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 * 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.Arrays;
94 import java.util.List;
95 import java.util.Locale;
96 import java.util.Map;
97 import java.util.Objects;
98
99 /**
100 * The ISO calendar system.
101 * <p>
102 * This chronology defines the rules of the ISO calendar system.
103 * This calendar system is based on the ISO-8601 standard, which is the
104 * <i>de facto</i> world calendar.
105 * <p>
106 * The fields are defined as follows:
107 * <ul>
108 * <li>era - There are two eras, 'Current Era' (CE) and 'Before Current Era' (BCE).
109 * <li>year-of-era - The year-of-era is the same as the proleptic-year for the current CE era.
110 * For the BCE era before the ISO epoch the year increases from 1 upwards as time goes backwards.
111 * <li>proleptic-year - The proleptic year is the same as the year-of-era for the
112 * current era. For the previous era, years have zero, then negative values.
113 * <li>month-of-year - There are 12 months in an ISO year, numbered from 1 to 12.
114 * <li>day-of-month - There are between 28 and 31 days in each of the ISO month, numbered from 1 to 31.
115 * Months 4, 6, 9 and 11 have 30 days, Months 1, 3, 5, 7, 8, 10 and 12 have 31 days.
116 * Month 2 has 28 days, or 29 in a leap year.
117 * <li>day-of-year - There are 365 days in a standard ISO year and 366 in a leap year.
118 * The days are numbered from 1 to 365 or 1 to 366.
119 * <li>leap-year - Leap years occur every 4 years, except where the year is divisble by 100 and not divisble by 400.
120 * </ul>
121 *
122 * @implSpec
123 * This class is immutable and thread-safe.
124 *
125 * @since 1.8
126 */
127 public final class IsoChronology extends AbstractChronology implements Serializable {
128
129 /**
130 * Singleton instance of the ISO chronology.
131 */
132 public static final IsoChronology INSTANCE = new IsoChronology();
133
134 /**
135 * Serialization version.
136 */
137 private static final long serialVersionUID = -1440403870442975015L;
138
139 private static final long DAYS_0000_TO_1970 = (146097 * 5L) - (30L * 365L + 7L); // taken from LocalDate
140
141 /**
142 * Restricted constructor.
143 */
144 private IsoChronology() {
145 }
146
147 //-----------------------------------------------------------------------
148 /**
149 * Gets the ID of the chronology - 'ISO'.
150 * <p>
151 * The ID uniquely identifies the {@code Chronology}.
152 * It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
153 *
154 * @return the chronology ID - 'ISO'
155 * @see #getCalendarType()
156 */
157 @Override
158 public String getId() {
159 return "ISO";
160 }
161
162 /**
163 * Gets the calendar type of the underlying calendar system - 'iso8601'.
164 * <p>
165 * The calendar type is an identifier defined by the
166 * <em>Unicode Locale Data Markup Language (LDML)</em> specification.
167 * It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
168 * It can also be used as part of a locale, accessible via
169 * {@link Locale#getUnicodeLocaleType(String)} with the key 'ca'.
170 *
171 * @return the calendar system type - 'iso8601'
172 * @see #getId()
173 */
174 @Override
175 public String getCalendarType() {
176 return "iso8601";
177 }
178
179 //-----------------------------------------------------------------------
180 /**
181 * Obtains an ISO local date from the era, year-of-era, month-of-year
182 * and day-of-month fields.
183 *
184 * @param era the ISO era, not null
185 * @param yearOfEra the ISO year-of-era
186 * @param month the ISO month-of-year
187 * @param dayOfMonth the ISO day-of-month
188 * @return the ISO local date, not null
189 * @throws DateTimeException if unable to create the date
190 * @throws ClassCastException if the type of {@code era} is not {@code IsoEra}
191 */
192 @Override // override with covariant return type
193 public LocalDate date(Era era, int yearOfEra, int month, int dayOfMonth) {
194 return date(prolepticYear(era, yearOfEra), month, dayOfMonth);
195 }
196
197 /**
198 * Obtains an ISO local date from the proleptic-year, month-of-year
199 * and day-of-month fields.
200 * <p>
201 * This is equivalent to {@link LocalDate#of(int, int, int)}.
