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) 2008-2012, 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; 63 64 import static java.time.temporal.ChronoUnit.DAYS; 65 import static java.time.temporal.ChronoUnit.MONTHS; 66 import static java.time.temporal.ChronoUnit.YEARS; 67 68 import java.io.DataInput; 69 import java.io.DataOutput; 70 import java.io.IOException; 71 import java.io.InvalidObjectException; 72 import java.io.ObjectInputStream; 73 import java.io.Serializable; 74 import java.time.chrono.ChronoLocalDate; 75 import java.time.chrono.ChronoPeriod; 76 import java.time.chrono.Chronology; 77 import java.time.chrono.IsoChronology; 78 import java.time.format.DateTimeParseException; 79 import java.time.temporal.ChronoUnit; 80 import java.time.temporal.Temporal; 81 import java.time.temporal.TemporalAccessor; 82 import java.time.temporal.TemporalAmount; 83 import java.time.temporal.TemporalQueries; 84 import java.time.temporal.TemporalUnit; 85 import java.time.temporal.UnsupportedTemporalTypeException; 86 import java.util.List; 87 import java.util.Objects; 88 import java.util.regex.Matcher; 89 import java.util.regex.Pattern; 90 91 // Android-changed: removed ValueBased paragraph. 92 /** 93 * A date-based amount of time in the ISO-8601 calendar system, 94 * such as '2 years, 3 months and 4 days'. 95 * <p> 96 * This class models a quantity or amount of time in terms of years, months and days. 97 * See {@link Duration} for the time-based equivalent to this class. 98 * <p> 99 * Durations and periods differ in their treatment of daylight savings time 100 * when added to {@link ZonedDateTime}. A {@code Duration} will add an exact 101 * number of seconds, thus a duration of one day is always exactly 24 hours. 102 * By contrast, a {@code Period} will add a conceptual day, trying to maintain 103 * the local time. 104 * <p> 105 * For example, consider adding a period of one day and a duration of one day to 106 * 18:00 on the evening before a daylight savings gap. The {@code Period} will add 107 * the conceptual day and result in a {@code ZonedDateTime} at 18:00 the following day. 108 * By contrast, the {@code Duration} will add exactly 24 hours, resulting in a 109 * {@code ZonedDateTime} at 19:00 the following day (assuming a one hour DST gap). 110 * <p> 111 * The supported units of a period are {@link ChronoUnit#YEARS YEARS}, 112 * {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. 113 * All three fields are always present, but may be set to zero. 114 * <p> 115 * The ISO-8601 calendar system is the modern civil calendar system used today 116 * in most of the world. It is equivalent to the proleptic Gregorian calendar 117 * system, in which today's rules for leap years are applied for all time. 118 * <p> 119 * The period is modeled as a directed amount of time, meaning that individual parts of the 120 * period may be negative. 121 * 122 * @implSpec 123 * This class is immutable and thread-safe. 124 * 125 * @since 1.8 126 */ 127 public final class Period 128 implements ChronoPeriod, Serializable { 129 130 /** 131 * A constant for a period of zero. 132 */ 133 public static final Period ZERO = new Period(0, 0, 0); 134 /** 135 * Serialization version. 136 */ 137 private static final long serialVersionUID = -3587258372562876L; 138 /** 139 * The pattern for parsing. 140 */ 141 private static final Pattern PATTERN = 142 Pattern.compile("([-+]?)P(?:([-+]?[0-9]+)Y)?(?:([-+]?[0-9]+)M)?(?:([-+]?[0-9]+)W)?(?:([-+]?[0-9]+)D)?", Pattern.CASE_INSENSITIVE); 143 144 /** 145 * The set of supported units. 146 */ 147 private static final List<TemporalUnit> SUPPORTED_UNITS = List.of(YEARS, MONTHS, DAYS); 148 149 /** 150 * The number of years. 151 */ 152 private final int years; 153 /** 154 * The number of months. 155 */ 156 private final int months; 157 /** 158 * The number of days. 159 */ 160 private final int days; 161 162 //----------------------------------------------------------------------- 163 /** 164 * Obtains a {@code Period} representing a number of years. 165 * <p> 166 * The resulting period will have the specified years. 167 * The months and days units will be zero. 168 * 169 * @param years the number of years, positive or negative 170 * @return the period of years, not null 171 */ ofYears(int years)172 public static Period ofYears(int years) { 173 return create(years, 0, 0); 174 } 175 176 /** 177 * Obtains a {@code Period} representing a number of months. 178 * <p> 179 * The resulting period will have the specified months. 180 * The years and days units will be zero. 181 * 182 * @param months the number of months, positive or negative 183 * @return the period of months, not null 184 */ ofMonths(int months)185 public static Period ofMonths(int months) { 186 return create(0, months, 0); 187 } 188 189 /** 190 * Obtains a {@code Period} representing a number of weeks. 191 * <p> 192 * The resulting period will be day-based, with the amount of days 193 * equal to the number of weeks multiplied by 7. 