1 /*
2 * Copyright (c) 2012, 2019, 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.IOException;
68 import java.io.InvalidObjectException;
69 import java.io.ObjectInput;
70 import java.io.ObjectInputStream;
71 import java.io.ObjectOutput;
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.ZoneId;
78 import java.time.temporal.ChronoField;
79 import java.time.temporal.TemporalAccessor;
80 import java.time.temporal.TemporalAdjuster;
81 import java.time.temporal.TemporalAmount;
82 import java.time.temporal.TemporalField;
83 import java.time.temporal.TemporalQuery;
84 import java.time.temporal.TemporalUnit;
85 import java.time.temporal.UnsupportedTemporalTypeException;
86 import java.time.temporal.ValueRange;
87
88 /**
89 * A date in the Hijrah calendar system.
90 * <p>
91 * This date operates using one of several variants of the
92 * {@linkplain HijrahChronology Hijrah calendar}.
93 * <p>
94 * The Hijrah calendar has a different total of days in a year than
95 * Gregorian calendar, and the length of each month is based on the period
96 * of a complete revolution of the moon around the earth
97 * (as between successive new moons).
98 * Refer to the {@link HijrahChronology} for details of supported variants.
99 * <p>
100 * Each HijrahDate is created bound to a particular HijrahChronology,
101 * The same chronology is propagated to each HijrahDate computed from the date.
102 * To use a different Hijrah variant, its HijrahChronology can be used
103 * to create new HijrahDate instances.
104 * Alternatively, the {@link #withVariant} method can be used to convert
105 * to a new HijrahChronology.
106 * <p>
107 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
108 * class; programmers should treat instances that are
109 * {@linkplain #equals(Object) equal} as interchangeable and should not
110 * use instances for synchronization, or unpredictable behavior may
111 * occur. For example, in a future release, synchronization may fail.
112 * The {@code equals} method should be used for comparisons.
113 *
114 * @implSpec
115 * This class is immutable and thread-safe.
116 *
117 * @since 1.8
118 */
119 @jdk.internal.ValueBased
120 public final class HijrahDate
121 extends ChronoLocalDateImpl<HijrahDate>
122 implements ChronoLocalDate, Serializable {
123
124 /**
125 * Serialization version.
126 */
127 @java.io.Serial
128 private static final long serialVersionUID = -5207853542612002020L;
129 /**
130 * The Chronology of this HijrahDate.
131 */
132 private final transient HijrahChronology chrono;
133 /**
134 * The proleptic year.
135 */
136 private final transient int prolepticYear;
137 /**
138 * The month-of-year.
139 */
140 private final transient int monthOfYear;
141 /**
142 * The day-of-month.
143 */
144 private final transient int dayOfMonth;
145
146 //-------------------------------------------------------------------------
147 /**
148 * Obtains an instance of {@code HijrahDate} from the Hijrah proleptic year,
149 * month-of-year and day-of-month.
150 *
151 * @param prolepticYear the proleptic year to represent in the Hijrah calendar
152 * @param monthOfYear the month-of-year to represent, from 1 to 12
153 * @param dayOfMonth the day-of-month to represent, from 1 to 30
154 * @return the Hijrah date, never null
155 * @throws DateTimeException if the value of any field is out of range
156 */
157 static HijrahDate of(HijrahChronology chrono, int prolepticYear, int monthOfYear, int dayOfMonth) {
158 return new HijrahDate(chrono, prolepticYear, monthOfYear, dayOfMonth);
159 }
160
161 /**
162 * Returns a HijrahDate for the chronology and epochDay.
163 * @param chrono The Hijrah chronology
164 * @param epochDay the epoch day
165 * @return a HijrahDate for the epoch day; non-null
166 */
167 static HijrahDate ofEpochDay(HijrahChronology chrono, long epochDay) {
168 return new HijrahDate(chrono, epochDay);
169 }
170
171 //-----------------------------------------------------------------------
172 /**
173 * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
174 * in the default time-zone.
