1 /*
2 * Copyright (c) 2012, 2016, 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/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 private static final long serialVersionUID = -305327627230580483L;
134
135 /**
136 * The underlying ISO local date.
137 */
138 private final transient LocalDate isoDate;
139 /**
140 * The JapaneseEra of this date.
141 */
142 private transient JapaneseEra era;
143 /**
144 * The Japanese imperial calendar year of this date.
145 */
146 private transient int yearOfEra;
147
148 /**
149 * The first day supported by the JapaneseChronology is Meiji 6, January 1st.
150 */
151 static final LocalDate MEIJI_6_ISODATE = LocalDate.of(1873, 1, 1);
152
153 //-----------------------------------------------------------------------
154 /**
155 * Obtains the current {@code JapaneseDate} from the system clock in the default time-zone.
156 * <p>
157 * This will query the {@link Clock#systemDefaultZone() system clock} in the default
158 * time-zone to obtain the current date.
159 * <p>
160 * Using this method will prevent the ability to use an alternate clock for testing
161 * because the clock is hard-coded.
162 *
163 * @return the current date using the system clock and default time-zone, not null
164 */
165 public static JapaneseDate now() {
166 return now(Clock.systemDefaultZone());
167 }
168
169 /**
170 * Obtains the current {@code JapaneseDate} from the system clock in the specified time-zone.
171 * <p>
172 * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
173 * Specifying the time-zone avoids dependence on the default time-zone.
174 * <p>
175 * Using this method will prevent the ability to use an alternate clock for testing
176 * because the clock is hard-coded.
177 *
178 * @param zone the zone ID to use, not null
179 * @return the current date using the system clock, not null
180 */
181 public static JapaneseDate now(ZoneId zone) {
182 return now(Clock.system(zone));
183 }
184
185 /**
186 * Obtains the current {@code JapaneseDate} from the specified clock.
187 * <p>
188 * This will query the specified clock to obtain the current date - today.
189 * Using this method allows the use of an alternate clock for testing.
190 * The alternate clock may be introduced using {@linkplain Clock dependency injection}.
191 *
192 * @param clock the clock to use, not null
193 * @return the current date, not null
194 * @throws DateTimeException if the current date cannot be obtained
195 */
196 public static JapaneseDate now(Clock clock) {
197 return new JapaneseDate(LocalDate.now(clock));
198 }
199
200 /**
201 * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
202 * system from the era, year-of-era, month-of-year and day-of-month fields.
203 * <p>
204 * This returns a {@code JapaneseDate} with the specified fields.
205 * The day must be valid for the year and month, otherwise an exception will be thrown.
206 * <p>
207 * The Japanese month and day-of-month are the same as those in the
208 * ISO calendar system. They are not reset when the era changes.
209 * For example:
210 * <pre>
211 * 6th Jan Showa 64 = ISO 1989-01-06
212 * 7th Jan Showa 64 = ISO 1989-01-07
213 * 8th Jan Heisei 1 = ISO 1989-01-08
214 * 9th Jan Heisei 1 = ISO 1989-01-09
215 * </pre>
216 *
217 * @param era the Japanese era, not null
218 * @param yearOfEra the Japanese year-of-era
219 * @param month the Japanese month-of-year, from 1 to 12
220 * @param dayOfMonth the Japanese day-of-month, from 1 to 31
221 * @return the date in Japanese calendar system, not null
222 * @throws DateTimeException if the value of any field is out of range,
223 * or if the day-of-month is invalid for the month-year,
224 * or if the date is not a Japanese era
225 */
226 public static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) {
227 Objects.requireNonNull(era, "era");
228 LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
229 jdate.setEra(era.getPrivateEra()).setDate(yearOfEra, month, dayOfMonth);
230 if (!JapaneseChronology.JCAL.validate(jdate)) {
231 throw new DateTimeException("year, month, and day not valid for Era");
232 }
233 LocalDate date = LocalDate.of(jdate.getNormalizedYear(), month, dayOfMonth);
234 return new JapaneseDate(era, yearOfEra, date);
235 }
236
237 /**
238 * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
239 * system from the proleptic-year, month-of-year and day-of-month fields.
240 * <p>
241 * This returns a {@code JapaneseDate} with the specified fields.
242 * The day must be valid for the year and month, otherwise an exception will be thrown.
243 * <p>
244 * The Japanese proleptic year, month and day-of-month are the same as those
245 * in the ISO calendar system. They are not reset when the era changes.