202 *
203 * @param prolepticYear the ISO proleptic-year
204 * @param month the ISO month-of-year
205 * @param dayOfMonth the ISO day-of-month
206 * @return the ISO local date, not null
207 * @throws DateTimeException if unable to create the date
208 */
209 @Override // override with covariant return type
210 public LocalDate date(int prolepticYear, int month, int dayOfMonth) {
211 return LocalDate.of(prolepticYear, month, dayOfMonth);
212 }
213
214 /**
215 * Obtains an ISO local date from the era, year-of-era and day-of-year fields.
216 *
217 * @param era the ISO era, not null
218 * @param yearOfEra the ISO year-of-era
219 * @param dayOfYear the ISO day-of-year
220 * @return the ISO local date, not null
221 * @throws DateTimeException if unable to create the date
222 */
223 @Override // override with covariant return type
224 public LocalDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {
225 return dateYearDay(prolepticYear(era, yearOfEra), dayOfYear);
226 }
227
228 /**
229 * Obtains an ISO local date from the proleptic-year and day-of-year fields.
230 * <p>
231 * This is equivalent to {@link LocalDate#ofYearDay(int, int)}.
232 *
233 * @param prolepticYear the ISO proleptic-year
234 * @param dayOfYear the ISO day-of-year
235 * @return the ISO local date, not null
236 * @throws DateTimeException if unable to create the date
237 */
238 @Override // override with covariant return type
239 public LocalDate dateYearDay(int prolepticYear, int dayOfYear) {
240 return LocalDate.ofYearDay(prolepticYear, dayOfYear);
241 }
242
243 /**
244 * Obtains an ISO local date from the epoch-day.
245 * <p>
246 * This is equivalent to {@link LocalDate#ofEpochDay(long)}.
247 *
248 * @param epochDay the epoch day
249 * @return the ISO local date, not null
250 * @throws DateTimeException if unable to create the date
251 */
252 @Override // override with covariant return type
253 public LocalDate dateEpochDay(long epochDay) {
254 return LocalDate.ofEpochDay(epochDay);
255 }
256
257 //-----------------------------------------------------------------------
258 /**
259 * Obtains an ISO local date from another date-time object.
260 * <p>
261 * This is equivalent to {@link LocalDate#from(TemporalAccessor)}.
262 *
263 * @param temporal the date-time object to convert, not null
264 * @return the ISO local date, not null
265 * @throws DateTimeException if unable to create the date
266 */
267 @Override // override with covariant return type
268 public LocalDate date(TemporalAccessor temporal) {
269 return LocalDate.from(temporal);
270 }
271
272 //-----------------------------------------------------------------------
273 /**
274 * Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z.
275 * <p>
276 * The number of seconds is calculated using the year,
277 * month, day-of-month, hour, minute, second, and zoneOffset.
278 *
279 * @param prolepticYear the year, from MIN_YEAR to MAX_YEAR
280 * @param month the month-of-year, from 1 to 12
281 * @param dayOfMonth the day-of-month, from 1 to 31
282 * @param hour the hour-of-day, from 0 to 23
283 * @param minute the minute-of-hour, from 0 to 59
284 * @param second the second-of-minute, from 0 to 59
285 * @param zoneOffset the zone offset, not null
286 * @return the number of seconds relative to 1970-01-01T00:00:00Z, may be negative
287 * @throws DateTimeException if the value of any field is out of range,
288 * or if the day-of-month is invalid for the month-of-year
289 * @since 9
290 */
291 @Override
292 public long epochSecond(int prolepticYear, int month, int dayOfMonth,
293 int hour, int minute, int second, ZoneOffset zoneOffset) {
294 YEAR.checkValidValue(prolepticYear);
295 MONTH_OF_YEAR.checkValidValue(month);
296 DAY_OF_MONTH.checkValidValue(dayOfMonth);
297 HOUR_OF_DAY.checkValidValue(hour);
298 MINUTE_OF_HOUR.checkValidValue(minute);
299 SECOND_OF_MINUTE.checkValidValue(second);
300 Objects.requireNonNull(zoneOffset, "zoneOffset");
301 if (dayOfMonth > 28) {
302 int dom = numberOfDaysOfMonth(prolepticYear, month);
303 if (dayOfMonth > dom) {
304 if (dayOfMonth == 29) {