175 * <p>
176 * This will query the {@link Clock#systemDefaultZone() system clock} in the default
177 * time-zone to obtain the current date.
178 * <p>
179 * Using this method will prevent the ability to use an alternate clock for testing
180 * because the clock is hard-coded.
181 *
182 * @return the current date using the system clock and default time-zone, not null
183 */
184 public static HijrahDate now() {
185 return now(Clock.systemDefaultZone());
186 }
187
188 /**
189 * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
190 * in the specified time-zone.
191 * <p>
192 * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
193 * Specifying the time-zone avoids dependence on the default time-zone.
194 * <p>
195 * Using this method will prevent the ability to use an alternate clock for testing
196 * because the clock is hard-coded.
197 *
198 * @param zone the zone ID to use, not null
199 * @return the current date using the system clock, not null
200 */
201 public static HijrahDate now(ZoneId zone) {
202 return now(Clock.system(zone));
203 }
204
205 /**
206 * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
207 * from the specified clock.
208 * <p>
209 * This will query the specified clock to obtain the current date - today.
210 * Using this method allows the use of an alternate clock for testing.
211 * The alternate clock may be introduced using {@linkplain Clock dependency injection}.
212 *
213 * @param clock the clock to use, not null
214 * @return the current date, not null
215 * @throws DateTimeException if the current date cannot be obtained
216 */
217 public static HijrahDate now(Clock clock) {
218 return HijrahDate.ofEpochDay(HijrahChronology.INSTANCE, LocalDate.now(clock).toEpochDay());
219 }
220
221 /**
222 * Obtains a {@code HijrahDate} of the Islamic Umm Al-Qura calendar
223 * from the proleptic-year, month-of-year and day-of-month fields.
224 * <p>
225 * This returns a {@code HijrahDate} with the specified fields.
226 * The day must be valid for the year and month, otherwise an exception will be thrown.
227 *
228 * @param prolepticYear the Hijrah proleptic-year
229 * @param month the Hijrah month-of-year, from 1 to 12
230 * @param dayOfMonth the Hijrah day-of-month, from 1 to 30
231 * @return the date in Hijrah calendar system, not null
232 * @throws DateTimeException if the value of any field is out of range,
233 * or if the day-of-month is invalid for the month-year
234 */
235 public static HijrahDate of(int prolepticYear, int month, int dayOfMonth) {
236 return HijrahChronology.INSTANCE.date(prolepticYear, month, dayOfMonth);
237 }
238
239 /**
240 * Obtains a {@code HijrahDate} of the Islamic Umm Al-Qura calendar from a temporal object.
241 * <p>
242 * This obtains a date in the Hijrah calendar system based on the specified temporal.
243 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
244 * which this factory converts to an instance of {@code HijrahDate}.
245 * <p>
246 * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
247 * field, which is standardized across calendar systems.
248 * <p>
249 * This method matches the signature of the functional interface {@link TemporalQuery}
250 * allowing it to be used as a query via method reference, {@code HijrahDate::from}.
251 *
252 * @param temporal the temporal object to convert, not null
253 * @return the date in Hijrah calendar system, not null
254 * @throws DateTimeException if unable to convert to a {@code HijrahDate}
255 */
256 public static HijrahDate from(TemporalAccessor temporal) {
257 return HijrahChronology.INSTANCE.date(temporal);
258 }
259
260 //-----------------------------------------------------------------------
261 /**
262 * Constructs an {@code HijrahDate} with the proleptic-year, month-of-year and
263 * day-of-month fields.
264 *
265 * @param chrono The chronology to create the date with
266 * @param prolepticYear the proleptic year
267 * @param monthOfYear the month of year
268 * @param dayOfMonth the day of month
269 */
270 private HijrahDate(HijrahChronology chrono, int prolepticYear, int monthOfYear, int dayOfMonth) {
271 // Computing the Gregorian day checks the valid ranges
272 chrono.getEpochDay(prolepticYear, monthOfYear, dayOfMonth);
273
274 this.chrono = chrono;
275 this.prolepticYear = prolepticYear;
276 this.monthOfYear = monthOfYear;
277 this.dayOfMonth = dayOfMonth;
278 }
279
280 /**
281 * Constructs an instance with the Epoch Day.
