name of the era.
* (Extraneous whitespace characters are not permitted.)
*
* @param japaneseEra the japaneseEra name; non-null
* @return the {@code JapaneseEra} singleton, never null
* @throws IllegalArgumentException if there is not JapaneseEra with the specified name
*/
public static JapaneseEra valueOf(String japaneseEra) {
Objects.requireNonNull(japaneseEra, "japaneseEra");
for (JapaneseEra era : KNOWN_ERAS) {
if (era.getName().equals(japaneseEra)) {
return era;
}
}
throw new IllegalArgumentException("japaneseEra is invalid");
}
/**
* Returns an array of JapaneseEras.
* <p>
* This method may be used to iterate over the JapaneseEras as follows:
* <pre>
* for (JapaneseEra c : JapaneseEra.values())
* System.out.println(c);
* </pre>
*
* @return an array of JapaneseEras
*/
public static JapaneseEra[] values() {
return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
}
/**
* {@inheritDoc}
*
* @param style {@inheritDoc}
* @param locale {@inheritDoc}
*/
@Override
public String getDisplayName(TextStyle style, Locale locale) {
// If this JapaneseEra is a supplemental one, obtain the name from
// the era definition.
if (getValue() > N_ERA_CONSTANTS - ERA_OFFSET) {
Objects.requireNonNull(locale, "locale");
return style.asNormal() == TextStyle.NARROW ? getAbbreviation() : getName();
}
return Era.super.getDisplayName(style, locale);
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code JapaneseEra} from a date.
*
* @param date the date, not null
* @return the Era singleton, never null
*/
static JapaneseEra from(LocalDate date) {
if (date.isBefore(MEIJI_6_ISODATE)) {
throw new DateTimeException("JapaneseDate before Meiji 6 are not supported");
}
for (int i = KNOWN_ERAS.length - 1; i >= 0; i--) {
JapaneseEra era = KNOWN_ERAS[i];
if (date.compareTo(era.since) >= 0) {
return era;
}
}
return null;
}
// static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
// for (int i = ERA_CONFIG.length - 1; i >= 0; i--) {
// if (ERA_CONFIG[i].equals(privateEra)) {
// return KNOWN_ERAS[i];
// }
// }
// return null;
// }
//
// static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
// for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
// JapaneseEra era = KNOWN_ERAS[i];
// if (isoDate.compareTo(era.since) >= 0) {
// return ERA_CONFIG[i];
// }
// }
// return null;
// }
/**
* Returns the index into the arrays from the Era value.
* the eraValue is a valid Era number, -1..2.
*
* @param eraValue the era value to convert to the index
* @return the index of the current Era
*/
private static int ordinal(int eraValue) {
return eraValue + ERA_OFFSET - 1;
}
//-----------------------------------------------------------------------
/**
* Gets the numeric era {@code int} value.
* <p>
* The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
* Later eras are numbered from 2 ({@link #HEISEI}).
* Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})).
*
* @return the era value
*/
@Override
public int getValue() {
return eraValue;
}
//-----------------------------------------------------------------------
/**
* Gets the range of valid values for the specified field.
* <p>
* The range object expresses the minimum and maximum valid values for a field.
* This era is used to enhance the accuracy of the returned range.
* If it is not possible to return the range, because the field is not supported
* or for some other reason, an exception is thrown.
* <p>
* If the field is a {@link ChronoField} then the query is implemented here.
* The {@code ERA} field returns the range.
* All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
* <p>
* If the field is not a {@code ChronoField}, then the result of this method
* is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
* passing {@code this} as the argument.
* Whether the range can be obtained is determined by the field.
* <p>
* The range of valid Japanese eras can change over time due to the nature
* of the Japanese calendar system.
*
* @param field the field to query the range for, not null
* @return the range of valid values for the field, not null
* @throws DateTimeException if the range for the field cannot be obtained
* @throws UnsupportedTemporalTypeException if the unit is not supported
*/
@Override // override as super would return range from 0 to 1
public ValueRange range(TemporalField field) {
if (field == ERA) {
return JapaneseChronology.INSTANCE.range(ERA);
}
return Era.super.range(field);
}
//-----------------------------------------------------------------------
private String getAbbreviation() {
// return ERA_CONFIG[ordinal(getValue())].getAbbreviation();
return abbreviation;
}
private String getName() {
// return ERA_CONFIG[ordinal(getValue())].getName();
return name;
}
// For desugar: convenience method to get the following era, or null for the last one
JapaneseEra next() {
return this == getCurrentEra() ? null : of(eraValue + 1);
}
@Override
public String toString() {
return getName();
}
//-----------------------------------------------------------------------
/**
* Defend against malicious streams.
*
* @param s the stream to read
* @throws InvalidObjectException always
*/
private void readObject(ObjectInputStream s) throws InvalidObjectException {
throw new InvalidObjectException("Deserialization via serialization delegate");
}
//-----------------------------------------------------------------------
/**
* Writes the object using a
* <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
* @serialData
* <pre>
* out.writeByte(5); // identifies a JapaneseEra
* out.writeInt(getValue());
* </pre>
*
* @return the instance of {@code Ser}, not null
*/
private Object writeReplace() {
return new Ser(Ser.JAPANESE_ERA_TYPE, this);
}
void writeExternal(DataOutput out) throws IOException {
out.writeByte(this.getValue());
}
static JapaneseEra readExternal(DataInput in) throws IOException {
byte eraValue = in.readByte();
return JapaneseEra.of(eraValue);
}
}