305 throw new DateTimeException("Invalid date 'February 29' as '" + prolepticYear + "' is not a leap year");
306 } else {
307 throw new DateTimeException("Invalid date '" + Month.of(month).name() + " " + dayOfMonth + "'");
308 }
309 }
310 }
311
312 long totalDays = 0;
313 int timeinSec = 0;
314 totalDays += 365L * prolepticYear;
315 if (prolepticYear >= 0) {
316 totalDays += (prolepticYear + 3L) / 4 - (prolepticYear + 99L) / 100 + (prolepticYear + 399L) / 400;
317 } else {
318 totalDays -= prolepticYear / -4 - prolepticYear / -100 + prolepticYear / -400;
319 }
320 totalDays += (367 * month - 362) / 12;
321 totalDays += dayOfMonth - 1;
322 if (month > 2) {
323 totalDays--;
324 if (IsoChronology.INSTANCE.isLeapYear(prolepticYear) == false) {
325 totalDays--;
326 }
327 }
328 totalDays -= DAYS_0000_TO_1970;
329 timeinSec = (hour * 60 + minute ) * 60 + second;
330 return Math.addExact(Math.multiplyExact(totalDays, 86400L), timeinSec - zoneOffset.getTotalSeconds());
331 }
332
333 /**
334 * Gets the number of days for the given month in the given year.
335 *
336 * @param year the year to represent, from MIN_YEAR to MAX_YEAR
337 * @param month the month-of-year to represent, from 1 to 12
338 * @return the number of days for the given month in the given year
339 */
340 private int numberOfDaysOfMonth(int year, int month) {
341 int dom;
342 switch (month) {
343 case 2:
344 dom = (IsoChronology.INSTANCE.isLeapYear(year) ? 29 : 28);
345 break;
346 case 4:
347 case 6:
348 case 9:
349 case 11:
350 dom = 30;
351 break;
352 default:
353 dom = 31;
354 break;
355 }
356 return dom;
357 }
358
359
360 /**
361 * Obtains an ISO local date-time from another date-time object.
362 * <p>
363 * This is equivalent to {@link LocalDateTime#from(TemporalAccessor)}.
364 *
365 * @param temporal the date-time object to convert, not null
366 * @return the ISO local date-time, not null
367 * @throws DateTimeException if unable to create the date-time
368 */
369 @Override // override with covariant return type
370 public LocalDateTime localDateTime(TemporalAccessor temporal) {
371 return LocalDateTime.from(temporal);
372 }
373
374 /**
375 * Obtains an ISO zoned date-time from another date-time object.
376 * <p>
377 * This is equivalent to {@link ZonedDateTime#from(TemporalAccessor)}.
378 *
379 * @param temporal the date-time object to convert, not null
380 * @return the ISO zoned date-time, not null
381 * @throws DateTimeException if unable to create the date-time
382 */
383 @Override // override with covariant return type
384 public ZonedDateTime zonedDateTime(TemporalAccessor temporal) {
385 return ZonedDateTime.from(temporal);
386 }
387
388 /**
389 * Obtains an ISO zoned date-time in this chronology from an {@code Instant}.
390 * <p>
391 * This is equivalent to {@link ZonedDateTime#ofInstant(Instant, ZoneId)}.
392 *
393 * @param instant the instant to create the date-time from, not null
394 * @param zone the time-zone, not null
395 * @return the zoned date-time, not null
396 * @throws DateTimeException if the result exceeds the supported range
397 */
398 @Override
399 public ZonedDateTime zonedDateTime(Instant instant, ZoneId zone) {
400 return ZonedDateTime.ofInstant(instant, zone);
401 }
402
403 //-----------------------------------------------------------------------
404 /**
405 * Obtains the current ISO local date from the system clock in the default time-zone.
406 * <p>
407 * This will query the {@link Clock#systemDefaultZone() system clock} in the default
408 * time-zone to obtain the current date.
409 * <p>
410 * Using this method will prevent the ability to use an alternate clock for testing
411 * because the clock is hard-coded.
412 *
413 * @return the current ISO local date using the system clock and default time-zone, not null
414 * @throws DateTimeException if unable to create the date
415 */
416 @Override // override with covariant return type
417 public LocalDate dateNow() {
418 return dateNow(Clock.systemDefaultZone());
419 }
420
421 /**
422 * Obtains the current ISO local date from the system clock in the specified time-zone.
