* This date operates using the {@linkplain JapaneseChronology Japanese Imperial calendar}. * 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. The proleptic-year is defined to be * equal to the ISO proleptic-year. *
* 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. *
* For example, the Japanese year "Heisei 24" corresponds to ISO year "2012".
* This will query the {@link Clock#systemDefaultZone() system clock} in the default
* time-zone to obtain the current date.
*
* 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.
*
* 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.
*
* 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.
*
* 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.
*
* 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.
*
* 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:
*
* 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.
*
* 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} representing a date in the Japanese calendar
* system from the era, year-of-era and day-of-year fields.
*
* This returns a {@code JapaneseDate} with the specified fields.
* The day must be valid for the year, otherwise an exception will be thrown.
*
* 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:
*
* 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}.
*
* The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
* field, which is standardized across calendar systems.
*
* 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(MEIJI_6_ISODATE)) {
throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
}
LocalGregorianCalendar.Date jdate = toPrivateJapaneseDate(isoDate);
this.era = JapaneseEra.toJapaneseEra(jdate.getEra());
this.yearOfEra = jdate.getYear();
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(MEIJI_6_ISODATE)) {
throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
}
this.era = era;
this.yearOfEra = year;
this.isoDate = isoDate;
}
//-----------------------------------------------------------------------
/**
* Gets the chronology of this date, which is the Japanese calendar system.
*
* The {@code Chronology} represents the calendar system in use.
* The era and other fields in {@link ChronoField} are defined by the chronology.
*
* @return the Japanese chronology, not null
*/
@Override
public JapaneseChronology getChronology() {
return JapaneseChronology.INSTANCE;
}
/**
* Gets the era applicable at this date.
*
* The Japanese calendar system has multiple eras defined by {@link JapaneseEra}.
*
* @return the era applicable at this date, not null
*/
@Override
public JapaneseEra getEra() {
return era;
}
/**
* Returns the length of the month represented by this date.
*
* This returns the length of the month in days.
* Month lengths match those of the ISO calendar system.
*
* @return the length of the month in days
*/
@Override
public int lengthOfMonth() {
return isoDate.lengthOfMonth();
}
@Override
public int lengthOfYear() {
// Android-changed: use #createCalendar() to create calendar.
Calendar jcal = JapaneseChronology.createCalendar();
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.
*
* 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.
*
* If the field is a {@link ChronoField} then the query is implemented here.
* The supported fields are:
*
* 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 == ALIGNED_DAY_OF_WEEK_IN_MONTH || field == ALIGNED_DAY_OF_WEEK_IN_YEAR ||
field == ALIGNED_WEEK_OF_MONTH || field == ALIGNED_WEEK_OF_YEAR) {
return false;
}
return ChronoLocalDate.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_MONTH: return ValueRange.of(1, lengthOfMonth());
case DAY_OF_YEAR: return ValueRange.of(1, lengthOfYear());
case YEAR_OF_ERA: {
// Android-changed: use #createCalendar() to create calendar.
Calendar jcal = JapaneseChronology.createCalendar();
jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
return ValueRange.of(1, jcal.getActualMaximum(Calendar.YEAR));
}
}
return getChronology().range(f);
}
throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
}
return field.rangeRefinedBy(this);
}
@Override
public long getLong(TemporalField field) {
if (field instanceof ChronoField) {
// same as ISO:
// DAY_OF_WEEK, DAY_OF_MONTH, EPOCH_DAY, MONTH_OF_YEAR, PROLEPTIC_MONTH, YEAR
//
// calendar specific fields
// DAY_OF_YEAR, YEAR_OF_ERA, ERA
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:
// Android-changed: use #createCalendar() to create calendar.
Calendar jcal = JapaneseChronology.createCalendar();
jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
return jcal.get(Calendar.DAY_OF_YEAR);
}
return isoDate.getLong(field);
}
return field.getFrom(this);
}
/**
* Returns a {@code LocalGregorianCalendar.Date} converted from the given {@code isoDate}.
*
* @param isoDate the local date, not null
* @return a {@code LocalGregorianCalendar.Date}, not null
*/
private static LocalGregorianCalendar.Date toPrivateJapaneseDate(LocalDate isoDate) {
LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
sun.util.calendar.Era sunEra = JapaneseEra.privateEraFrom(isoDate);
int year = isoDate.getYear();
if (sunEra != null) {
year -= sunEra.getSinceDate().getYear() - 1;
}
jdate.setEra(sunEra).setYear(year).setMonth(isoDate.getMonthValue()).setDayOfMonth(isoDate.getDayOfMonth());
JapaneseChronology.JCAL.normalize(jdate);
return jdate;
}
//-----------------------------------------------------------------------
@Override
public JapaneseDate with(TemporalField field, long newValue) {
if (field instanceof ChronoField) {
ChronoField f = (ChronoField) field;
if (getLong(f) == newValue) { // getLong() validates for supported fields
return this;
}
switch (f) {
case YEAR_OF_ERA:
case YEAR:
case ERA: {
int nvalue = getChronology().range(f).checkValidIntValue(newValue, f);
switch (f) {
case YEAR_OF_ERA:
return this.withYear(nvalue);
case YEAR:
return with(isoDate.withYear(nvalue));
case ERA: {
return this.withYear(JapaneseEra.of(nvalue), yearOfEra);
}
}
}
}
// YEAR, PROLEPTIC_MONTH and others are same as ISO
return with(isoDate.with(field, newValue));
}
return super.with(field, newValue);
}
/**
* {@inheritDoc}
* @throws DateTimeException {@inheritDoc}
* @throws ArithmeticException {@inheritDoc}
*/
@Override
public JapaneseDate with(TemporalAdjuster adjuster) {
return super.with(adjuster);
}
/**
* {@inheritDoc}
* @throws DateTimeException {@inheritDoc}
* @throws ArithmeticException {@inheritDoc}
*/
@Override
public JapaneseDate plus(TemporalAmount amount) {
return super.plus(amount);
}
/**
* {@inheritDoc}
* @throws DateTimeException {@inheritDoc}
* @throws ArithmeticException {@inheritDoc}
*/
@Override
public JapaneseDate minus(TemporalAmount amount) {
return super.minus(amount);
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this date with the year altered.
