1 /*
2 * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
28 *
29 * All rights reserved.
30 *
31 * Redistribution and use in source and binary forms, with or without
32 * modification, are permitted provided that the following conditions are met:
33 *
34 * * Redistributions of source code must retain the above copyright notice,
35 * this list of conditions and the following disclaimer.
36 *
37 * * Redistributions in binary form must reproduce the above copyright notice,
38 * this list of conditions and the following disclaimer in the documentation
39 * and/or other materials provided with the distribution.
40 *
41 * * Neither the name of JSR-310 nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
46 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
47 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
48 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
49 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
50 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
52 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
53 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
54 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
55 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57 package java.time.chrono;
58
59 import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
60 import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
61 import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
62 import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
63 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
64 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
65 import static java.time.temporal.ChronoField.YEAR;
66
67 import java.io.DataInput;
68 import java.io.DataOutput;
69 import java.io.IOException;
70 import java.io.InvalidObjectException;
71 import java.io.ObjectInputStream;
72 import java.io.Serializable;
73 import java.time.Clock;
74 import java.time.DateTimeException;
75 import java.time.LocalDate;
76 import java.time.LocalTime;
77 import java.time.Period;
78 import java.time.ZoneId;
79 import java.time.temporal.ChronoField;
80 import java.time.temporal.TemporalAccessor;
81 import java.time.temporal.TemporalAdjuster;
82 import java.time.temporal.TemporalAmount;
83 import java.time.temporal.TemporalField;
84 import java.time.temporal.TemporalQuery;
85 import java.time.temporal.TemporalUnit;
86 import java.time.temporal.UnsupportedTemporalTypeException;
87 import java.time.temporal.ValueRange;
88 import java.util.Calendar;
89 import java.util.Objects;
90
91 import sun.util.calendar.CalendarDate;
92 import sun.util.calendar.LocalGregorianCalendar;
93
94 /**
95 * A date in the Japanese Imperial calendar system.
96 * <p>
97 * This date operates using the {@linkplain JapaneseChronology Japanese Imperial calendar}.
98 * This calendar system is primarily used in Japan.
99 * <p>
100 * The Japanese Imperial calendar system is the same as the ISO calendar system
101 * apart from the era-based year numbering. The proleptic-year is defined to be
102 * equal to the ISO proleptic-year.
103 * <p>
104 * Japan introduced the Gregorian calendar starting with Meiji 6.
105 * Only Meiji and later eras are supported;
106 * dates before Meiji 6, January 1 are not supported.
107 * <p>
108 * For example, the Japanese year "Heisei 24" corresponds to ISO year "2012".<br>
109 * Calling {@code japaneseDate.get(YEAR_OF_ERA)} will return 24.<br>
110 * Calling {@code japaneseDate.get(YEAR)} will return 2012.<br>
111 * Calling {@code japaneseDate.get(ERA)} will return 2, corresponding to
112 * {@code JapaneseChronology.ERA_HEISEI}.<br>
113 *
114 * <p>
115 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
116 * class; use of identity-sensitive operations (including reference equality
117 * ({@code ==}), identity hash code, or synchronization) on instances of
118 * {@code JapaneseDate} may have unpredictable results and should be avoided.
119 * The {@code equals} method should be used for comparisons.
120 *
121 * @implSpec
122 * This class is immutable and thread-safe.
123 *
124 * @since 1.8
125 */
126 public final class JapaneseDate
127 extends ChronoLocalDateImpl<JapaneseDate>
128 implements ChronoLocalDate, Serializable {
129
130 /**
131 * Serialization version.
132 */
133 @java.io.Serial
134 private static final long serialVersionUID = -305327627230580483L;
135
136 /**
137 * The underlying ISO local date.
138 */
139 private final transient LocalDate isoDate;
140 /**
141 * The JapaneseEra of this date.
142 */
143 private transient JapaneseEra era;
144 /**
145 * The Japanese imperial calendar year of this date.
146 */
147 private transient int yearOfEra;
148
149 /**
150 * The first day supported by the JapaneseChronology is Meiji 6, January 1st.
151 */
152 static final LocalDate MEIJI_6_ISODATE = LocalDate.of(1873, 1, 1);
153
154 //-----------------------------------------------------------------------
155 /**
156 * Obtains the current {@code JapaneseDate} from the system clock in the default time-zone.
157 * <p>
158 * This will query the {@link Clock#systemDefaultZone() system clock} in the default
159 * time-zone to obtain the current date.