423 * <p>
424 * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
425 * Specifying the time-zone avoids dependence on the default time-zone.
426 * <p>
427 * Using this method will prevent the ability to use an alternate clock for testing
428 * because the clock is hard-coded.
429 *
430 * @return the current ISO local date using the system clock, not null
431 * @throws DateTimeException if unable to create the date
432 */
433 @Override // override with covariant return type
434 public LocalDate dateNow(ZoneId zone) {
435 return dateNow(Clock.system(zone));
436 }
437
438 /**
439 * Obtains the current ISO local date from the specified clock.
440 * <p>
441 * This will query the specified clock to obtain the current date - today.
442 * Using this method allows the use of an alternate clock for testing.
443 * The alternate clock may be introduced using {@link Clock dependency injection}.
444 *
445 * @param clock the clock to use, not null
446 * @return the current ISO local date, not null
447 * @throws DateTimeException if unable to create the date
448 */
449 @Override // override with covariant return type
450 public LocalDate dateNow(Clock clock) {
451 Objects.requireNonNull(clock, "clock");
452 return date(LocalDate.now(clock));
453 }
454
455 //-----------------------------------------------------------------------
456 /**
457 * Checks if the year is a leap year, according to the ISO proleptic
458 * calendar system rules.
459 * <p>
460 * This method applies the current rules for leap years across the whole time-line.
461 * In general, a year is a leap year if it is divisible by four without
462 * remainder. However, years divisible by 100, are not leap years, with
463 * the exception of years divisible by 400 which are.
464 * <p>
465 * For example, 1904 is a leap year it is divisible by 4.
466 * 1900 was not a leap year as it is divisible by 100, however 2000 was a
467 * leap year as it is divisible by 400.
468 * <p>
469 * The calculation is proleptic - applying the same rules into the far future and far past.
470 * This is historically inaccurate, but is correct for the ISO-8601 standard.
471 *
472 * @param prolepticYear the ISO proleptic year to check
473 * @return true if the year is leap, false otherwise
474 */
475 @Override
476 public boolean isLeapYear(long prolepticYear) {
477 return ((prolepticYear & 3) == 0) && ((prolepticYear % 100) != 0 || (prolepticYear % 400) == 0);
478 }
479
480 @Override
481 public int prolepticYear(Era era, int yearOfEra) {
482 if (era instanceof IsoEra == false) {
483 throw new ClassCastException("Era must be IsoEra");
484 }
485 return (era == IsoEra.CE ? yearOfEra : 1 - yearOfEra);
486 }
487
488 @Override
489 public IsoEra eraOf(int eraValue) {
490 return IsoEra.of(eraValue);
491 }
492
493 @Override
494 public List<Era> eras() {
495 return Arrays.<Era>asList(IsoEra.values());
496 }
497
498 //-----------------------------------------------------------------------
499 /**
500 * Resolves parsed {@code ChronoField} values into a date during parsing.
501 * <p>
502 * Most {@code TemporalField} implementations are resolved using the
503 * resolve method on the field. By contrast, the {@code ChronoField} class
504 * defines fields that only have meaning relative to the chronology.
505 * As such, {@code ChronoField} date fields are resolved here in the
506 * context of a specific chronology.
507 * <p>
508 * {@code ChronoField} instances on the ISO calendar system are resolved
509 * as follows.
510 * <ul>
511 * <li>{@code EPOCH_DAY} - If present, this is converted to a {@code LocalDate}
512 * and all other date fields are then cross-checked against the date.
513 * <li>{@code PROLEPTIC_MONTH} - If present, then it is split into the
514 * {@code YEAR} and {@code MONTH_OF_YEAR}. If the mode is strict or smart
515 * then the field is validated.
516 * <li>{@code YEAR_OF_ERA} and {@code ERA} - If both are present, then they
517 * are combined to form a {@code YEAR}. In lenient mode, the {@code YEAR_OF_ERA}
518 * range is not validated, in smart and strict mode it is. The {@code ERA} is
519 * validated for range in all three modes. If only the {@code YEAR_OF_ERA} is
520 * present, and the mode is smart or lenient, then the current era (CE/AD)
521 * is assumed. In strict mode, no era is assumed and the {@code YEAR_OF_ERA} is
522 * left untouched. If only the {@code ERA} is present, then it is left untouched.