246 *
247 * @param prolepticYear the Japanese proleptic-year
248 * @param month the Japanese month-of-year, from 1 to 12
249 * @param dayOfMonth the Japanese day-of-month, from 1 to 31
250 * @return the date in Japanese calendar system, not null
251 * @throws DateTimeException if the value of any field is out of range,
252 * or if the day-of-month is invalid for the month-year
253 */
254 public static JapaneseDate of(int prolepticYear, int month, int dayOfMonth) {
255 return new JapaneseDate(LocalDate.of(prolepticYear, month, dayOfMonth));
256 }
257
258 /**
259 * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
260 * system from the era, year-of-era and day-of-year fields.
261 * <p>
262 * This returns a {@code JapaneseDate} with the specified fields.
263 * The day must be valid for the year, otherwise an exception will be thrown.
264 * <p>
265 * The day-of-year in this factory is expressed relative to the start of the year-of-era.
266 * This definition changes the normal meaning of day-of-year only in those years
267 * where the year-of-era is reset to one due to a change in the era.
268 * For example:
269 * <pre>
270 * 6th Jan Showa 64 = day-of-year 6
271 * 7th Jan Showa 64 = day-of-year 7
272 * 8th Jan Heisei 1 = day-of-year 1
273 * 9th Jan Heisei 1 = day-of-year 2
274 * </pre>
275 *
276 * @param era the Japanese era, not null
277 * @param yearOfEra the Japanese year-of-era
278 * @param dayOfYear the chronology day-of-year, from 1 to 366
279 * @return the date in Japanese calendar system, not null
280 * @throws DateTimeException if the value of any field is out of range,
281 * or if the day-of-year is invalid for the year
282 */
283 static JapaneseDate ofYearDay(JapaneseEra era, int yearOfEra, int dayOfYear) {
284 Objects.requireNonNull(era, "era");
285 CalendarDate firstDay = era.getPrivateEra().getSinceDate();
286 LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
287 jdate.setEra(era.getPrivateEra());
288 if (yearOfEra == 1) {
289 jdate.setDate(yearOfEra, firstDay.getMonth(), firstDay.getDayOfMonth() + dayOfYear - 1);
290 } else {
291 jdate.setDate(yearOfEra, 1, dayOfYear);
292 }
293 JapaneseChronology.JCAL.normalize(jdate);
294 if (era.getPrivateEra() != jdate.getEra() || yearOfEra != jdate.getYear()) {
295 throw new DateTimeException("Invalid parameters");
296 }
297 LocalDate localdate = LocalDate.of(jdate.getNormalizedYear(),
298 jdate.getMonth(), jdate.getDayOfMonth());
299 return new JapaneseDate(era, yearOfEra, localdate);
300 }
301
302 /**
303 * Obtains a {@code JapaneseDate} from a temporal object.
304 * <p>
305 * This obtains a date in the Japanese calendar system based on the specified temporal.
306 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
307 * which this factory converts to an instance of {@code JapaneseDate}.
308 * <p>
309 * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
310 * field, which is standardized across calendar systems.
311 * <p>
312 * This method matches the signature of the functional interface {@link TemporalQuery}
313 * allowing it to be used as a query via method reference, {@code JapaneseDate::from}.
314 *
315 * @param temporal the temporal object to convert, not null
316 * @return the date in Japanese calendar system, not null
317 * @throws DateTimeException if unable to convert to a {@code JapaneseDate}
318 */
319 public static JapaneseDate from(TemporalAccessor temporal) {
320 return JapaneseChronology.INSTANCE.date(temporal);
321 }
322
323 //-----------------------------------------------------------------------
324 /**
325 * Creates an instance from an ISO date.
326 *
327 * @param isoDate the standard local date, validated not null
328 */
329 JapaneseDate(LocalDate isoDate) {
330 if (isoDate.isBefore(MEIJI_6_ISODATE)) {
331 throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
332 }
333 LocalGregorianCalendar.Date jdate = toPrivateJapaneseDate(isoDate);
334 this.era = JapaneseEra.toJapaneseEra(jdate.getEra());
335 this.yearOfEra = jdate.getYear();
336 this.isoDate = isoDate;
337 }
338
339 /**
340 * Constructs a {@code JapaneseDate}. This constructor does NOT validate the given parameters,
341 * and {@code era} and {@code year} must agree with {@code isoDate}.
342 *
343 * @param era the era, validated not null
344 * @param year the year-of-era, validated
345 * @param isoDate the standard local date, validated not null
346 */
347 JapaneseDate(JapaneseEra era, int year, LocalDate isoDate) {
348 if (isoDate.isBefore(MEIJI_6_ISODATE)) {
349 throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
350 }
351 this.era = era;
352 this.yearOfEra = year;
353 this.isoDate = isoDate;
354 }
355
356 //-----------------------------------------------------------------------
357 /**
358 * Gets the chronology of this date, which is the Japanese calendar system.