*
* 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.
*
* 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.
*
* 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.
*
* 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 plusWeeks(long weeksToAdd) {
return with(isoDate.plusWeeks(weeksToAdd));
}
@Override
JapaneseDate plusDays(long days) {
return with(isoDate.plusDays(days));
}
@Override
public JapaneseDate plus(long amountToAdd, TemporalUnit unit) {
return super.plus(amountToAdd, unit);
}
@Override
public JapaneseDate minus(long amountToAdd, TemporalUnit unit) {
return super.minus(amountToAdd, unit);
}
@Override
JapaneseDate minusYears(long yearsToSubtract) {
return super.minusYears(yearsToSubtract);
}
@Override
JapaneseDate minusMonths(long monthsToSubtract) {
return super.minusMonths(monthsToSubtract);
}
@Override
JapaneseDate minusWeeks(long weeksToSubtract) {
return super.minusWeeks(weeksToSubtract);
}
@Override
JapaneseDate minusDays(long daysToSubtract) {
return super.minusDays(daysToSubtract);
}
private JapaneseDate with(LocalDate newDate) {
return (newDate.equals(isoDate) ? this : new JapaneseDate(newDate));
}
@Override // for javadoc and covariant return type
@SuppressWarnings("unchecked")
public final ChronoLocalDateTime
* Compares this {@code JapaneseDate} with another ensuring that the date is the same.
*
* Only objects of type {@code JapaneseDate} are compared, other types return false.
* To compare the dates of two {@code TemporalAccessor} instances, including dates
* in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
*
* @param obj the object to check, null returns false
* @return true if this is equal to the other date
*/
@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;
}
/**
* A hash code for this date.
*
* @return a suitable hash code based only on the Chronology and the date
*/
@Override // override for performance
public int hashCode() {
return getChronology().getId().hashCode() ^ isoDate.hashCode();
}
//-----------------------------------------------------------------------
/**
* 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
* dedicated serialized form.
* @serialData
*
* Calling {@code japaneseDate.get(YEAR_OF_ERA)} will return 24.
* Calling {@code japaneseDate.get(YEAR)} will return 2012.
* Calling {@code japaneseDate.get(ERA)} will return 2, corresponding to
* {@code JapaneseChronology.ERA_HEISEI}.
*
* @implSpec
* This class is immutable and thread-safe.
*
* @since 1.8
*/
public final class JapaneseDate
extends ChronoLocalDateImpl
* 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
*
*
* @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,
* or if the date is not a Japanese era
*/
public static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) {
Objects.requireNonNull(era, "era");
LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
jdate.setEra(era.getPrivateEra()).setDate(yearOfEra, month, dayOfMonth);
if (!JapaneseChronology.JCAL.validate(jdate)) {
throw new DateTimeException("year, month, and day not valid for Era");
}
LocalDate date = LocalDate.of(jdate.getNormalizedYear(), month, dayOfMonth);
return new JapaneseDate(era, yearOfEra, date);
}
/**
* Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
* system from the proleptic-year, month-of-year and day-of-month fields.
*
* 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
*
*
* @param era the Japanese era, not null
* @param yearOfEra the Japanese year-of-era
* @param dayOfYear the chronology day-of-year, from 1 to 366
* @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) {
Objects.requireNonNull(era, "era");
CalendarDate firstDay = era.getPrivateEra().getSinceDate();
LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
jdate.setEra(era.getPrivateEra());
if (yearOfEra == 1) {
jdate.setDate(yearOfEra, firstDay.getMonth(), firstDay.getDayOfMonth() + dayOfYear - 1);
} else {
jdate.setDate(yearOfEra, 1, dayOfYear);
}
JapaneseChronology.JCAL.normalize(jdate);
if (era.getPrivateEra() != jdate.getEra() || yearOfEra != jdate.getYear()) {
throw new DateTimeException("Invalid parameters");
}
LocalDate localdate = LocalDate.of(jdate.getNormalizedYear(),
jdate.getMonth(), jdate.getDayOfMonth());
return new JapaneseDate(era, yearOfEra, localdate);
}
/**
* Obtains a {@code JapaneseDate} from a temporal object.
*
*
* All other {@code ChronoField} instances will return false.
*
* out.writeByte(4); // identifies a JapaneseDate
* out.writeInt(get(YEAR));
* out.writeByte(get(MONTH_OF_YEAR));
* out.writeByte(get(DAY_OF_MONTH));
*
*
* @return the instance of {@code Ser}, not null
*/
private Object writeReplace() {
return new Ser(Ser.JAPANESE_DATE_TYPE, this);
}
void writeExternal(DataOutput out) throws IOException {
// JapaneseChronology is implicit in the JAPANESE_DATE_TYPE
out.writeInt(get(YEAR));
out.writeByte(get(MONTH_OF_YEAR));
out.writeByte(get(DAY_OF_MONTH));
}
static JapaneseDate readExternal(DataInput in) throws IOException {
int year = in.readInt();
int month = in.readByte();
int dayOfMonth = in.readByte();
return JapaneseChronology.INSTANCE.date(year, month, dayOfMonth);
}
}