194 * The years and months units will be zero. 195 * 196 * @param weeks the number of weeks, positive or negative 197 * @return the period, with the input weeks converted to days, not null 198 */ ofWeeks(int weeks)199 public static Period ofWeeks(int weeks) { 200 return create(0, 0, Math.multiplyExact(weeks, 7)); 201 } 202 203 /** 204 * Obtains a {@code Period} representing a number of days. 205 * <p> 206 * The resulting period will have the specified days. 207 * The years and months units will be zero. 208 * 209 * @param days the number of days, positive or negative 210 * @return the period of days, not null 211 */ ofDays(int days)212 public static Period ofDays(int days) { 213 return create(0, 0, days); 214 } 215 216 //----------------------------------------------------------------------- 217 /** 218 * Obtains a {@code Period} representing a number of years, months and days. 219 * <p> 220 * This creates an instance based on years, months and days. 221 * 222 * @param years the amount of years, may be negative 223 * @param months the amount of months, may be negative 224 * @param days the amount of days, may be negative 225 * @return the period of years, months and days, not null 226 */ of(int years, int months, int days)227 public static Period of(int years, int months, int days) { 228 return create(years, months, days); 229 } 230 231 //----------------------------------------------------------------------- 232 /** 233 * Obtains an instance of {@code Period} from a temporal amount. 234 * <p> 235 * This obtains a period based on the specified amount. 236 * A {@code TemporalAmount} represents an amount of time, which may be 237 * date-based or time-based, which this factory extracts to a {@code Period}. 238 * <p> 239 * The conversion loops around the set of units from the amount and uses 240 * the {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} 241 * and {@link ChronoUnit#DAYS DAYS} units to create a period. 242 * If any other units are found then an exception is thrown. 243 * <p> 244 * If the amount is a {@code ChronoPeriod} then it must use the ISO chronology. 245 * 246 * @param amount the temporal amount to convert, not null 247 * @return the equivalent period, not null 248 * @throws DateTimeException if unable to convert to a {@code Period} 249 * @throws ArithmeticException if the amount of years, months or days exceeds an int 250 */ from(TemporalAmount amount)251 public static Period from(TemporalAmount amount) { 252 if (amount instanceof Period) { 253 return (Period) amount; 254 } 255 if (amount instanceof ChronoPeriod) { 256 if (IsoChronology.INSTANCE.equals(((ChronoPeriod) amount).getChronology()) == false) { 257 throw new DateTimeException("Period requires ISO chronology: " + amount); 258 } 259 } 260 Objects.requireNonNull(amount, "amount"); 261 int years = 0; 262 int months = 0; 263 int days = 0; 264 for (TemporalUnit unit : amount.getUnits()) { 265 long unitAmount = amount.get(unit); 266 if (unit == ChronoUnit.YEARS) { 267 years = Math.toIntExact(unitAmount); 268 } else if (unit == ChronoUnit.MONTHS) { 269 months = Math.toIntExact(unitAmount); 270 } else if (unit == ChronoUnit.DAYS) { 271 days = Math.toIntExact(unitAmount); 272 } else { 273 throw new DateTimeException("Unit must be Years, Months or Days, but was " + unit); 274 } 275 } 276 return create(years, months, days); 277 } 278 279 //----------------------------------------------------------------------- 280 /** 281 * Obtains a {@code Period} from a text string such as {@code PnYnMnD}. 282 * <p> 283 * This will parse the string produced by {@code toString()} which is 284 * based on the ISO-8601 period formats {@code PnYnMnD} and {@code PnW}. 285 * <p> 286 * The string starts with an optional sign, denoted by the ASCII negative 287 * or positive symbol. If negative, the whole period is negated. 288 * The ASCII letter "P" is next in upper or lower case. 289 * There are then four sections, each consisting of a number and a suffix. 290 * At least one of the four sections must be present. 291 * The sections have suffixes in ASCII of "Y", "M", "W" and "D" for 292 * years, months, weeks and days, accepted in upper or lower case. 293 * The suffixes must occur in order. 294 * The number part of each section must consist of ASCII digits. 295 * The number may be prefixed by the ASCII negative or positive symbol. 296 * The number must parse to an {@code int}. 297 * <p> 298 * The leading plus/minus sign, and negative values for other units are 299 * not part of the ISO-8601 standard. In addition, ISO-8601 does not 300 * permit mixing between the {@code PnYnMnD} and {@code PnW} formats. 