160 * <p>
161 * Using this method will prevent the ability to use an alternate clock for testing
162 * because the clock is hard-coded.
163 *
164 * @return the current date using the system clock and default time-zone, not null
165 */
166 public static JapaneseDate now() {
167 return now(Clock.systemDefaultZone());
168 }
169
170 /**
171 * Obtains the current {@code JapaneseDate} from the system clock in the specified time-zone.
172 * <p>
173 * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
174 * Specifying the time-zone avoids dependence on the default time-zone.
175 * <p>
176 * Using this method will prevent the ability to use an alternate clock for testing
177 * because the clock is hard-coded.
178 *
179 * @param zone the zone ID to use, not null
180 * @return the current date using the system clock, not null
181 */
182 public static JapaneseDate now(ZoneId zone) {
183 return now(Clock.system(zone));
184 }
185
186 /**
187 * Obtains the current {@code JapaneseDate} from the specified clock.
188 * <p>
189 * This will query the specified clock to obtain the current date - today.
190 * Using this method allows the use of an alternate clock for testing.
191 * The alternate clock may be introduced using {@linkplain Clock dependency injection}.
192 *
193 * @param clock the clock to use, not null
194 * @return the current date, not null
195 * @throws DateTimeException if the current date cannot be obtained
196 */
197 public static JapaneseDate now(Clock clock) {
198 return new JapaneseDate(LocalDate.now(clock));
199 }
200
201 /**
202 * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
203 * system from the era, year-of-era, month-of-year and day-of-month fields.
204 * <p>
205 * This returns a {@code JapaneseDate} with the specified fields.
206 * The day must be valid for the year and month, otherwise an exception will be thrown.
207 * <p>
208 * The Japanese month and day-of-month are the same as those in the
209 * ISO calendar system. They are not reset when the era changes.
210 * For example:
211 * <pre>
212 * 6th Jan Showa 64 = ISO 1989-01-06
213 * 7th Jan Showa 64 = ISO 1989-01-07
214 * 8th Jan Heisei 1 = ISO 1989-01-08
215 * 9th Jan Heisei 1 = ISO 1989-01-09
216 * </pre>
217 *
218 * @param era the Japanese era, not null
219 * @param yearOfEra the Japanese year-of-era
220 * @param month the Japanese month-of-year, from 1 to 12
221 * @param dayOfMonth the Japanese day-of-month, from 1 to 31
222 * @return the date in Japanese calendar system, not null
223 * @throws DateTimeException if the value of any field is out of range,
224 * or if the day-of-month is invalid for the month-year,
225 * or if the date is not a Japanese era
226 */
227 public static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) {
228 Objects.requireNonNull(era, "era");
229 LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
230 jdate.setEra(era.getPrivateEra()).setDate(yearOfEra, month, dayOfMonth);
231 if (!JapaneseChronology.JCAL.validate(jdate)) {
232 throw new DateTimeException("year, month, and day not valid for Era");
233 }
234 LocalDate date = LocalDate.of(jdate.getNormalizedYear(), month, dayOfMonth);
235 return new JapaneseDate(era, yearOfEra, date);
236 }
237
238 /**
239 * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
240 * system from the proleptic-year, month-of-year and day-of-month fields.
241 * <p>
242 * This returns a {@code JapaneseDate} with the specified fields.
243 * The day must be valid for the year and month, otherwise an exception will be thrown.
244 * <p>
245 * The Japanese proleptic year, month and day-of-month are the same as those
246 * in the ISO calendar system. They are not reset when the era changes.
247 *
248 * @param prolepticYear the Japanese proleptic-year
249 * @param month the Japanese month-of-year, from 1 to 12
250 * @param dayOfMonth the Japanese day-of-month, from 1 to 31
251 * @return the date in Japanese calendar system, not null
252 * @throws DateTimeException if the value of any field is out of range,
253 * or if the day-of-month is invalid for the month-year
254 */
255 public static JapaneseDate of(int prolepticYear, int month, int dayOfMonth) {
256 return new JapaneseDate(LocalDate.of(prolepticYear, month, dayOfMonth));
257 }
258
259 /**
260 * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
261 * system from the era, year-of-era and day-of-year fields.
262 * <p>
263 * This returns a {@code JapaneseDate} with the specified fields.
264 * The day must be valid for the year, otherwise an exception will be thrown.
265 * <p>
266 * The day-of-year in this factory is expressed relative to the start of the year-of-era.
