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