301 * Any week-based input is multiplied by 7 and treated as a number of days. 302 * <p> 303 * For example, the following are valid inputs: 304 * <pre> 305 * "P2Y" -- Period.ofYears(2) 306 * "P3M" -- Period.ofMonths(3) 307 * "P4W" -- Period.ofWeeks(4) 308 * "P5D" -- Period.ofDays(5) 309 * "P1Y2M3D" -- Period.of(1, 2, 3) 310 * "P1Y2M3W4D" -- Period.of(1, 2, 25) 311 * "P-1Y2M" -- Period.of(-1, 2, 0) 312 * "-P1Y2M" -- Period.of(-1, -2, 0) 313 * </pre> 314 * 315 * @param text the text to parse, not null 316 * @return the parsed period, not null 317 * @throws DateTimeParseException if the text cannot be parsed to a period 318 */ parse(CharSequence text)319 public static Period parse(CharSequence text) { 320 Objects.requireNonNull(text, "text"); 321 Matcher matcher = PATTERN.matcher(text); 322 if (matcher.matches()) { 323 int negate = (charMatch(text, matcher.start(1), matcher.end(1), '-') ? -1 : 1); 324 int yearStart = matcher.start(2), yearEnd = matcher.end(2); 325 int monthStart = matcher.start(3), monthEnd = matcher.end(3); 326 int weekStart = matcher.start(4), weekEnd = matcher.end(4); 327 int dayStart = matcher.start(5), dayEnd = matcher.end(5); 328 if (yearStart >= 0 || monthStart >= 0 || weekStart >= 0 || dayStart >= 0) { 329 try { 330 int years = parseNumber(text, yearStart, yearEnd, negate); 331 int months = parseNumber(text, monthStart, monthEnd, negate); 332 int weeks = parseNumber(text, weekStart, weekEnd, negate); 333 int days = parseNumber(text, dayStart, dayEnd, negate); 334 days = Math.addExact(days, Math.multiplyExact(weeks, 7)); 335 return create(years, months, days); 336 } catch (NumberFormatException ex) { 337 throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex); 338 } 339 } 340 } 341 throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0); 342 } 343 charMatch(CharSequence text, int start, int end, char c)344 private static boolean charMatch(CharSequence text, int start, int end, char c) { 345 return (start >= 0 && end == start + 1 && text.charAt(start) == c); 346 } 347 parseNumber(CharSequence text, int start, int end, int negate)348 private static int parseNumber(CharSequence text, int start, int end, int negate) { 349 if (start < 0 || end < 0) { 350 return 0; 351 } 352 int val = Integer.parseInt(text, start, end, 10); 353 try { 354 return Math.multiplyExact(val, negate); 355 } catch (ArithmeticException ex) { 356 throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex); 357 } 358 } 359 360 //----------------------------------------------------------------------- 361 /** 362 * Obtains a {@code Period} consisting of the number of years, months, 363 * and days between two dates. 364 * <p> 365 * The start date is included, but the end date is not. 366 * The period is calculated by removing complete months, then calculating 367 * the remaining number of days, adjusting to ensure that both have the same sign. 368 * The number of months is then split into years and months based on a 12 month year. 369 * A month is considered if the end day-of-month is greater than or equal to the start day-of-month. 370 * For example, from {@code 2010-01-15} to {@code 2011-03-18} is one year, two months and three days. 371 * <p> 372 * The result of this method can be a negative period if the end is before the start. 373 * The negative sign will be the same in each of year, month and day. 374 * 375 * @param startDateInclusive the start date, inclusive, not null 376 * @param endDateExclusive the end date, exclusive, not null 377 * @return the period between this date and the end date, not null 378 * @see ChronoLocalDate#until(ChronoLocalDate) 379 */ between(LocalDate startDateInclusive, LocalDate endDateExclusive)380 public static Period between(LocalDate startDateInclusive, LocalDate endDateExclusive) { 381 return startDateInclusive.until(endDateExclusive); 382 } 383 384 //----------------------------------------------------------------------- 385 /** 386 * Creates an instance. 387 * 388 * @param years the amount 389 * @param months the amount 390 * @param days the amount 391 */ create(int years, int months, int days)392 private static Period create(int years, int months, int days) { 393 if ((years | months | days) == 0) { 394 return ZERO; 395 } 396 return new Period(years, months, days); 397 } 398 399 /** 400 * Constructor. 401 * 402 * @param years the amount 403 * @param months the amount 404 * @param days the amount 405 */ Period(int years, int months, int days)406 private Period(int years, int months, int days) { 407 this.years = years; 408 this.months = months; 409 this.days = days; 410 } 411 412 //----------------------------------------------------------------------- 413 /** 414 * Gets the value of the requested unit. 415 * <p> 416 * This returns a value for each of the three supported units, 417 * {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} and 418 * {@link ChronoUnit#DAYS DAYS}. 419 * All other units throw an exception. 