267 * This definition changes the normal meaning of day-of-year only in those years
268 * where the year-of-era is reset to one due to a change in the era.
269 * For example:
270 * <pre>
271 * 6th Jan Showa 64 = day-of-year 6
272 * 7th Jan Showa 64 = day-of-year 7
273 * 8th Jan Heisei 1 = day-of-year 1
274 * 9th Jan Heisei 1 = day-of-year 2
275 * </pre>
276 *
277 * @param era the Japanese era, not null
278 * @param yearOfEra the Japanese year-of-era
279 * @param dayOfYear the chronology day-of-year, from 1 to 366
280 * @return the date in Japanese calendar system, not null
281 * @throws DateTimeException if the value of any field is out of range,
282 * or if the day-of-year is invalid for the year
283 */
284 static JapaneseDate ofYearDay(JapaneseEra era, int yearOfEra, int dayOfYear) {
285 Objects.requireNonNull(era, "era");
286 CalendarDate firstDay = era.getPrivateEra().getSinceDate();
287 LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
288 jdate.setEra(era.getPrivateEra());
289 if (yearOfEra == 1) {
290 jdate.setDate(yearOfEra, firstDay.getMonth(), firstDay.getDayOfMonth() + dayOfYear - 1);
291 } else {
292 jdate.setDate(yearOfEra, 1, dayOfYear);
293 }
294 JapaneseChronology.JCAL.normalize(jdate);
295 if (era.getPrivateEra() != jdate.getEra() || yearOfEra != jdate.getYear()) {
296 throw new DateTimeException("Invalid parameters");
297 }
298 LocalDate localdate = LocalDate.of(jdate.getNormalizedYear(),
299 jdate.getMonth(), jdate.getDayOfMonth());
300 return new JapaneseDate(era, yearOfEra, localdate);
301 }
302
303 /**
304 * Obtains a {@code JapaneseDate} from a temporal object.
305 * <p>
306 * This obtains a date in the Japanese calendar system based on the specified temporal.
307 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
308 * which this factory converts to an instance of {@code JapaneseDate}.
309 * <p>
310 * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
311 * field, which is standardized across calendar systems.
312 * <p>
313 * This method matches the signature of the functional interface {@link TemporalQuery}
314 * allowing it to be used as a query via method reference, {@code JapaneseDate::from}.
315 *
316 * @param temporal the temporal object to convert, not null
317 * @return the date in Japanese calendar system, not null
318 * @throws DateTimeException if unable to convert to a {@code JapaneseDate}
319 */
320 public static JapaneseDate from(TemporalAccessor temporal) {
321 return JapaneseChronology.INSTANCE.date(temporal);
322 }
323
324 //-----------------------------------------------------------------------
325 /**
326 * Creates an instance from an ISO date.
327 *
328 * @param isoDate the standard local date, validated not null
329 */
330 JapaneseDate(LocalDate isoDate) {
331 if (isoDate.isBefore(MEIJI_6_ISODATE)) {
332 throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
333 }
334 LocalGregorianCalendar.Date jdate = toPrivateJapaneseDate(isoDate);
335 this.era = JapaneseEra.toJapaneseEra(jdate.getEra());
336 this.yearOfEra = jdate.getYear();
337 this.isoDate = isoDate;
338 }
339
340 /**
341 * Constructs a {@code JapaneseDate}. This constructor does NOT validate the given parameters,
342 * and {@code era} and {@code year} must agree with {@code isoDate}.
343 *
344 * @param era the era, validated not null
345 * @param year the year-of-era, validated
346 * @param isoDate the standard local date, validated not null
347 */
348 JapaneseDate(JapaneseEra era, int year, LocalDate isoDate) {
349 if (isoDate.isBefore(MEIJI_6_ISODATE)) {
350 throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
351 }
352 this.era = era;
353 this.yearOfEra = year;
354 this.isoDate = isoDate;
355 }
356
357 //-----------------------------------------------------------------------
358 /**
359 * Gets the chronology of this date, which is the Japanese calendar system.
360 * <p>
361 * The {@code Chronology} represents the calendar system in use.
362 * The era and other fields in {@link ChronoField} are defined by the chronology.
363 *
364 * @return the Japanese chronology, not null
365 */
366 @Override
367 public JapaneseChronology getChronology() {
368 return JapaneseChronology.INSTANCE;
369 }
370
371 /**
372 * Gets the era applicable at this date.
