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 @java.io.Serial 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 argument 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 List.of(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 ISO period, not null 674 */ 675 @Override // override with covariant return type 676 public Period period(int years, int months, int days) { 677 return Period.of(years, months, days); 678 } 679 680 //----------------------------------------------------------------------- 681 /** 682 * Writes the Chronology using a 683 * <a href="{@docRoot}/serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>. 684 * @serialData 685 * <pre> 686 * out.writeByte(1); // identifies a Chronology 687 * out.writeUTF(getId()); 688 * </pre> 689 * 690 * @return the instance of {@code Ser}, not null 691 */ 692 @Override 693 @java.io.Serial 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 @java.io.Serial 705 private void readObject(ObjectInputStream s) throws InvalidObjectException { 706 throw new InvalidObjectException("Deserialization via serialization delegate"); 707 } 708 }