420 * 421 * @param unit the {@code TemporalUnit} for which to return the value 422 * @return the long value of the unit 423 * @throws DateTimeException if the unit is not supported 424 * @throws UnsupportedTemporalTypeException if the unit is not supported 425 */ 426 @Override get(TemporalUnit unit)427 public long get(TemporalUnit unit) { 428 if (unit == ChronoUnit.YEARS) { 429 return getYears(); 430 } else if (unit == ChronoUnit.MONTHS) { 431 return getMonths(); 432 } else if (unit == ChronoUnit.DAYS) { 433 return getDays(); 434 } else { 435 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); 436 } 437 } 438 439 /** 440 * Gets the set of units supported by this period. 441 * <p> 442 * The supported units are {@link ChronoUnit#YEARS YEARS}, 443 * {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. 444 * They are returned in the order years, months, days. 445 * <p> 446 * This set can be used in conjunction with {@link #get(TemporalUnit)} 447 * to access the entire state of the period. 448 * 449 * @return a list containing the years, months and days units, not null 450 */ 451 @Override getUnits()452 public List<TemporalUnit> getUnits() { 453 return SUPPORTED_UNITS; 454 } 455 456 /** 457 * Gets the chronology of this period, which is the ISO calendar system. 458 * <p> 459 * The {@code Chronology} represents the calendar system in use. 460 * The ISO-8601 calendar system is the modern civil calendar system used today 461 * in most of the world. It is equivalent to the proleptic Gregorian calendar 462 * system, in which today's rules for leap years are applied for all time. 463 * 464 * @return the ISO chronology, not null 465 */ 466 @Override getChronology()467 public IsoChronology getChronology() { 468 return IsoChronology.INSTANCE; 469 } 470 471 //----------------------------------------------------------------------- 472 /** 473 * Checks if all three units of this period are zero. 474 * <p> 475 * A zero period has the value zero for the years, months and days units. 476 * 477 * @return true if this period is zero-length 478 */ isZero()479 public boolean isZero() { 480 return (this == ZERO); 481 } 482 483 /** 484 * Checks if any of the three units of this period are negative. 485 * <p> 486 * This checks whether the years, months or days units are less than zero. 487 * 488 * @return true if any unit of this period is negative 489 */ isNegative()490 public boolean isNegative() { 491 return years < 0 || months < 0 || days < 0; 492 } 493 494 //----------------------------------------------------------------------- 495 /** 496 * Gets the amount of years of this period. 497 * <p> 498 * This returns the years unit. 499 * <p> 500 * The months unit is not automatically normalized with the years unit. 501 * This means that a period of "15 months" is different to a period 502 * of "1 year and 3 months". 503 * 504 * @return the amount of years of this period, may be negative 505 */ getYears()506 public int getYears() { 507 return years; 508 } 509 510 /** 511 * Gets the amount of months of this period. 512 * <p> 513 * This returns the months unit. 514 * <p> 515 * The months unit is not automatically normalized with the years unit. 516 * This means that a period of "15 months" is different to a period 517 * of "1 year and 3 months". 518 * 519 * @return the amount of months of this period, may be negative 520 */ getMonths()521 public int getMonths() { 522 return months; 523 } 524 525 /** 526 * Gets the amount of days of this period. 527 * <p> 528 * This returns the days unit. 529 * 530 * @return the amount of days of this period, may be negative 531 */ getDays()532 public int getDays() { 533 return days; 534 } 535 536 //----------------------------------------------------------------------- 537 /** 538 * Returns a copy of this period with the specified amount of years. 539 * <p> 540 * This sets the amount of the years unit in a copy of this period. 541 * The months and days units are unaffected. 542 * <p> 543 * The months unit is not automatically normalized with the years unit. 544 * This means that a period of "15 months" is different to a period 545 * of "1 year and 3 months". 546 * <p> 547 * This instance is immutable and unaffected by this method call. 548 * 549 * @param years the years to represent, may be negative 550 * @return a {@code Period} based on this period with the requested years, not null 551 */ withYears(int years)552 public Period withYears(int years) { 553 if (years == this.years) { 554 return this; 555 } 556 return create(years, months, days); 557 } 558 559 /** 560 * Returns a copy of this period with the specified amount of months. 561 * <p> 562 * This sets the amount of the months unit in a copy of this period. 563 * The years and days units are unaffected. 564 * <p> 565 * The months unit is not automatically normalized with the years unit. 566 * This means that a period of "15 months" is different to a period 567 * of "1 year and 3 months". 