373 * <p>
374 * The Japanese calendar system has multiple eras defined by {@link JapaneseEra}.
375 *
376 * @return the era applicable at this date, not null
377 */
378 @Override
379 public JapaneseEra getEra() {
380 return era;
381 }
382
383 /**
384 * Returns the length of the month represented by this date.
385 * <p>
386 * This returns the length of the month in days.
387 * Month lengths match those of the ISO calendar system.
388 *
389 * @return the length of the month in days
390 */
391 @Override
392 public int lengthOfMonth() {
393 return isoDate.lengthOfMonth();
394 }
395
396 @Override
397 public int lengthOfYear() {
398 Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
399 jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
400 jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
401 return jcal.getActualMaximum(Calendar.DAY_OF_YEAR);
402 }
403
404 //-----------------------------------------------------------------------
405 /**
406 * Checks if the specified field is supported.
407 * <p>
408 * This checks if this date can be queried for the specified field.
409 * If false, then calling the {@link #range(TemporalField) range} and
410 * {@link #get(TemporalField) get} methods will throw an exception.
411 * <p>
412 * If the field is a {@link ChronoField} then the query is implemented here.
413 * The supported fields are:
414 * <ul>
415 * <li>{@code DAY_OF_WEEK}
416 * <li>{@code DAY_OF_MONTH}
417 * <li>{@code DAY_OF_YEAR}
418 * <li>{@code EPOCH_DAY}
419 * <li>{@code MONTH_OF_YEAR}
420 * <li>{@code PROLEPTIC_MONTH}
421 * <li>{@code YEAR_OF_ERA}
422 * <li>{@code YEAR}
423 * <li>{@code ERA}
424 * </ul>
425 * All other {@code ChronoField} instances will return false.
426 * <p>
427 * If the field is not a {@code ChronoField}, then the result of this method
428 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
429 * passing {@code this} as the argument.
430 * Whether the field is supported is determined by the field.
431 *
432 * @param field the field to check, null returns false
433 * @return true if the field is supported on this date, false if not
434 */
435 @Override
436 public boolean isSupported(TemporalField field) {
437 if (field == ALIGNED_DAY_OF_WEEK_IN_MONTH || field == ALIGNED_DAY_OF_WEEK_IN_YEAR ||
438 field == ALIGNED_WEEK_OF_MONTH || field == ALIGNED_WEEK_OF_YEAR) {
439 return false;
440 }
441 return super.isSupported(field);
442 }
443
444 @Override
445 public ValueRange range(TemporalField field) {
446 if (field instanceof ChronoField) {
447 if (isSupported(field)) {
448 ChronoField f = (ChronoField) field;
449 switch (f) {
450 case DAY_OF_MONTH: return ValueRange.of(1, lengthOfMonth());
451 case DAY_OF_YEAR: return ValueRange.of(1, lengthOfYear());
452 case YEAR_OF_ERA: {
453 Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
454 jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
455 jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
456 return ValueRange.of(1, jcal.getActualMaximum(Calendar.YEAR));
457 }
458 }
459 return getChronology().range(f);
460 }
461 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
462 }
463 return field.rangeRefinedBy(this);
464 }
465
466 @Override
467 public long getLong(TemporalField field) {
468 if (field instanceof ChronoField) {
469 // same as ISO:
470 // DAY_OF_WEEK, DAY_OF_MONTH, EPOCH_DAY, MONTH_OF_YEAR, PROLEPTIC_MONTH, YEAR
471 //
472 // calendar specific fields
473 // DAY_OF_YEAR, YEAR_OF_ERA, ERA
474 switch ((ChronoField) field) {
475 case ALIGNED_DAY_OF_WEEK_IN_MONTH:
476 case ALIGNED_DAY_OF_WEEK_IN_YEAR:
477 case ALIGNED_WEEK_OF_MONTH:
478 case ALIGNED_WEEK_OF_YEAR:
479 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
480 case YEAR_OF_ERA:
481 return yearOfEra;
482 case ERA:
483 return era.getValue();
484 case DAY_OF_YEAR:
485 Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
486 jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
487 jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
488 return jcal.get(Calendar.DAY_OF_YEAR);
489 }
490 return isoDate.getLong(field);
491 }
492 return field.getFrom(this);
493 }
494
495 /**
496 * Returns a {@code LocalGregorianCalendar.Date} converted from the given {@code isoDate}.