282 *
283 * @param epochDay the epochDay
284 */
285 private HijrahDate(HijrahChronology chrono, long epochDay) {
286 int[] dateInfo = chrono.getHijrahDateInfo((int)epochDay);
287
288 this.chrono = chrono;
289 this.prolepticYear = dateInfo[0];
290 this.monthOfYear = dateInfo[1];
291 this.dayOfMonth = dateInfo[2];
292 }
293
294 //-----------------------------------------------------------------------
295 /**
296 * Gets the chronology of this date, which is the Hijrah calendar system.
297 * <p>
298 * The {@code Chronology} represents the calendar system in use.
299 * The era and other fields in {@link ChronoField} are defined by the chronology.
300 *
301 * @return the Hijrah chronology, not null
302 */
303 @Override
304 public HijrahChronology getChronology() {
305 return chrono;
306 }
307
308 /**
309 * Gets the era applicable at this date.
310 * <p>
311 * The Hijrah calendar system has one era, 'AH',
312 * defined by {@link HijrahEra}.
313 *
314 * @return the era applicable at this date, not null
315 */
316 @Override
317 public HijrahEra getEra() {
318 return HijrahEra.AH;
319 }
320
321 /**
322 * Returns the length of the month represented by this date.
323 * <p>
324 * This returns the length of the month in days.
325 * Month lengths in the Hijrah calendar system vary between 29 and 30 days.
326 *
327 * @return the length of the month in days
328 */
329 @Override
330 public int lengthOfMonth() {
331 return chrono.getMonthLength(prolepticYear, monthOfYear);
332 }
333
334 /**
335 * Returns the length of the year represented by this date.
336 * <p>
337 * This returns the length of the year in days.
338 * A Hijrah calendar system year is typically shorter than
339 * that of the ISO calendar system.
340 *
341 * @return the length of the year in days
342 */
343 @Override
344 public int lengthOfYear() {
345 return chrono.getYearLength(prolepticYear);
346 }
347
348 //-----------------------------------------------------------------------
349 @Override
350 public ValueRange range(TemporalField field) {
351 if (field instanceof ChronoField) {
352 if (isSupported(field)) {
353 ChronoField f = (ChronoField) field;
354 return switch (f) {
355 case DAY_OF_MONTH -> ValueRange.of(1, lengthOfMonth());
356 case DAY_OF_YEAR -> ValueRange.of(1, lengthOfYear());
357 case ALIGNED_WEEK_OF_MONTH -> ValueRange.of(1, 5); // TODO
358 // TODO does the limited range of valid years cause years to
359 // start/end part way through? that would affect range
360 default -> getChronology().range(f);
361 };
362 }
363 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
364 }
365 return field.rangeRefinedBy(this);
366 }
367
368 @Override
369 public long getLong(TemporalField field) {
370 if (field instanceof ChronoField) {
371 return switch ((ChronoField) field) {
372 case DAY_OF_WEEK -> getDayOfWeek();
373 case ALIGNED_DAY_OF_WEEK_IN_MONTH -> ((dayOfMonth - 1) % 7) + 1;
374 case ALIGNED_DAY_OF_WEEK_IN_YEAR -> ((getDayOfYear() - 1) % 7) + 1;
375 case DAY_OF_MONTH -> this.dayOfMonth;
376 case DAY_OF_YEAR -> this.getDayOfYear();
377 case EPOCH_DAY -> toEpochDay();
378 case ALIGNED_WEEK_OF_MONTH -> ((dayOfMonth - 1) / 7) + 1;
379 case ALIGNED_WEEK_OF_YEAR -> ((getDayOfYear() - 1) / 7) + 1;
380 case MONTH_OF_YEAR -> monthOfYear;
381 case PROLEPTIC_MONTH -> getProlepticMonth();
382 case YEAR_OF_ERA -> prolepticYear;
383 case YEAR -> prolepticYear;
384 case ERA -> getEraValue();
385 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
386 };
387 }
388 return field.getFrom(this);
389 }
390
391 private long getProlepticMonth() {
392 return prolepticYear * 12L + monthOfYear - 1;
393 }
394
395 @Override