568 * <p> 569 * This instance is immutable and unaffected by this method call. 570 * 571 * @param months the months to represent, may be negative 572 * @return a {@code Period} based on this period with the requested months, not null 573 */ withMonths(int months)574 public Period withMonths(int months) { 575 if (months == this.months) { 576 return this; 577 } 578 return create(years, months, days); 579 } 580 581 /** 582 * Returns a copy of this period with the specified amount of days. 583 * <p> 584 * This sets the amount of the days unit in a copy of this period. 585 * The years and months units are unaffected. 586 * <p> 587 * This instance is immutable and unaffected by this method call. 588 * 589 * @param days the days to represent, may be negative 590 * @return a {@code Period} based on this period with the requested days, not null 591 */ withDays(int days)592 public Period withDays(int days) { 593 if (days == this.days) { 594 return this; 595 } 596 return create(years, months, days); 597 } 598 599 //----------------------------------------------------------------------- 600 /** 601 * Returns a copy of this period with the specified period added. 602 * <p> 603 * This operates separately on the years, months and days. 604 * No normalization is performed. 605 * <p> 606 * For example, "1 year, 6 months and 3 days" plus "2 years, 2 months and 2 days" 607 * returns "3 years, 8 months and 5 days". 608 * <p> 609 * The specified amount is typically an instance of {@code Period}. 610 * Other types are interpreted using {@link Period#from(TemporalAmount)}. 611 * <p> 612 * This instance is immutable and unaffected by this method call. 613 * 614 * @param amountToAdd the amount to add, not null 615 * @return a {@code Period} based on this period with the requested period added, not null 616 * @throws DateTimeException if the specified amount has a non-ISO chronology or 617 * contains an invalid unit 618 * @throws ArithmeticException if numeric overflow occurs 619 */ plus(TemporalAmount amountToAdd)620 public Period plus(TemporalAmount amountToAdd) { 621 Period isoAmount = Period.from(amountToAdd); 622 return create( 623 Math.addExact(years, isoAmount.years), 624 Math.addExact(months, isoAmount.months), 625 Math.addExact(days, isoAmount.days)); 626 } 627 628 /** 629 * Returns a copy of this period with the specified years added. 630 * <p> 631 * This adds the amount to the years unit in a copy of this period. 632 * The months and days units are unaffected. 633 * For example, "1 year, 6 months and 3 days" plus 2 years returns "3 years, 6 months and 3 days". 634 * <p> 635 * This instance is immutable and unaffected by this method call. 636 * 637 * @param yearsToAdd the years to add, positive or negative 638 * @return a {@code Period} based on this period with the specified years added, not null 639 * @throws ArithmeticException if numeric overflow occurs 640 */ plusYears(long yearsToAdd)641 public Period plusYears(long yearsToAdd) { 642 if (yearsToAdd == 0) { 643 return this; 644 } 645 return create(Math.toIntExact(Math.addExact(years, yearsToAdd)), months, days); 646 } 647 648 /** 649 * Returns a copy of this period with the specified months added. 650 * <p> 651 * This adds the amount to the months unit in a copy of this period. 652 * The years and days units are unaffected. 653 * For example, "1 year, 6 months and 3 days" plus 2 months returns "1 year, 8 months and 3 days". 654 * <p> 655 * This instance is immutable and unaffected by this method call. 656 * 657 * @param monthsToAdd the months to add, positive or negative 658 * @return a {@code Period} based on this period with the specified months added, not null 659 * @throws ArithmeticException if numeric overflow occurs 660 */ plusMonths(long monthsToAdd)661 public Period plusMonths(long monthsToAdd) { 662 if (monthsToAdd == 0) { 663 return this; 664 } 665 return create(years, Math.toIntExact(Math.addExact(months, monthsToAdd)), days); 666 } 667 668 /** 669 * Returns a copy of this period with the specified days added. 670 * <p> 671 * This adds the amount to the days unit in a copy of this period. 672 * The years and months units are unaffected. 673 * For example, "1 year, 6 months and 3 days" plus 2 days returns "1 year, 6 months and 5 days". 674 * <p> 675 * This instance is immutable and unaffected by this method call. 676 * 677 * @param daysToAdd the days to add, positive or negative 678 * @return a {@code Period} based on this period with the specified days added, not null 679 * @throws ArithmeticException if numeric overflow occurs 680 */ plusDays(long daysToAdd)681 public Period plusDays(long daysToAdd) { 682 if (daysToAdd == 0) { 683 return this; 684 } 685 return create(years, months, Math.toIntExact(Math.addExact(days, daysToAdd))); 686 } 687 688 //----------------------------------------------------------------------- 689 /** 690 * Returns a copy of this period with the specified period subtracted. 691 * <p> 692 * This operates separately on the years, months and days. 693 * No normalization is performed. 694 * <p> 695 * For example, "1 year, 6 months and 3 days" minus "2 years, 2 months and 2 days" 696 * returns "-1 years, 4 months and 1 day". 