497 *
498 * @param isoDate the local date, not null
499 * @return a {@code LocalGregorianCalendar.Date}, not null
500 */
501 private static LocalGregorianCalendar.Date toPrivateJapaneseDate(LocalDate isoDate) {
502 LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
503 sun.util.calendar.Era sunEra = JapaneseEra.privateEraFrom(isoDate);
504 int year = isoDate.getYear();
505 if (sunEra != null) {
506 year -= sunEra.getSinceDate().getYear() - 1;
507 }
508 jdate.setEra(sunEra).setYear(year).setMonth(isoDate.getMonthValue()).setDayOfMonth(isoDate.getDayOfMonth());
509 JapaneseChronology.JCAL.normalize(jdate);
510 return jdate;
511 }
512
513 //-----------------------------------------------------------------------
514 @Override
515 public JapaneseDate with(TemporalField field, long newValue) {
516 if (field instanceof ChronoField) {
517 ChronoField f = (ChronoField) field;
518 if (getLong(f) == newValue) { // getLong() validates for supported fields
519 return this;
520 }
521 switch (f) {
522 case YEAR_OF_ERA:
523 case YEAR:
524 case ERA: {
525 int nvalue = getChronology().range(f).checkValidIntValue(newValue, f);
526 switch (f) {
527 case YEAR_OF_ERA:
528 return this.withYear(nvalue);
529 case YEAR:
530 return with(isoDate.withYear(nvalue));
531 case ERA: {
532 return this.withYear(JapaneseEra.of(nvalue), yearOfEra);
533 }
534 }
535 }
536 }
537 // YEAR, PROLEPTIC_MONTH and others are same as ISO
538 return with(isoDate.with(field, newValue));
539 }
540 return super.with(field, newValue);
541 }
542
543 /**
544 * {@inheritDoc}
545 * @throws DateTimeException {@inheritDoc}
546 * @throws ArithmeticException {@inheritDoc}
547 */
548 @Override
549 public JapaneseDate with(TemporalAdjuster adjuster) {
550 return super.with(adjuster);
551 }
552
553 /**
554 * {@inheritDoc}
555 * @throws DateTimeException {@inheritDoc}
556 * @throws ArithmeticException {@inheritDoc}
557 */
558 @Override
559 public JapaneseDate plus(TemporalAmount amount) {
560 return super.plus(amount);
561 }
562
563 /**
564 * {@inheritDoc}
565 * @throws DateTimeException {@inheritDoc}
566 * @throws ArithmeticException {@inheritDoc}
567 */
568 @Override
569 public JapaneseDate minus(TemporalAmount amount) {
570 return super.minus(amount);
571 }
572 //-----------------------------------------------------------------------
573 /**
574 * Returns a copy of this date with the year altered.
575 * <p>
576 * This method changes the year of the date.
577 * If the month-day is invalid for the year, then the previous valid day
578 * will be selected instead.
579 * <p>
580 * This instance is immutable and unaffected by this method call.
581 *
582 * @param era the era to set in the result, not null
583 * @param yearOfEra the year-of-era to set in the returned date
584 * @return a {@code JapaneseDate} based on this date with the requested year, never null
585 * @throws DateTimeException if {@code year} is invalid
586 */
587 private JapaneseDate withYear(JapaneseEra era, int yearOfEra) {
588 int year = JapaneseChronology.INSTANCE.prolepticYear(era, yearOfEra);
589 return with(isoDate.withYear(year));
590 }
591
592 /**
593 * Returns a copy of this date with the year-of-era altered.
594 * <p>
595 * This method changes the year-of-era of the date.
596 * If the month-day is invalid for the year, then the previous valid day
597 * will be selected instead.
598 * <p>
599 * This instance is immutable and unaffected by this method call.