523 * <li>{@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} -
524 * If all three are present, then they are combined to form a {@code LocalDate}.
525 * In all three modes, the {@code YEAR} is validated. If the mode is smart or strict,
526 * then the month and day are validated, with the day validated from 1 to 31.
527 * If the mode is lenient, then the date is combined in a manner equivalent to
528 * creating a date on the first of January in the requested year, then adding
529 * the difference in months, then the difference in days.
530 * If the mode is smart, and the day-of-month is greater than the maximum for
531 * the year-month, then the day-of-month is adjusted to the last day-of-month.
532 * If the mode is strict, then the three fields must form a valid date.
533 * <li>{@code YEAR} and {@code DAY_OF_YEAR} -
534 * If both are present, then they are combined to form a {@code LocalDate}.
535 * In all three modes, the {@code YEAR} is validated.
536 * If the mode is lenient, then the date is combined in a manner equivalent to
537 * creating a date on the first of January in the requested year, then adding
538 * the difference in days.
539 * If the mode is smart or strict, then the two fields must form a valid date.
540 * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and
541 * {@code ALIGNED_DAY_OF_WEEK_IN_MONTH} -
542 * If all four are present, then they are combined to form a {@code LocalDate}.
543 * In all three modes, the {@code YEAR} is validated.
544 * If the mode is lenient, then the date is combined in a manner equivalent to
545 * creating a date on the first of January in the requested year, then adding
546 * the difference in months, then the difference in weeks, then in days.
547 * If the mode is smart or strict, then the all four fields are validated to
548 * their outer ranges. The date is then combined in a manner equivalent to
549 * creating a date on the first day of the requested year and month, then adding
550 * the amount in weeks and days to reach their values. If the mode is strict,
551 * the date is additionally validated to check that the day and week adjustment
552 * did not change the month.
553 * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and
554 * {@code DAY_OF_WEEK} - If all four are present, then they are combined to
555 * form a {@code LocalDate}. The approach is the same as described above for
556 * years, months and weeks in {@code ALIGNED_DAY_OF_WEEK_IN_MONTH}.
557 * The day-of-week is adjusted as the next or same matching day-of-week once
558 * the years, months and weeks have been handled.
559 * <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code ALIGNED_DAY_OF_WEEK_IN_YEAR} -
560 * If all three are present, then they are combined to form a {@code LocalDate}.
561 * In all three modes, the {@code YEAR} is validated.
562 * If the mode is lenient, then the date is combined in a manner equivalent to
563 * creating a date on the first of January in the requested year, then adding
564 * the difference in weeks, then in days.
565 * If the mode is smart or strict, then the all three fields are validated to
566 * their outer ranges. The date is then combined in a manner equivalent to
567 * creating a date on the first day of the requested year, then adding
568 * the amount in weeks and days to reach their values. If the mode is strict,
569 * the date is additionally validated to check that the day and week adjustment
570 * did not change the year.
571 * <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code DAY_OF_WEEK} -
572 * If all three are present, then they are combined to form a {@code LocalDate}.
573 * The approach is the same as described above for years and weeks in
574 * {@code ALIGNED_DAY_OF_WEEK_IN_YEAR}. The day-of-week is adjusted as the
575 * next or same matching day-of-week once the years and weeks have been handled.