359 * <p>
360 * The {@code Chronology} represents the calendar system in use.
361 * The era and other fields in {@link ChronoField} are defined by the chronology.
362 *
363 * @return the Japanese chronology, not null
364 */
365 @Override
366 public JapaneseChronology getChronology() {
367 return JapaneseChronology.INSTANCE;
368 }
369
370 /**
371 * Gets the era applicable at this date.
372 * <p>
373 * The Japanese calendar system has multiple eras defined by {@link JapaneseEra}.
374 *
375 * @return the era applicable at this date, not null
376 */
377 @Override
378 public JapaneseEra getEra() {
379 return era;
380 }
381
382 /**
383 * Returns the length of the month represented by this date.
384 * <p>
385 * This returns the length of the month in days.
386 * Month lengths match those of the ISO calendar system.
387 *
388 * @return the length of the month in days
389 */
390 @Override
391 public int lengthOfMonth() {
392 return isoDate.lengthOfMonth();
393 }
394
395 @Override
396 public int lengthOfYear() {
397 Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
398 jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
399 jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
400 return jcal.getActualMaximum(Calendar.DAY_OF_YEAR);
401 }
402
403 //-----------------------------------------------------------------------
404 /**
405 * Checks if the specified field is supported.
406 * <p>
407 * This checks if this date can be queried for the specified field.
408 * If false, then calling the {@link #range(TemporalField) range} and
409 * {@link #get(TemporalField) get} methods will throw an exception.
410 * <p>
411 * If the field is a {@link ChronoField} then the query is implemented here.
412 * The supported fields are:
413 * <ul>
414 * <li>{@code DAY_OF_WEEK}
415 * <li>{@code DAY_OF_MONTH}
416 * <li>{@code DAY_OF_YEAR}
417 * <li>{@code EPOCH_DAY}
418 * <li>{@code MONTH_OF_YEAR}
419 * <li>{@code PROLEPTIC_MONTH}
420 * <li>{@code YEAR_OF_ERA}
421 * <li>{@code YEAR}
422 * <li>{@code ERA}
423 * </ul>
424 * All other {@code ChronoField} instances will return false.
425 * <p>
426 * If the field is not a {@code ChronoField}, then the result of this method
427 * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
428 * passing {@code this} as the argument.
429 * Whether the field is supported is determined by the field.
430 *
431 * @param field the field to check, null returns false
432 * @return true if the field is supported on this date, false if not
433 */
434 @Override
435 public boolean isSupported(TemporalField field) {
436 if (field == ALIGNED_DAY_OF_WEEK_IN_MONTH || field == ALIGNED_DAY_OF_WEEK_IN_YEAR ||
437 field == ALIGNED_WEEK_OF_MONTH || field == ALIGNED_WEEK_OF_YEAR) {
438 return false;
439 }
440 return super.isSupported(field);
441 }
442
443 @Override
444 public ValueRange range(TemporalField field) {
445 if (field instanceof ChronoField) {
446 if (isSupported(field)) {
447 ChronoField f = (ChronoField) field;
448 switch (f) {
449 case DAY_OF_MONTH: return ValueRange.of(1, lengthOfMonth());
450 case DAY_OF_YEAR: return ValueRange.of(1, lengthOfYear());
451 case YEAR_OF_ERA: {
452 Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
453 jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
454 jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
455 return ValueRange.of(1, jcal.getActualMaximum(Calendar.YEAR));
456 }
457 }
458 return getChronology().range(f);
459 }
460 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
461 }
462 return field.rangeRefinedBy(this);
463 }
464
465 @Override
466 public long getLong(TemporalField field) {
467 if (field instanceof ChronoField) {
468 // same as ISO:
469 // DAY_OF_WEEK, DAY_OF_MONTH, EPOCH_DAY, MONTH_OF_YEAR, PROLEPTIC_MONTH, YEAR
470 //
471 // calendar specific fields
472 // DAY_OF_YEAR, YEAR_OF_ERA, ERA
473 switch ((ChronoField) field) {
474 case ALIGNED_DAY_OF_WEEK_IN_MONTH:
475 case ALIGNED_DAY_OF_WEEK_IN_YEAR:
476 case ALIGNED_WEEK_OF_MONTH:
477 case ALIGNED_WEEK_OF_YEAR:
478 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
479 case YEAR_OF_ERA:
480 return yearOfEra;
481 case ERA:
482 return era.getValue();
483 case DAY_OF_YEAR:
484 Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
485 jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
486 jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
487 return jcal.get(Calendar.DAY_OF_YEAR);
488 }
489 return isoDate.getLong(field);
490 }
491 return field.getFrom(this);
492 }
493
494 /**
495 * Returns a {@code LocalGregorianCalendar.Date} converted from the given {@code isoDate}.
