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 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file:
31 *
32 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
33 *
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions are met:
38 *
39 * * Redistributions of source code must retain the above copyright notice,
40 * this list of conditions and the following disclaimer.
41 *
42 * * Redistributions in binary form must reproduce the above copyright notice,
43 * this list of conditions and the following disclaimer in the documentation
44 * and/or other materials provided with the distribution.
45 *
46 * * Neither the name of JSR-310 nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 package java.time.chrono;
63
64 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
65 import static java.time.temporal.ChronoField.ERA;
66 import static java.time.temporal.ChronoField.HOUR_OF_DAY;
67 import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;
68 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
69 import static java.time.temporal.ChronoField.PROLEPTIC_MONTH;
70 import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;
71 import static java.time.temporal.ChronoField.YEAR;
72 import static java.time.temporal.ChronoField.YEAR_OF_ERA;
73
74 import java.io.InvalidObjectException;
75 import java.io.ObjectInputStream;
76 import java.io.Serializable;
77 import java.time.Clock;
78 import java.time.DateTimeException;
79 import java.time.Instant;
80 import java.time.LocalDate;
81 import java.time.LocalDateTime;
82 import java.time.Month;
83 import java.time.Period;
84 import java.time.Year;
85 import java.time.ZonedDateTime;
86 import java.time.ZoneId;
87 import java.time.ZoneOffset;
88 import java.time.format.ResolverStyle;
89 import java.time.temporal.ChronoField;
90 import java.time.temporal.TemporalAccessor;
91 import java.time.temporal.TemporalField;
92 import java.time.temporal.ValueRange;
93 import java.util.List;
94 import java.util.Locale;
95 import java.util.Map;
96 import java.util.Objects;
97
98 /**
99 * The ISO calendar system.
100 * <p>
101 * This chronology defines the rules of the ISO calendar system.
102 * This calendar system is based on the ISO-8601 standard, which is the
103 * <i>de facto</i> world calendar.
104 * <p>
105 * The fields are defined as follows:
106 * <ul>
107 * <li>era - There are two eras, 'Current Era' (CE) and 'Before Current Era' (BCE).
108 * <li>year-of-era - The year-of-era is the same as the proleptic-year for the current CE era.
109 * For the BCE era before the ISO epoch the year increases from 1 upwards as time goes backwards.
110 * <li>proleptic-year - The proleptic year is the same as the year-of-era for the
111 * current era. For the previous era, years have zero, then negative values.
112 * <li>month-of-year - There are 12 months in an ISO year, numbered from 1 to 12.
113 * <li>day-of-month - There are between 28 and 31 days in each of the ISO month, numbered from 1 to 31.
114 * Months 4, 6, 9 and 11 have 30 days, Months 1, 3, 5, 7, 8, 10 and 12 have 31 days.
115 * Month 2 has 28 days, or 29 in a leap year.
116 * <li>day-of-year - There are 365 days in a standard ISO year and 366 in a leap year.
117 * The days are numbered from 1 to 365 or 1 to 366.
118 * <li>leap-year - Leap years occur every 4 years, except where the year is divisble by 100 and not divisble by 400.
119 * </ul>
120 *
121 * @implSpec
122 * This class is immutable and thread-safe.
123 *
124 * @since 1.8
125 */
126 public final class IsoChronology extends AbstractChronology implements Serializable {
127
128 /**
129 * Singleton instance of the ISO chronology.
130 */
131 public static final IsoChronology INSTANCE = new IsoChronology();
132
133 /**
134 * Serialization version.
135 */
136 private static final long serialVersionUID = -1440403870442975015L;
137
138 private static final long DAYS_0000_TO_1970 = (146097 * 5L) - (30L * 365L + 7L); // taken from LocalDate
139
140 /**
141 * Restricted constructor.
142 */
143 private IsoChronology() {
144 }
145
146 //-----------------------------------------------------------------------
147 /**
148 * Gets the ID of the chronology - 'ISO'.
149 * <p>
150 * The ID uniquely identifies the {@code Chronology}.
151 * It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
152 *
153 * @return the chronology ID - 'ISO'
154 * @see #getCalendarType()
155 */
156 @Override
157 public String getId() {
158 return "ISO";
159 }
160
161 /**
162 * Gets the calendar type of the underlying calendar system - 'iso8601'.
163 * <p>
164 * The calendar type is an identifier defined by the
165 * <em>Unicode Locale Data Markup Language (LDML)</em> specification.