396 public HijrahDate with(TemporalField field, long newValue) {
397 if (field instanceof ChronoField chronoField) {
398 // not using checkValidIntValue so EPOCH_DAY and PROLEPTIC_MONTH work
399 chrono.range(chronoField).checkValidValue(newValue, chronoField); // TODO: validate value
400 int nvalue = (int) newValue;
401 return switch (chronoField) {
402 case DAY_OF_WEEK -> plusDays(newValue - getDayOfWeek());
403 case ALIGNED_DAY_OF_WEEK_IN_MONTH -> plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_MONTH));
404 case ALIGNED_DAY_OF_WEEK_IN_YEAR -> plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_YEAR));
405 case DAY_OF_MONTH -> resolvePreviousValid(prolepticYear, monthOfYear, nvalue);
406 case DAY_OF_YEAR -> plusDays(Math.min(nvalue, lengthOfYear()) - getDayOfYear());
407 case EPOCH_DAY -> new HijrahDate(chrono, newValue);
408 case ALIGNED_WEEK_OF_MONTH -> plusDays((newValue - getLong(ALIGNED_WEEK_OF_MONTH)) * 7);
409 case ALIGNED_WEEK_OF_YEAR -> plusDays((newValue - getLong(ALIGNED_WEEK_OF_YEAR)) * 7);
410 case MONTH_OF_YEAR -> resolvePreviousValid(prolepticYear, nvalue, dayOfMonth);
411 case PROLEPTIC_MONTH -> plusMonths(newValue - getProlepticMonth());
412 case YEAR_OF_ERA -> resolvePreviousValid(prolepticYear >= 1 ? nvalue : 1 - nvalue, monthOfYear, dayOfMonth);
413 case YEAR -> resolvePreviousValid(nvalue, monthOfYear, dayOfMonth);
414 case ERA -> resolvePreviousValid(1 - prolepticYear, monthOfYear, dayOfMonth);
415 default -> throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
416 };
417 }
418 return super.with(field, newValue);
419 }
420
421 private HijrahDate resolvePreviousValid(int prolepticYear, int month, int day) {
422 int monthDays = chrono.getMonthLength(prolepticYear, month);
423 if (day > monthDays) {
424 day = monthDays;
425 }
426 return HijrahDate.of(chrono, prolepticYear, month, day);
427 }
428
429 /**
430 * {@inheritDoc}
431 * @throws DateTimeException if unable to make the adjustment.
432 * For example, if the adjuster requires an ISO chronology
433 * @throws ArithmeticException {@inheritDoc}
434 */
435 @Override
436 public HijrahDate with(TemporalAdjuster adjuster) {
437 return super.with(adjuster);
438 }
439
440 /**
441 * Returns a {@code HijrahDate} with the Chronology requested.
442 * <p>
443 * The year, month, and day are checked against the new requested
444 * HijrahChronology. If the chronology has a shorter month length
445 * for the month, the day is reduced to be the last day of the month.
446 *
447 * @param chronology the new HijrahChonology, non-null
448 * @return a HijrahDate with the requested HijrahChronology, non-null
449 */
450 public HijrahDate withVariant(HijrahChronology chronology) {
451 if (chrono == chronology) {
452 return this;
453 }
454 // Like resolvePreviousValid the day is constrained to stay in the same month
455 int monthDays = chronology.getDayOfYear(prolepticYear, monthOfYear);
456 return HijrahDate.of(chronology, prolepticYear, monthOfYear,(dayOfMonth > monthDays) ? monthDays : dayOfMonth );
457 }
458
459 /**
460 * {@inheritDoc}
461 * @throws DateTimeException {@inheritDoc}
462 * @throws ArithmeticException {@inheritDoc}
463 */
464 @Override
465 public HijrahDate plus(TemporalAmount amount) {
466 return super.plus(amount);
467 }
468
469 /**
470 * {@inheritDoc}
471 * @throws DateTimeException {@inheritDoc}
472 * @throws ArithmeticException {@inheritDoc}
473 */
474 @Override
475 public HijrahDate minus(TemporalAmount amount) {
476 return super.minus(amount);
477 }
478
479 @Override
480 public long toEpochDay() {
481 return chrono.getEpochDay(prolepticYear, monthOfYear, dayOfMonth);
482 }
483
484 /**
485 * Gets the day-of-year field.