496 *
497 * @param isoDate the local date, not null
498 * @return a {@code LocalGregorianCalendar.Date}, not null
499 */
500 private static LocalGregorianCalendar.Date toPrivateJapaneseDate(LocalDate isoDate) {
501 LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
502 sun.util.calendar.Era sunEra = JapaneseEra.privateEraFrom(isoDate);
503 int year = isoDate.getYear();
504 if (sunEra != null) {
505 year -= sunEra.getSinceDate().getYear() - 1;
506 }
507 jdate.setEra(sunEra).setYear(year).setMonth(isoDate.getMonthValue()).setDayOfMonth(isoDate.getDayOfMonth());
508 JapaneseChronology.JCAL.normalize(jdate);
509 return jdate;
510 }
511
512 //-----------------------------------------------------------------------
513 @Override
514 public JapaneseDate with(TemporalField field, long newValue) {
515 if (field instanceof ChronoField) {
516 ChronoField f = (ChronoField) field;
517 if (getLong(f) == newValue) { // getLong() validates for supported fields
518 return this;
519 }
520 switch (f) {
521 case YEAR_OF_ERA:
522 case YEAR:
523 case ERA: {
524 int nvalue = getChronology().range(f).checkValidIntValue(newValue, f);
525 switch (f) {
526 case YEAR_OF_ERA:
527 return this.withYear(nvalue);
528 case YEAR:
529 return with(isoDate.withYear(nvalue));
530 case ERA: {
531 return this.withYear(JapaneseEra.of(nvalue), yearOfEra);
532 }
533 }
534 }
535 }
536 // YEAR, PROLEPTIC_MONTH and others are same as ISO
537 return with(isoDate.with(field, newValue));
538 }
539 return super.with(field, newValue);
540 }
541
542 /**
543 * {@inheritDoc}
544 * @throws DateTimeException {@inheritDoc}
545 * @throws ArithmeticException {@inheritDoc}
546 */
547 @Override
548 public JapaneseDate with(TemporalAdjuster adjuster) {
549 return super.with(adjuster);
550 }
551
552 /**
553 * {@inheritDoc}
554 * @throws DateTimeException {@inheritDoc}
555 * @throws ArithmeticException {@inheritDoc}
556 */
557 @Override
558 public JapaneseDate plus(TemporalAmount amount) {
559 return super.plus(amount);
560 }
561
562 /**
563 * {@inheritDoc}
564 * @throws DateTimeException {@inheritDoc}
565 * @throws ArithmeticException {@inheritDoc}
566 */
567 @Override
568 public JapaneseDate minus(TemporalAmount amount) {
569 return super.minus(amount);
570 }
571 //-----------------------------------------------------------------------
572 /**
573 * Returns a copy of this date with the year altered.
574 * <p>
575 * This method changes the year of the date.
576 * If the month-day is invalid for the year, then the previous valid day
577 * will be selected instead.
578 * <p>
579 * This instance is immutable and unaffected by this method call.
580 *
581 * @param era the era to set in the result, not null
582 * @param yearOfEra the year-of-era to set in the returned date
583 * @return a {@code JapaneseDate} based on this date with the requested year, never null
584 * @throws DateTimeException if {@code year} is invalid
585 */
586 private JapaneseDate withYear(JapaneseEra era, int yearOfEra) {
587 int year = JapaneseChronology.INSTANCE.prolepticYear(era, yearOfEra);
588 return with(isoDate.withYear(year));
589 }
590
591 /**
592 * Returns a copy of this date with the year-of-era altered.
593 * <p>
594 * This method changes the year-of-era of the date.
595 * If the month-day is invalid for the year, then the previous valid day
596 * will be selected instead.
597 * <p>
598 * This instance is immutable and unaffected by this method call.