166 * It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
167 * It can also be used as part of a locale, accessible via
168 * {@link Locale#getUnicodeLocaleType(String)} with the key 'ca'.
169 *
170 * @return the calendar system type - 'iso8601'
171 * @see #getId()
172 */
173 @Override
174 public String getCalendarType() {
175 return "iso8601";
176 }
177
178 //-----------------------------------------------------------------------
179 /**
180 * Obtains an ISO local date from the era, year-of-era, month-of-year
181 * and day-of-month fields.
182 *
183 * @param era the ISO era, not null
184 * @param yearOfEra the ISO year-of-era
185 * @param month the ISO month-of-year
186 * @param dayOfMonth the ISO day-of-month
187 * @return the ISO local date, not null
188 * @throws DateTimeException if unable to create the date
189 * @throws ClassCastException if the type of {@code era} is not {@code IsoEra}
190 */
191 @Override // override with covariant return type
192 public LocalDate date(Era era, int yearOfEra, int month, int dayOfMonth) {
193 return date(prolepticYear(era, yearOfEra), month, dayOfMonth);
194 }
195
196 /**
197 * Obtains an ISO local date from the proleptic-year, month-of-year
198 * and day-of-month fields.
199 * <p>
200 * This is equivalent to {@link LocalDate#of(int, int, int)}.
201 *
202 * @param prolepticYear the ISO proleptic-year
203 * @param month the ISO month-of-year
204 * @param dayOfMonth the ISO day-of-month
205 * @return the ISO local date, not null
206 * @throws DateTimeException if unable to create the date
207 */
208 @Override // override with covariant return type
209 public LocalDate date(int prolepticYear, int month, int dayOfMonth) {
210 return LocalDate.of(prolepticYear, month, dayOfMonth);
211 }
212
213 /**
214 * Obtains an ISO local date from the era, year-of-era and day-of-year fields.
215 *
216 * @param era the ISO era, not null
217 * @param yearOfEra the ISO year-of-era
218 * @param dayOfYear the ISO day-of-year
219 * @return the ISO local date, not null
220 * @throws DateTimeException if unable to create the date
221 */
222 @Override // override with covariant return type
223 public LocalDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {
224 return dateYearDay(prolepticYear(era, yearOfEra), dayOfYear);
225 }
226
227 /**
228 * Obtains an ISO local date from the proleptic-year and day-of-year fields.
229 * <p>
230 * This is equivalent to {@link LocalDate#ofYearDay(int, int)}.
231 *
232 * @param prolepticYear the ISO proleptic-year
233 * @param dayOfYear the ISO day-of-year
234 * @return the ISO local date, not null
235 * @throws DateTimeException if unable to create the date
236 */
237 @Override // override with covariant return type
238 public LocalDate dateYearDay(int prolepticYear, int dayOfYear) {
239 return LocalDate.ofYearDay(prolepticYear, dayOfYear);
240 }
241
242 /**
243 * Obtains an ISO local date from the epoch-day.
244 * <p>
245 * This is equivalent to {@link LocalDate#ofEpochDay(long)}.
246 *
247 * @param epochDay the epoch day
248 * @return the ISO local date, not null
249 * @throws DateTimeException if unable to create the date
250 */
251 @Override // override with covariant return type
252 public LocalDate dateEpochDay(long epochDay) {
253 return LocalDate.ofEpochDay(epochDay);
254 }
255
256 //-----------------------------------------------------------------------
257 /**
258 * Obtains an ISO local date from another date-time object.
259 * <p>
260 * This is equivalent to {@link LocalDate#from(TemporalAccessor)}.
261 *
262 * @param temporal the date-time object to convert, not null
263 * @return the ISO local date, not null
264 * @throws DateTimeException if unable to create the date
265 */
266 @Override // override with covariant return type
267 public LocalDate date(TemporalAccessor temporal) {
268 return LocalDate.from(temporal);
269 }
270
271 //-----------------------------------------------------------------------
272 /**
273 * Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z.
274 * <p>
275 * The number of seconds is calculated using the year,
276 * month, day-of-month, hour, minute, second, and zoneOffset.