697 * <p> 698 * The specified amount is typically an instance of {@code Period}. 699 * Other types are interpreted using {@link Period#from(TemporalAmount)}. 700 * <p> 701 * This instance is immutable and unaffected by this method call. 702 * 703 * @param amountToSubtract the amount to subtract, not null 704 * @return a {@code Period} based on this period with the requested period subtracted, not null 705 * @throws DateTimeException if the specified amount has a non-ISO chronology or 706 * contains an invalid unit 707 * @throws ArithmeticException if numeric overflow occurs 708 */ minus(TemporalAmount amountToSubtract)709 public Period minus(TemporalAmount amountToSubtract) { 710 Period isoAmount = Period.from(amountToSubtract); 711 return create( 712 Math.subtractExact(years, isoAmount.years), 713 Math.subtractExact(months, isoAmount.months), 714 Math.subtractExact(days, isoAmount.days)); 715 } 716 717 /** 718 * Returns a copy of this period with the specified years subtracted. 719 * <p> 720 * This subtracts the amount from the years unit in a copy of this period. 721 * The months and days units are unaffected. 722 * For example, "1 year, 6 months and 3 days" minus 2 years returns "-1 years, 6 months and 3 days". 723 * <p> 724 * This instance is immutable and unaffected by this method call. 725 * 726 * @param yearsToSubtract the years to subtract, positive or negative 727 * @return a {@code Period} based on this period with the specified years subtracted, not null 728 * @throws ArithmeticException if numeric overflow occurs 729 */ minusYears(long yearsToSubtract)730 public Period minusYears(long yearsToSubtract) { 731 return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract)); 732 } 733 734 /** 735 * Returns a copy of this period with the specified months subtracted. 736 * <p> 737 * This subtracts the amount from the months unit in a copy of this period. 738 * The years and days units are unaffected. 739 * For example, "1 year, 6 months and 3 days" minus 2 months returns "1 year, 4 months and 3 days". 740 * <p> 741 * This instance is immutable and unaffected by this method call. 742 * 743 * @param monthsToSubtract the years to subtract, positive or negative 744 * @return a {@code Period} based on this period with the specified months subtracted, not null 745 * @throws ArithmeticException if numeric overflow occurs 746 */ minusMonths(long monthsToSubtract)747 public Period minusMonths(long monthsToSubtract) { 748 return (monthsToSubtract == Long.MIN_VALUE ? plusMonths(Long.MAX_VALUE).plusMonths(1) : plusMonths(-monthsToSubtract)); 749 } 750 751 /** 752 * Returns a copy of this period with the specified days subtracted. 753 * <p> 754 * This subtracts the amount from the days unit in a copy of this period. 755 * The years and months units are unaffected. 756 * For example, "1 year, 6 months and 3 days" minus 2 days returns "1 year, 6 months and 1 day". 757 * <p> 758 * This instance is immutable and unaffected by this method call. 759 * 760 * @param daysToSubtract the months to subtract, positive or negative 761 * @return a {@code Period} based on this period with the specified days subtracted, not null 762 * @throws ArithmeticException if numeric overflow occurs 763 */ minusDays(long daysToSubtract)764 public Period minusDays(long daysToSubtract) { 765 return (daysToSubtract == Long.MIN_VALUE ? plusDays(Long.MAX_VALUE).plusDays(1) : plusDays(-daysToSubtract)); 766 } 767 768 //----------------------------------------------------------------------- 769 /** 770 * Returns a new instance with each element in this period multiplied 771 * by the specified scalar. 772 * <p> 773 * This returns a period with each of the years, months and days units 774 * individually multiplied. 775 * For example, a period of "2 years, -3 months and 4 days" multiplied by 776 * 3 will return "6 years, -9 months and 12 days". 777 * No normalization is performed. 778 * 779 * @param scalar the scalar to multiply by, not null 780 * @return a {@code Period} based on this period with the amounts multiplied by the scalar, not null 781 * @throws ArithmeticException if numeric overflow occurs 782 */ multipliedBy(int scalar)783 public Period multipliedBy(int scalar) { 784 if (this == ZERO || scalar == 1) { 785 return this; 786 } 787 return create( 788 Math.multiplyExact(years, scalar), 789 Math.multiplyExact(months, scalar), 790 Math.multiplyExact(days, scalar)); 791 } 792 793 /** 794 * Returns a new instance with each amount in this period negated. 795 * <p> 796 * This returns a period with each of the years, months and days units 797 * individually negated. 798 * For example, a period of "2 years, -3 months and 4 days" will be 799 * negated to "-2 years, 3 months and -4 days". 800 * No normalization is performed. 