486 * <p>
487 * This method returns the primitive {@code int} value for the day-of-year.
488 *
489 * @return the day-of-year
490 */
491 private int getDayOfYear() {
492 return chrono.getDayOfYear(prolepticYear, monthOfYear) + dayOfMonth;
493 }
494
495 /**
496 * Gets the day-of-week value.
497 *
498 * @return the day-of-week; computed from the epochday
499 */
500 private int getDayOfWeek() {
501 int dow0 = Math.floorMod(toEpochDay() + 3, 7);
502 return dow0 + 1;
503 }
504
505 /**
506 * Gets the Era of this date.
507 *
508 * @return the Era of this date; computed from epochDay
509 */
510 private int getEraValue() {
511 return (prolepticYear > 1 ? 1 : 0);
512 }
513
514 //-----------------------------------------------------------------------
515 /**
516 * Checks if the year is a leap year, according to the Hijrah calendar system rules.
517 *
518 * @return true if this date is in a leap year
519 */
520 @Override
521 public boolean isLeapYear() {
522 return chrono.isLeapYear(prolepticYear);
523 }
524
525 //-----------------------------------------------------------------------
526 @Override
527 HijrahDate plusYears(long years) {
528 if (years == 0) {
529 return this;
530 }
531 int newYear = Math.addExact(this.prolepticYear, (int)years);
532 return resolvePreviousValid(newYear, monthOfYear, dayOfMonth);
533 }
534
535 @Override
536 HijrahDate plusMonths(long monthsToAdd) {
537 if (monthsToAdd == 0) {
538 return this;
539 }
540 long monthCount = prolepticYear * 12L + (monthOfYear - 1);
541 long calcMonths = monthCount + monthsToAdd; // safe overflow
542 int newYear = chrono.checkValidYear(Math.floorDiv(calcMonths, 12L));
543 int newMonth = (int)Math.floorMod(calcMonths, 12L) + 1;
544 return resolvePreviousValid(newYear, newMonth, dayOfMonth);
545 }
546
547 @Override
548 HijrahDate plusWeeks(long weeksToAdd) {
549 return super.plusWeeks(weeksToAdd);
550 }
551
552 @Override
553 HijrahDate plusDays(long days) {
554 return new HijrahDate(chrono, toEpochDay() + days);
555 }
556
557 @Override
558 public HijrahDate plus(long amountToAdd, TemporalUnit unit) {
559 return super.plus(amountToAdd, unit);
560 }
561
562 @Override
563 public HijrahDate minus(long amountToSubtract, TemporalUnit unit) {
564 return super.minus(amountToSubtract, unit);
565 }
566
567 @Override
568 HijrahDate minusYears(long yearsToSubtract) {
569 return super.minusYears(yearsToSubtract);
570 }
571
572 @Override
573 HijrahDate minusMonths(long monthsToSubtract) {
574 return super.minusMonths(monthsToSubtract);
575 }
576
577 @Override
578 HijrahDate minusWeeks(long weeksToSubtract) {
579 return super.minusWeeks(weeksToSubtract);
580 }
581
582 @Override
583 HijrahDate minusDays(long daysToSubtract) {
584 return super.minusDays(daysToSubtract);
585 }
586
587 @Override // for javadoc and covariant return type
588 @SuppressWarnings("unchecked")
589 public final ChronoLocalDateTime<HijrahDate> atTime(LocalTime localTime) {
590 return (ChronoLocalDateTime<HijrahDate>)super.atTime(localTime);
591 }
592
593 @Override
594 public ChronoPeriod until(ChronoLocalDate endDate) {
595 // TODO: untested
596 HijrahDate end = getChronology().date(endDate);
597 long totalMonths = (end.prolepticYear - this.prolepticYear) * 12 + (end.monthOfYear - this.monthOfYear); // safe
598 int days = end.dayOfMonth - this.dayOfMonth;
599 if (totalMonths > 0 && days < 0) {
600 totalMonths--;
601 HijrahDate calcDate = this.plusMonths(totalMonths);
602 days = (int) (end.toEpochDay() - calcDate.toEpochDay()); // safe
603 } else if (totalMonths < 0 && days > 0) {
604 totalMonths++;
605 days -= end.lengthOfMonth();
606 }
607 long years = totalMonths / 12; // safe
608 int months = (int) (totalMonths % 12); // safe
609 return getChronology().period(Math.toIntExact(years), months, days);
610 }
611
612 //-------------------------------------------------------------------------
613 /**
614 * Compares this date to another date, including the chronology.