600 *
601 * @param year the year to set in the returned date
602 * @return a {@code JapaneseDate} based on this date with the requested year-of-era, never null
603 * @throws DateTimeException if {@code year} is invalid
604 */
605 private JapaneseDate withYear(int year) {
606 return withYear(getEra(), year);
607 }
608
609 //-----------------------------------------------------------------------
610 @Override
611 JapaneseDate plusYears(long years) {
612 return with(isoDate.plusYears(years));
613 }
614
615 @Override
616 JapaneseDate plusMonths(long months) {
617 return with(isoDate.plusMonths(months));
618 }
619
620 @Override
621 JapaneseDate plusWeeks(long weeksToAdd) {
622 return with(isoDate.plusWeeks(weeksToAdd));
623 }
624
625 @Override
626 JapaneseDate plusDays(long days) {
627 return with(isoDate.plusDays(days));
628 }
629
630 @Override
631 public JapaneseDate plus(long amountToAdd, TemporalUnit unit) {
632 return super.plus(amountToAdd, unit);
633 }
634
635 @Override
636 public JapaneseDate minus(long amountToAdd, TemporalUnit unit) {
637 return super.minus(amountToAdd, unit);
638 }
639
640 @Override
641 JapaneseDate minusYears(long yearsToSubtract) {
642 return super.minusYears(yearsToSubtract);
643 }
644
645 @Override
646 JapaneseDate minusMonths(long monthsToSubtract) {
647 return super.minusMonths(monthsToSubtract);
648 }
649
650 @Override
651 JapaneseDate minusWeeks(long weeksToSubtract) {
652 return super.minusWeeks(weeksToSubtract);
653 }
654
655 @Override
656 JapaneseDate minusDays(long daysToSubtract) {
657 return super.minusDays(daysToSubtract);
658 }
659
660 private JapaneseDate with(LocalDate newDate) {
661 return (newDate.equals(isoDate) ? this : new JapaneseDate(newDate));
662 }
663
664 @Override // for javadoc and covariant return type
665 @SuppressWarnings("unchecked")
666 public final ChronoLocalDateTime<JapaneseDate> atTime(LocalTime localTime) {
667 return (ChronoLocalDateTime<JapaneseDate>)super.atTime(localTime);
668 }
669
670 @Override
671 public ChronoPeriod until(ChronoLocalDate endDate) {
672 Period period = isoDate.until(endDate);
673 return getChronology().period(period.getYears(), period.getMonths(), period.getDays());
674 }
675
676 @Override // override for performance
677 public long toEpochDay() {
678 return isoDate.toEpochDay();
679 }
680
681 //-------------------------------------------------------------------------
682 /**
683 * Compares this date to another date, including the chronology.
684 * <p>
685 * Compares this {@code JapaneseDate} with another ensuring that the date is the same.
686 * <p>
687 * Only objects of type {@code JapaneseDate} are compared, other types return false.
688 * To compare the dates of two {@code TemporalAccessor} instances, including dates
689 * in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
690 *
691 * @param obj the object to check, null returns false
692 * @return true if this is equal to the other date
693 */
694 @Override // override for performance
695 public boolean equals(Object obj) {
696 if (this == obj) {
697 return true;
698 }
699 if (obj instanceof JapaneseDate) {
700 JapaneseDate otherDate = (JapaneseDate) obj;
701 return this.isoDate.equals(otherDate.isoDate);
702 }
703 return false;
704 }
705
706 /**
707 * A hash code for this date.
708 *
709 * @return a suitable hash code based only on the Chronology and the date
710 */
711 @Override // override for performance
712 public int hashCode() {
713 return getChronology().getId().hashCode() ^ isoDate.hashCode();
714 }
715
716 //-----------------------------------------------------------------------
717 /**
718 * Defend against malicious streams.
719 *
720 * @param s the stream to read
721 * @throws InvalidObjectException always
722 */
723 @java.io.Serial
724 private void readObject(ObjectInputStream s) throws InvalidObjectException {
725 throw new InvalidObjectException("Deserialization via serialization delegate");
726 }
727
728 /**
729 * Writes the object using a
730 * <a href="{@docRoot}/serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
731 * @serialData
732 * <pre>
733 * out.writeByte(4); // identifies a JapaneseDate
734 * out.writeInt(get(YEAR));
735 * out.writeByte(get(MONTH_OF_YEAR));
736 * out.writeByte(get(DAY_OF_MONTH));
737 * </pre>
738 *
739 * @return the instance of {@code Ser}, not null
740 */
741 @java.io.Serial
742 private Object writeReplace() {
743 return new Ser(Ser.JAPANESE_DATE_TYPE, this);
744 }
745
746 void writeExternal(DataOutput out) throws IOException {
747 // JapaneseChronology is implicit in the JAPANESE_DATE_TYPE
748 out.writeInt(get(YEAR));
749 out.writeByte(get(MONTH_OF_YEAR));
750 out.writeByte(get(DAY_OF_MONTH));
751 }
752
753 static JapaneseDate readExternal(DataInput in) throws IOException {
754 int year = in.readInt();
755 int month = in.readByte();
756 int dayOfMonth = in.readByte();
757 return JapaneseChronology.INSTANCE.date(year, month, dayOfMonth);
758 }
759
760 }