576 * </ul>
577 *
578 * @param fieldValues the map of fields to values, which can be updated, not null
579 * @param resolverStyle the requested type of resolve, not null
580 * @return the resolved date, null if insufficient information to create a date
581 * @throws DateTimeException if the date cannot be resolved, typically
582 * because of a conflict in the input data
583 */
584 @Override // override for performance
585 public LocalDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
586 return (LocalDate) super.resolveDate(fieldValues, resolverStyle);
587 }
588
589 @Override // override for better proleptic algorithm
590 void resolveProlepticMonth(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
591 Long pMonth = fieldValues.remove(PROLEPTIC_MONTH);
592 if (pMonth != null) {
593 if (resolverStyle != ResolverStyle.LENIENT) {
594 PROLEPTIC_MONTH.checkValidValue(pMonth);
595 }
596 addFieldValue(fieldValues, MONTH_OF_YEAR, Math.floorMod(pMonth, 12) + 1);
597 addFieldValue(fieldValues, YEAR, Math.floorDiv(pMonth, 12));
598 }
599 }
600
601 @Override // override for enhanced behaviour
602 LocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
603 Long yoeLong = fieldValues.remove(YEAR_OF_ERA);
604 if (yoeLong != null) {
605 if (resolverStyle != ResolverStyle.LENIENT) {
606 YEAR_OF_ERA.checkValidValue(yoeLong);
607 }
608 Long era = fieldValues.remove(ERA);
609 if (era == null) {
610 Long year = fieldValues.get(YEAR);
611 if (resolverStyle == ResolverStyle.STRICT) {
612 // do not invent era if strict, but do cross-check with year
613 if (year != null) {
614 addFieldValue(fieldValues, YEAR, (year > 0 ? yoeLong: Math.subtractExact(1, yoeLong)));
615 } else {
616 // reinstate the field removed earlier, no cross-check issues
617 fieldValues.put(YEAR_OF_ERA, yoeLong);
618 }
619 } else {
620 // invent era
621 addFieldValue(fieldValues, YEAR, (year == null || year > 0 ? yoeLong: Math.subtractExact(1, yoeLong)));
622 }
623 } else if (era.longValue() == 1L) {
624 addFieldValue(fieldValues, YEAR, yoeLong);
625 } else if (era.longValue() == 0L) {
626 addFieldValue(fieldValues, YEAR, Math.subtractExact(1, yoeLong));
627 } else {
628 throw new DateTimeException("Invalid value for era: " + era);
629 }
630 } else if (fieldValues.containsKey(ERA)) {
631 ERA.checkValidValue(fieldValues.get(ERA)); // always validated
632 }
633 return null;
634 }
635
636 @Override // override for performance
637 LocalDate resolveYMD(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
638 int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
639 if (resolverStyle == ResolverStyle.LENIENT) {
640 long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
641 long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
642 return LocalDate.of(y, 1, 1).plusMonths(months).plusDays(days);
643 }
644 int moy = MONTH_OF_YEAR.checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR));
645 int dom = DAY_OF_MONTH.checkValidIntValue(fieldValues.remove(DAY_OF_MONTH));
646 if (resolverStyle == ResolverStyle.SMART) { // previous valid
647 if (moy == 4 || moy == 6 || moy == 9 || moy == 11) {
648 dom = Math.min(dom, 30);
649 } else if (moy == 2) {
650 dom = Math.min(dom, Month.FEBRUARY.length(Year.isLeap(y)));
651
652 }
653 }
654 return LocalDate.of(y, moy, dom);
655 }
656
657 //-----------------------------------------------------------------------
658 @Override
659 public ValueRange range(ChronoField field) {
660 return field.range();
661 }
662
663 //-----------------------------------------------------------------------
664 /**
665 * Obtains a period for this chronology based on years, months and days.
666 * <p>
667 * This returns a period tied to the ISO chronology using the specified
668 * years, months and days. See {@link Period} for further details.
669 *
670 * @param years the number of years, may be negative
671 * @param months the number of years, may be negative
672 * @param days the number of years, may be negative
673 * @return the period in terms of this chronology, not null
674 * @return the ISO period, not null
675 */
676 @Override // override with covariant return type
677 public Period period(int years, int months, int days) {
678 return Period.of(years, months, days);
679 }
680
681 //-----------------------------------------------------------------------
682 /**
683 * Writes the Chronology using a
684 * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
685 * @serialData
686 * <pre>
687 * out.writeByte(1); // identifies a Chronology
688 * out.writeUTF(getId());
689 * </pre>
690 *
691 * @return the instance of {@code Ser}, not null
692 */
693 @Override
694 Object writeReplace() {
695 return super.writeReplace();
696 }
697
698 /**
699 * Defend against malicious streams.
700 *
701 * @param s the stream to read
702 * @throws InvalidObjectException always
703 */
704 private void readObject(ObjectInputStream s) throws InvalidObjectException {
705 throw new InvalidObjectException("Deserialization via serialization delegate");
706 }
707 }