801 * 802 * @return a {@code Period} based on this period with the amounts negated, not null 803 * @throws ArithmeticException if numeric overflow occurs, which only happens if 804 * one of the units has the value {@code Long.MIN_VALUE} 805 */ negated()806 public Period negated() { 807 return multipliedBy(-1); 808 } 809 810 //----------------------------------------------------------------------- 811 /** 812 * Returns a copy of this period with the years and months normalized. 813 * <p> 814 * This normalizes the years and months units, leaving the days unit unchanged. 815 * The months unit is adjusted to have an absolute value less than 12, 816 * with the years unit being adjusted to compensate. For example, a period of 817 * "1 Year and 15 months" will be normalized to "2 years and 3 months". 818 * <p> 819 * The sign of the years and months units will be the same after normalization. 820 * For example, a period of "1 year and -25 months" will be normalized to 821 * "-1 year and -1 month". 822 * <p> 823 * This instance is immutable and unaffected by this method call. 824 * 825 * @return a {@code Period} based on this period with excess months normalized to years, not null 826 * @throws ArithmeticException if numeric overflow occurs 827 */ normalized()828 public Period normalized() { 829 long totalMonths = toTotalMonths(); 830 long splitYears = totalMonths / 12; 831 int splitMonths = (int) (totalMonths % 12); // no overflow 832 if (splitYears == years && splitMonths == months) { 833 return this; 834 } 835 return create(Math.toIntExact(splitYears), splitMonths, days); 836 } 837 838 /** 839 * Gets the total number of months in this period. 840 * <p> 841 * This returns the total number of months in the period by multiplying the 842 * number of years by 12 and adding the number of months. 843 * <p> 844 * This instance is immutable and unaffected by this method call. 845 * 846 * @return the total number of months in the period, may be negative 847 */ toTotalMonths()848 public long toTotalMonths() { 849 return years * 12L + months; // no overflow 850 } 851 852 //------------------------------------------------------------------------- 853 /** 854 * Adds this period to the specified temporal object. 855 * <p> 856 * This returns a temporal object of the same observable type as the input 857 * with this period added. 858 * If the temporal has a chronology, it must be the ISO chronology. 859 * <p> 860 * In most cases, it is clearer to reverse the calling pattern by using 861 * {@link Temporal#plus(TemporalAmount)}. 862 * <pre> 863 * // these two lines are equivalent, but the second approach is recommended 864 * dateTime = thisPeriod.addTo(dateTime); 865 * dateTime = dateTime.plus(thisPeriod); 866 * </pre> 867 * <p> 868 * The calculation operates as follows. 869 * First, the chronology of the temporal is checked to ensure it is ISO chronology or null. 870 * Second, if the months are zero, the years are added if non-zero, otherwise 871 * the combination of years and months is added if non-zero. 872 * Finally, any days are added. 873 * <p> 874 * This approach ensures that a partial period can be added to a partial date. 875 * For example, a period of years and/or months can be added to a {@code YearMonth}, 876 * but a period including days cannot. 877 * The approach also adds years and months together when necessary, which ensures 878 * correct behaviour at the end of the month. 879 * <p> 880 * This instance is immutable and unaffected by this method call. 881 * 882 * @param temporal the temporal object to adjust, not null 883 * @return an object of the same type with the adjustment made, not null 884 * @throws DateTimeException if unable to add 885 * @throws ArithmeticException if numeric overflow occurs 886 */ 887 @Override addTo(Temporal temporal)888 public Temporal addTo(Temporal temporal) { 889 validateChrono(temporal); 890 if (months == 0) { 891 if (years != 0) { 892 temporal = temporal.plus(years, YEARS); 893 } 894 } else { 895 long totalMonths = toTotalMonths(); 896 if (totalMonths != 0) { 897 temporal = temporal.plus(totalMonths, MONTHS); 898 } 899 } 900 if (days != 0) { 901 temporal = temporal.plus(days, DAYS); 902 } 903 return temporal; 904 } 905 906 /** 907 * Subtracts this period from the specified temporal object. 908 * <p> 909 * This returns a temporal object of the same observable type as the input 910 * with this period subtracted. 911 * If the temporal has a chronology, it must be the ISO chronology. 912 * <p> 913 * In most cases, it is clearer to reverse the calling pattern by using 914 * {@link Temporal#minus(TemporalAmount)}. 915 * <pre> 916 * // these two lines are equivalent, but the second approach is recommended 917 * dateTime = thisPeriod.subtractFrom(dateTime); 918 * dateTime = dateTime.minus(thisPeriod); 919 * </pre> 920 * <p> 921 * The calculation operates as follows. 922 * First, the chronology of the temporal is checked to ensure it is ISO chronology or null. 923 * Second, if the months are zero, the years are subtracted if non-zero, otherwise 924 * the combination of years and months is subtracted if non-zero. 925 * Finally, any days are subtracted. 