277 *
278 * @param prolepticYear the year, from MIN_YEAR to MAX_YEAR
279 * @param month the month-of-year, from 1 to 12
280 * @param dayOfMonth the day-of-month, from 1 to 31
281 * @param hour the hour-of-day, from 0 to 23
282 * @param minute the minute-of-hour, from 0 to 59
283 * @param second the second-of-minute, from 0 to 59
284 * @param zoneOffset the zone offset, not null
285 * @return the number of seconds relative to 1970-01-01T00:00:00Z, may be negative
286 * @throws DateTimeException if the value of any argument is out of range,
287 * or if the day-of-month is invalid for the month-of-year
288 * @since 9
289 */
290 @Override
291 public long epochSecond(int prolepticYear, int month, int dayOfMonth,
292 int hour, int minute, int second, ZoneOffset zoneOffset) {
293 YEAR.checkValidValue(prolepticYear);
294 MONTH_OF_YEAR.checkValidValue(month);
295 DAY_OF_MONTH.checkValidValue(dayOfMonth);
296 HOUR_OF_DAY.checkValidValue(hour);
297 MINUTE_OF_HOUR.checkValidValue(minute);
298 SECOND_OF_MINUTE.checkValidValue(second);
299 Objects.requireNonNull(zoneOffset, "zoneOffset");
300 if (dayOfMonth > 28) {
301 int dom = numberOfDaysOfMonth(prolepticYear, month);
302 if (dayOfMonth > dom) {
303 if (dayOfMonth == 29) {
304 throw new DateTimeException("Invalid date 'February 29' as '" + prolepticYear + "' is not a leap year");
305 } else {
306 throw new DateTimeException("Invalid date '" + Month.of(month).name() + " " + dayOfMonth + "'");
307 }
308 }
309 }
310
311 long totalDays = 0;
312 int timeinSec = 0;
313 totalDays += 365L * prolepticYear;
314 if (prolepticYear >= 0) {
315 totalDays += (prolepticYear + 3L) / 4 - (prolepticYear + 99L) / 100 + (prolepticYear + 399L) / 400;
316 } else {
317 totalDays -= prolepticYear / -4 - prolepticYear / -100 + prolepticYear / -400;
318 }
319 totalDays += (367 * month - 362) / 12;
320 totalDays += dayOfMonth - 1;
321 if (month > 2) {
322 totalDays--;
323 if (IsoChronology.INSTANCE.isLeapYear(prolepticYear) == false) {
324 totalDays--;
325 }
326 }
327 totalDays -= DAYS_0000_TO_1970;
328 timeinSec = (hour * 60 + minute ) * 60 + second;
329 return Math.addExact(Math.multiplyExact(totalDays, 86400L), timeinSec - zoneOffset.getTotalSeconds());
330 }
331
332 /**
333 * Gets the number of days for the given month in the given year.
334 *
335 * @param year the year to represent, from MIN_YEAR to MAX_YEAR
336 * @param month the month-of-year to represent, from 1 to 12
337 * @return the number of days for the given month in the given year
338 */
339 private int numberOfDaysOfMonth(int year, int month) {
340 int dom;
341 switch (month) {
342 case 2:
343 dom = (IsoChronology.INSTANCE.isLeapYear(year) ? 29 : 28);
344 break;
345 case 4:
346 case 6:
347 case 9:
348 case 11:
349 dom = 30;
350 break;
351 default:
352 dom = 31;
353 break;
354 }
355 return dom;
356 }
357
358
359 /**
360 * Obtains an ISO local date-time from another date-time object.
361 * <p>
362 * This is equivalent to {@link LocalDateTime#from(TemporalAccessor)}.
363 *
364 * @param temporal the date-time object to convert, not null
365 * @return the ISO local date-time, not null
366 * @throws DateTimeException if unable to create the date-time
367 */
368 @Override // override with covariant return type
369 public LocalDateTime localDateTime(TemporalAccessor temporal) {
370 return LocalDateTime.from(temporal);
371 }
372
373 /**
374 * Obtains an ISO zoned date-time from another date-time object.
375 * <p>
376 * This is equivalent to {@link ZonedDateTime#from(TemporalAccessor)}.
377 *
378 * @param temporal the date-time object to convert, not null
379 * @return the ISO zoned date-time, not null
380 * @throws DateTimeException if unable to create the date-time
381 */
382 @Override // override with covariant return type
383 public ZonedDateTime zonedDateTime(TemporalAccessor temporal) {
384 return ZonedDateTime.from(temporal);
385 }
386
387 /**
388 * Obtains an ISO zoned date-time in this chronology from an {@code Instant}.
389 * <p>
390 * This is equivalent to {@link ZonedDateTime#ofInstant(Instant, ZoneId)}.