599 *
600 * @param year the year to set in the returned date
601 * @return a {@code JapaneseDate} based on this date with the requested year-of-era, never null
602 * @throws DateTimeException if {@code year} is invalid
603 */
604 private JapaneseDate withYear(int year) {
605 return withYear(getEra(), year);
606 }
607
608 //-----------------------------------------------------------------------
609 @Override
610 JapaneseDate plusYears(long years) {
611 return with(isoDate.plusYears(years));
612 }
613
614 @Override
615 JapaneseDate plusMonths(long months) {
616 return with(isoDate.plusMonths(months));
617 }
618
619 @Override
620 JapaneseDate plusWeeks(long weeksToAdd) {
621 return with(isoDate.plusWeeks(weeksToAdd));
622 }
623
624 @Override
625 JapaneseDate plusDays(long days) {
626 return with(isoDate.plusDays(days));
627 }
628
629 @Override
630 public JapaneseDate plus(long amountToAdd, TemporalUnit unit) {
631 return super.plus(amountToAdd, unit);
632 }
633
634 @Override
635 public JapaneseDate minus(long amountToAdd, TemporalUnit unit) {
636 return super.minus(amountToAdd, unit);
637 }
638
639 @Override
640 JapaneseDate minusYears(long yearsToSubtract) {
641 return super.minusYears(yearsToSubtract);
642 }
643
644 @Override
645 JapaneseDate minusMonths(long monthsToSubtract) {
646 return super.minusMonths(monthsToSubtract);
647 }
648
649 @Override
650 JapaneseDate minusWeeks(long weeksToSubtract) {
651 return super.minusWeeks(weeksToSubtract);
652 }
653
654 @Override
655 JapaneseDate minusDays(long daysToSubtract) {
656 return super.minusDays(daysToSubtract);
657 }
658
659 private JapaneseDate with(LocalDate newDate) {
660 return (newDate.equals(isoDate) ? this : new JapaneseDate(newDate));
661 }
662
663 @Override // for javadoc and covariant return type
664 @SuppressWarnings("unchecked")
665 public final ChronoLocalDateTime<JapaneseDate> atTime(LocalTime localTime) {
666 return (ChronoLocalDateTime<JapaneseDate>)super.atTime(localTime);
667 }
668
669 @Override
670 public ChronoPeriod until(ChronoLocalDate endDate) {
671 Period period = isoDate.until(endDate);
672 return getChronology().period(period.getYears(), period.getMonths(), period.getDays());
673 }
674
675 @Override // override for performance
676 public long toEpochDay() {
677 return isoDate.toEpochDay();
678 }
679
680 //-------------------------------------------------------------------------
681 /**
682 * Compares this date to another date, including the chronology.
683 * <p>
684 * Compares this {@code JapaneseDate} with another ensuring that the date is the same.
685 * <p>
686 * Only objects of type {@code JapaneseDate} are compared, other types return false.
687 * To compare the dates of two {@code TemporalAccessor} instances, including dates
688 * in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
689 *
690 * @param obj the object to check, null returns false
691 * @return true if this is equal to the other date
692 */
693 @Override // override for performance
694 public boolean equals(Object obj) {
695 if (this == obj) {
696 return true;
697 }
698 if (obj instanceof JapaneseDate) {
699 JapaneseDate otherDate = (JapaneseDate) obj;
700 return this.isoDate.equals(otherDate.isoDate);
701 }
702 return false;
703 }
704
705 /**
706 * A hash code for this date.
707 *
708 * @return a suitable hash code based only on the Chronology and the date
709 */
710 @Override // override for performance
711 public int hashCode() {
712 return getChronology().getId().hashCode() ^ isoDate.hashCode();
713 }
714
715 //-----------------------------------------------------------------------
716 /**
717 * Defend against malicious streams.
718 *
719 * @param s the stream to read
720 * @throws InvalidObjectException always
721 */
722 private void readObject(ObjectInputStream s) throws InvalidObjectException {
723 throw new InvalidObjectException("Deserialization via serialization delegate");
724 }
725
726 /**
727 * Writes the object using a
728 * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
729 * @serialData
730 * <pre>
731 * out.writeByte(4); // identifies a JapaneseDate
732 * out.writeInt(get(YEAR));
733 * out.writeByte(get(MONTH_OF_YEAR));
734 * out.writeByte(get(DAY_OF_MONTH));
735 * </pre>
736 *
737 * @return the instance of {@code Ser}, not null
738 */
739 private Object writeReplace() {
740 return new Ser(Ser.JAPANESE_DATE_TYPE, this);
741 }
742
743 void writeExternal(DataOutput out) throws IOException {
744 // JapaneseChronology is implicit in the JAPANESE_DATE_TYPE
745 out.writeInt(get(YEAR));
746 out.writeByte(get(MONTH_OF_YEAR));
747 out.writeByte(get(DAY_OF_MONTH));
748 }
749
750 static JapaneseDate readExternal(DataInput in) throws IOException {
751 int year = in.readInt();
752 int month = in.readByte();
753 int dayOfMonth = in.readByte();
754 return JapaneseChronology.INSTANCE.date(year, month, dayOfMonth);
755 }
756
757 }