926 * <p> 927 * This approach ensures that a partial period can be subtracted from a partial date. 928 * For example, a period of years and/or months can be subtracted from a {@code YearMonth}, 929 * but a period including days cannot. 930 * The approach also subtracts years and months together when necessary, which ensures 931 * correct behaviour at the end of the month. 932 * <p> 933 * This instance is immutable and unaffected by this method call. 934 * 935 * @param temporal the temporal object to adjust, not null 936 * @return an object of the same type with the adjustment made, not null 937 * @throws DateTimeException if unable to subtract 938 * @throws ArithmeticException if numeric overflow occurs 939 */ 940 @Override subtractFrom(Temporal temporal)941 public Temporal subtractFrom(Temporal temporal) { 942 validateChrono(temporal); 943 if (months == 0) { 944 if (years != 0) { 945 temporal = temporal.minus(years, YEARS); 946 } 947 } else { 948 long totalMonths = toTotalMonths(); 949 if (totalMonths != 0) { 950 temporal = temporal.minus(totalMonths, MONTHS); 951 } 952 } 953 if (days != 0) { 954 temporal = temporal.minus(days, DAYS); 955 } 956 return temporal; 957 } 958 959 /** 960 * Validates that the temporal has the correct chronology. 961 */ validateChrono(TemporalAccessor temporal)962 private void validateChrono(TemporalAccessor temporal) { 963 Objects.requireNonNull(temporal, "temporal"); 964 Chronology temporalChrono = temporal.query(TemporalQueries.chronology()); 965 if (temporalChrono != null && IsoChronology.INSTANCE.equals(temporalChrono) == false) { 966 throw new DateTimeException("Chronology mismatch, expected: ISO, actual: " + temporalChrono.getId()); 967 } 968 } 969 970 //----------------------------------------------------------------------- 971 /** 972 * Checks if this period is equal to another period. 973 * <p> 974 * The comparison is based on the type {@code Period} and each of the three amounts. 975 * To be equal, the years, months and days units must be individually equal. 976 * Note that this means that a period of "15 Months" is not equal to a period 977 * of "1 Year and 3 Months". 978 * 979 * @param obj the object to check, null returns false 980 * @return true if this is equal to the other period 981 */ 982 @Override equals(Object obj)983 public boolean equals(Object obj) { 984 if (this == obj) { 985 return true; 986 } 987 if (obj instanceof Period) { 988 Period other = (Period) obj; 989 return years == other.years && 990 months == other.months && 991 days == other.days; 992 } 993 return false; 994 } 995 996 /** 997 * A hash code for this period. 998 * 999 * @return a suitable hash code 1000 */ 1001 @Override hashCode()1002 public int hashCode() { 1003 return years + Integer.rotateLeft(months, 8) + Integer.rotateLeft(days, 16); 1004 } 1005 1006 //----------------------------------------------------------------------- 1007 /** 1008 * Outputs this period as a {@code String}, such as {@code P6Y3M1D}. 1009 * <p> 1010 * The output will be in the ISO-8601 period format. 1011 * A zero period will be represented as zero days, 'P0D'. 1012 * 1013 * @return a string representation of this period, not null 1014 */ 1015 @Override toString()1016 public String toString() { 1017 if (this == ZERO) { 1018 return "P0D"; 1019 } else { 1020 StringBuilder buf = new StringBuilder(); 1021 buf.append('P'); 1022 if (years != 0) { 1023 buf.append(years).append('Y'); 1024 } 1025 if (months != 0) { 1026 buf.append(months).append('M'); 1027 } 1028 if (days != 0) { 1029 buf.append(days).append('D'); 1030 } 1031 return buf.toString(); 1032 } 1033 } 1034 1035 //----------------------------------------------------------------------- 1036 /** 1037 * Writes the object using a 1038 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>. 1039 * @serialData 1040 * <pre> 1041 * out.writeByte(14); // identifies a Period 1042 * out.writeInt(years); 1043 * out.writeInt(months); 1044 * out.writeInt(days); 1045 * </pre> 1046 * 1047 * @return the instance of {@code Ser}, not null 1048 */ writeReplace()1049 private Object writeReplace() { 1050 return new Ser(Ser.PERIOD_TYPE, this); 1051 } 1052 1053 /** 1054 * Defend against malicious streams. 1055 * 1056 * @param s the stream to read 1057 * @throws java.io.InvalidObjectException always 1058 */ readObject(ObjectInputStream s)1059 private void readObject(ObjectInputStream s) throws InvalidObjectException { 1060 throw new InvalidObjectException("Deserialization via serialization delegate"); 1061 } 1062 writeExternal(DataOutput out)1063 void writeExternal(DataOutput out) throws IOException { 1064 out.writeInt(years); 1065 out.writeInt(months); 1066 out.writeInt(days); 1067 } 1068 readExternal(DataInput in)1069 static Period readExternal(DataInput in) throws IOException { 1070 int years = in.readInt(); 1071 int months = in.readInt(); 1072 int days = in.readInt(); 1073 return Period.of(years, months, days); 1074 } 1075 1076 } 1077