391 *
392 * @param instant the instant to create the date-time from, not null
393 * @param zone the time-zone, not null
394 * @return the zoned date-time, not null
395 * @throws DateTimeException if the result exceeds the supported range
396 */
397 @Override
398 public ZonedDateTime zonedDateTime(Instant instant, ZoneId zone) {
399 return ZonedDateTime.ofInstant(instant, zone);
400 }
401
402 //-----------------------------------------------------------------------
403 /**
404 * Obtains the current ISO local date from the system clock in the default time-zone.
405 * <p>
406 * This will query the {@link Clock#systemDefaultZone() system clock} in the default
407 * time-zone to obtain the current date.
408 * <p>
409 * Using this method will prevent the ability to use an alternate clock for testing
410 * because the clock is hard-coded.
411 *
412 * @return the current ISO local date using the system clock and default time-zone, not null
413 * @throws DateTimeException if unable to create the date
414 */
415 @Override // override with covariant return type
416 public LocalDate dateNow() {
417 return dateNow(Clock.systemDefaultZone());
418 }
419
420 /**
421 * Obtains the current ISO local date from the system clock in the specified time-zone.
422 * <p>
423 * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
424 * Specifying the time-zone avoids dependence on the default time-zone.
425 * <p>
426 * Using this method will prevent the ability to use an alternate clock for testing
427 * because the clock is hard-coded.
428 *
429 * @return the current ISO local date using the system clock, not null
430 * @throws DateTimeException if unable to create the date
431 */
432 @Override // override with covariant return type
433 public LocalDate dateNow(ZoneId zone) {
434 return dateNow(Clock.system(zone));
435 }
436
437 /**
438 * Obtains the current ISO local date from the specified clock.
439 * <p>
440 * This will query the specified clock to obtain the current date - today.
441 * Using this method allows the use of an alternate clock for testing.
442 * The alternate clock may be introduced using {@link Clock dependency injection}.
443 *
444 * @param clock the clock to use, not null
445 * @return the current ISO local date, not null
446 * @throws DateTimeException if unable to create the date
447 */
448 @Override // override with covariant return type
449 public LocalDate dateNow(Clock clock) {
450 Objects.requireNonNull(clock, "clock");
451 return date(LocalDate.now(clock));
452 }
453
454 //-----------------------------------------------------------------------
455 /**
456 * Checks if the year is a leap year, according to the ISO proleptic
457 * calendar system rules.
458 * <p>
459 * This method applies the current rules for leap years across the whole time-line.
460 * In general, a year is a leap year if it is divisible by four without
461 * remainder. However, years divisible by 100, are not leap years, with
462 * the exception of years divisible by 400 which are.
463 * <p>
464 * For example, 1904 is a leap year it is divisible by 4.
465 * 1900 was not a leap year as it is divisible by 100, however 2000 was a
466 * leap year as it is divisible by 400.
467 * <p>
468 * The calculation is proleptic - applying the same rules into the far future and far past.
469 * This is historically inaccurate, but is correct for the ISO-8601 standard.
470 *
471 * @param prolepticYear the ISO proleptic year to check
472 * @return true if the year is leap, false otherwise
473 */
474 @Override
475 public boolean isLeapYear(long prolepticYear) {
476 return ((prolepticYear & 3) == 0) && ((prolepticYear % 100) != 0 || (prolepticYear % 400) == 0);
477 }
478
479 @Override
480 public int prolepticYear(Era era, int yearOfEra) {
481 if (era instanceof IsoEra == false) {
482 throw new ClassCastException("Era must be IsoEra");
483 }
484 return (era == IsoEra.CE ? yearOfEra : 1 - yearOfEra);
485 }
486
487 @Override
488 public IsoEra eraOf(int eraValue) {
489 return IsoEra.of(eraValue);
490 }
491
492 @Override
493 public List<Era> eras() {
494 return List.of(IsoEra.values());
495 }
496
497 //-----------------------------------------------------------------------
498 /**
499 * Resolves parsed {@code ChronoField} values into a date during parsing.
500 * <p>
501 * Most {@code TemporalField} implementations are resolved using the
502 * resolve method on the field. By contrast, the {@code ChronoField} class
503 * defines fields that only have meaning relative to the chronology.
504 * As such, {@code ChronoField} date fields are resolved here in the
505 * context of a specific chronology.
506 * <p>
507 * {@code ChronoField} instances on the ISO calendar system are resolved
508 * as follows.
509 * <ul>
510 * <li>{@code EPOCH_DAY} - If present, this is converted to a {@code LocalDate}
511 * and all other date fields are then cross-checked against the date.