615 * <p>
616 * Compares this {@code HijrahDate} with another ensuring that the date is the same.
617 * <p>
618 * Only objects of type {@code HijrahDate} are compared, other types return false.
619 * To compare the dates of two {@code TemporalAccessor} instances, including dates
620 * in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
621 *
622 * @param obj the object to check, null returns false
623 * @return true if this is equal to the other date and the Chronologies are equal
624 */
625 @Override // override for performance
626 public boolean equals(Object obj) {
627 if (this == obj) {
628 return true;
629 }
630 return (obj instanceof HijrahDate otherDate)
631 && prolepticYear == otherDate.prolepticYear
632 && this.monthOfYear == otherDate.monthOfYear
633 && this.dayOfMonth == otherDate.dayOfMonth
634 && getChronology().equals(otherDate.getChronology());
635 }
636
637 /**
638 * A hash code for this date.
639 *
640 * @return a suitable hash code based only on the Chronology and the date
641 */
642 @Override // override for performance
643 public int hashCode() {
644 int yearValue = prolepticYear;
645 int monthValue = monthOfYear;
646 int dayValue = dayOfMonth;
647 return getChronology().getId().hashCode() ^ (yearValue & 0xFFFFF800)
648 ^ ((yearValue << 11) + (monthValue << 6) + (dayValue));
649 }
650
651 //-----------------------------------------------------------------------
652 /**
653 * Defend against malicious streams.
654 *
655 * @param s the stream to read
656 * @throws InvalidObjectException always
657 */
658 @java.io.Serial
659 private void readObject(ObjectInputStream s) throws InvalidObjectException {
660 throw new InvalidObjectException("Deserialization via serialization delegate");
661 }
662
663 /**
664 * Writes the object using a
665 * <a href="{@docRoot}/serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
666 * @serialData
667 * <pre>
668 * out.writeByte(6); // identifies a HijrahDate
669 * out.writeObject(chrono); // the HijrahChronology variant
670 * out.writeInt(get(YEAR));
671 * out.writeByte(get(MONTH_OF_YEAR));
672 * out.writeByte(get(DAY_OF_MONTH));
673 * </pre>
674 *
675 * @return the instance of {@code Ser}, not null
676 */
677 @java.io.Serial
678 private Object writeReplace() {
679 return new Ser(Ser.HIJRAH_DATE_TYPE, this);
680 }
681
682 void writeExternal(ObjectOutput out) throws IOException {
683 // HijrahChronology is implicit in the Hijrah_DATE_TYPE
684 out.writeObject(getChronology());
685 out.writeInt(get(YEAR));
686 out.writeByte(get(MONTH_OF_YEAR));
687 out.writeByte(get(DAY_OF_MONTH));
688 }
689
690 static HijrahDate readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
691 HijrahChronology chrono = (HijrahChronology) in.readObject();
692 int year = in.readInt();
693 int month = in.readByte();
694 int dayOfMonth = in.readByte();
695 return chrono.date(year, month, dayOfMonth);
696 }
697
698 }