512 * <li>{@code PROLEPTIC_MONTH} - If present, then it is split into the
513 * {@code YEAR} and {@code MONTH_OF_YEAR}. If the mode is strict or smart
514 * then the field is validated.
515 * <li>{@code YEAR_OF_ERA} and {@code ERA} - If both are present, then they
516 * are combined to form a {@code YEAR}. In lenient mode, the {@code YEAR_OF_ERA}
517 * range is not validated, in smart and strict mode it is. The {@code ERA} is
518 * validated for range in all three modes. If only the {@code YEAR_OF_ERA} is
519 * present, and the mode is smart or lenient, then the current era (CE/AD)
520 * is assumed. In strict mode, no era is assumed and the {@code YEAR_OF_ERA} is
521 * left untouched. If only the {@code ERA} is present, then it is left untouched.
522 * <li>{@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} -
523 * If all three are present, then they are combined to form a {@code LocalDate}.
524 * In all three modes, the {@code YEAR} is validated. If the mode is smart or strict,
525 * then the month and day are validated, with the day validated from 1 to 31.
526 * If the mode is lenient, then the date is combined in a manner equivalent to
527 * creating a date on the first of January in the requested year, then adding
528 * the difference in months, then the difference in days.
529 * If the mode is smart, and the day-of-month is greater than the maximum for
530 * the year-month, then the day-of-month is adjusted to the last day-of-month.
531 * If the mode is strict, then the three fields must form a valid date.
532 * <li>{@code YEAR} and {@code DAY_OF_YEAR} -
533 * If both are present, then they are combined to form a {@code LocalDate}.
534 * In all three modes, the {@code YEAR} is validated.
535 * If the mode is lenient, then the date is combined in a manner equivalent to
536 * creating a date on the first of January in the requested year, then adding
537 * the difference in days.
538 * If the mode is smart or strict, then the two fields must form a valid date.
539 * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and
540 * {@code ALIGNED_DAY_OF_WEEK_IN_MONTH} -
541 * If all four are present, then they are combined to form a {@code LocalDate}.
542 * In all three modes, the {@code YEAR} is validated.
543 * If the mode is lenient, then the date is combined in a manner equivalent to
544 * creating a date on the first of January in the requested year, then adding
545 * the difference in months, then the difference in weeks, then in days.
546 * If the mode is smart or strict, then the all four fields are validated to
547 * their outer ranges. The date is then combined in a manner equivalent to
548 * creating a date on the first day of the requested year and month, then adding
549 * the amount in weeks and days to reach their values. If the mode is strict,
550 * the date is additionally validated to check that the day and week adjustment
551 * did not change the month.
552 * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and
553 * {@code DAY_OF_WEEK} - If all four are present, then they are combined to
554 * form a {@code LocalDate}. The approach is the same as described above for
555 * years, months and weeks in {@code ALIGNED_DAY_OF_WEEK_IN_MONTH}.
556 * The day-of-week is adjusted as the next or same matching day-of-week once
557 * the years, months and weeks have been handled.
558 * <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code ALIGNED_DAY_OF_WEEK_IN_YEAR} -
559 * If all three are present, then they are combined to form a {@code LocalDate}.
560 * In all three modes, the {@code YEAR} is validated.
561 * If the mode is lenient, then the date is combined in a manner equivalent to
562 * creating a date on the first of January in the requested year, then adding
563 * the difference in weeks, then in days.
564 * If the mode is smart or strict, then the all three fields are validated to
565 * their outer ranges. The date is then combined in a manner equivalent to
566 * creating a date on the first day of the requested year, then adding
567 * the amount in weeks and days to reach their values. If the mode is strict,
568 * the date is additionally validated to check that the day and week adjustment
569 * did not change the year.
570 * <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code DAY_OF_WEEK} -
571 * If all three are present, then they are combined to form a {@code LocalDate}.
572 * The approach is the same as described above for years and weeks in
573 * {@code ALIGNED_DAY_OF_WEEK_IN_YEAR}. The day-of-week is adjusted as the
574 * next or same matching day-of-week once the years and weeks have been handled.
575 * </ul>
576 *
577 * @param fieldValues the map of fields to values, which can be updated, not null
578 * @param resolverStyle the requested type of resolve, not null
579 * @return the resolved date, null if insufficient information to create a date
580 * @throws DateTimeException if the date cannot be resolved, typically
581 * because of a conflict in the input data
582 */
583 @Override // override for performance
584 public LocalDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
585 return (LocalDate) super.resolveDate(fieldValues, resolverStyle);
586 }
587
588 @Override // override for better proleptic algorithm
589 void resolveProlepticMonth(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
590 Long pMonth = fieldValues.remove(PROLEPTIC_MONTH);
591 if (pMonth != null) {
592 if (resolverStyle != ResolverStyle.LENIENT) {
593 PROLEPTIC_MONTH.checkValidValue(pMonth);
594 }
595 addFieldValue(fieldValues, MONTH_OF_YEAR, Math.floorMod(pMonth, 12) + 1);
596 addFieldValue(fieldValues, YEAR, Math.floorDiv(pMonth, 12));
597 }
598 }
599
600 @Override // override for enhanced behaviour
601 LocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
602 Long yoeLong = fieldValues.remove(YEAR_OF_ERA);
603 if (yoeLong != null) {
604 if (resolverStyle != ResolverStyle.LENIENT) {
605 YEAR_OF_ERA.checkValidValue(yoeLong);
606 }
607 Long era = fieldValues.remove(ERA);
608 if (era == null) {
609 Long year = fieldValues.get(YEAR);
610 if (resolverStyle == ResolverStyle.STRICT) {
611 // do not invent era if strict, but do cross-check with year
612 if (year != null) {
613 addFieldValue(fieldValues, YEAR, (year > 0 ? yoeLong: Math.subtractExact(1, yoeLong)));
614 } else {
615 // reinstate the field removed earlier, no cross-check issues
616 fieldValues.put(YEAR_OF_ERA, yoeLong);
617 }
618 } else {
619 // invent era
620 addFieldValue(fieldValues, YEAR, (year == null || year > 0 ? yoeLong: Math.subtractExact(1, yoeLong)));
621 }
622 } else if (era.longValue() == 1L) {
623 addFieldValue(fieldValues, YEAR, yoeLong);
624 } else if (era.longValue() == 0L) {
625 addFieldValue(fieldValues, YEAR, Math.subtractExact(1, yoeLong));
626 } else {
627 throw new DateTimeException("Invalid value for era: " + era);
628 }
629 } else if (fieldValues.containsKey(ERA)) {
630 ERA.checkValidValue(fieldValues.get(ERA)); // always validated
631 }
632 return null;
633 }
634
635 @Override // override for performance
636 LocalDate resolveYMD(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
637 int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
638 if (resolverStyle == ResolverStyle.LENIENT) {
639 long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
640 long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
641 return LocalDate.of(y, 1, 1).plusMonths(months).plusDays(days);
642 }
643 int moy = MONTH_OF_YEAR.checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR));
644 int dom = DAY_OF_MONTH.checkValidIntValue(fieldValues.remove(DAY_OF_MONTH));
645 if (resolverStyle == ResolverStyle.SMART) { // previous valid
646 if (moy == 4 || moy == 6 || moy == 9 || moy == 11) {
647 dom = Math.min(dom, 30);
648 } else if (moy == 2) {
649 dom = Math.min(dom, Month.FEBRUARY.length(Year.isLeap(y)));
650
651 }
652 }
653 return LocalDate.of(y, moy, dom);
654 }
655
656 //-----------------------------------------------------------------------
657 @Override
658 public ValueRange range(ChronoField field) {
659 return field.range();
660 }
661
662 //-----------------------------------------------------------------------
663 /**
664 * Obtains a period for this chronology based on years, months and days.
665 * <p>
666 * This returns a period tied to the ISO chronology using the specified
667 * years, months and days. See {@link Period} for further details.
668 *
669 * @param years the number of years, may be negative
670 * @param months the number of years, may be negative
671 * @param days the number of years, may be negative
672 * @return the ISO period, not null
673 */
674 @Override // override with covariant return type
675 public Period period(int years, int months, int days) {
676 return Period.of(years, months, days);
677 }
678
679 //-----------------------------------------------------------------------
680 /**
681 * Writes the Chronology using a
682 * <a href="{@docRoot}/serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
683 * @serialData
684 * <pre>
685 * out.writeByte(1); // identifies a Chronology
686 * out.writeUTF(getId());
687 * </pre>
688 *
689 * @return the instance of {@code Ser}, not null
690 */
691 @Override
692 Object writeReplace() {
693 return super.writeReplace();
694 }
695
696 /**
697 * Defend against malicious streams.
698 *
699 * @param s the stream to read
700 * @throws InvalidObjectException always
701 */
702 private void readObject(ObjectInputStream s) throws InvalidObjectException {
703 throw new InvalidObjectException("Deserialization via serialization delegate");
704 }
705 }