1 /* 2 * Copyright (c) 2012, 2015, 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.Arrays; 87 import java.util.Collections; 88 import java.util.List; 89 import java.util.Objects; 90 import java.util.regex.Matcher; 91 import java.util.regex.Pattern; 92 93 // Android-changed: removed ValueBased paragraph. 94 /** 95 * A date-based amount of time in the ISO-8601 calendar system, 96 * such as '2 years, 3 months and 4 days'. 97 * <p> 98 * This class models a quantity or amount of time in terms of years, months and days. 99 * See {@link Duration} for the time-based equivalent to this class. 100 * <p> 101 * Durations and periods differ in their treatment of daylight savings time 102 * when added to {@link ZonedDateTime}. A {@code Duration} will add an exact 103 * number of seconds, thus a duration of one day is always exactly 24 hours. 104 * By contrast, a {@code Period} will add a conceptual day, trying to maintain 105 * the local time. 106 * <p> 107 * For example, consider adding a period of one day and a duration of one day to 108 * 18:00 on the evening before a daylight savings gap. The {@code Period} will add 109 * the conceptual day and result in a {@code ZonedDateTime} at 18:00 the following day. 110 * By contrast, the {@code Duration} will add exactly 24 hours, resulting in a 111 * {@code ZonedDateTime} at 19:00 the following day (assuming a one hour DST gap). 112 * <p> 113 * The supported units of a period are {@link ChronoUnit#YEARS YEARS}, 114 * {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. 115 * All three fields are always present, but may be set to zero. 116 * <p> 117 * The ISO-8601 calendar system is the modern civil calendar system used today 118 * in most of the world. It is equivalent to the proleptic Gregorian calendar 119 * system, in which today's rules for leap years are applied for all time. 120 * <p> 121 * The period is modeled as a directed amount of time, meaning that individual parts of the 122 * period may be negative. 123 * 124 * @implSpec 125 * This class is immutable and thread-safe. 126 * 127 * @since 1.8 128 */ 129 public final class Period 130 implements ChronoPeriod, Serializable { 131 132 /** 133 * A constant for a period of zero. 134 */ 135 public static final Period ZERO = new Period(0, 0, 0); 136 /** 137 * Serialization version. 138 */ 139 private static final long serialVersionUID = -3587258372562876L; 140 /** 141 * The pattern for parsing. 142 */ 143 private static final Pattern PATTERN = 144 Pattern.compile("([-+]?)P(?:([-+]?[0-9]+)Y)?(?:([-+]?[0-9]+)M)?(?:([-+]?[0-9]+)W)?(?:([-+]?[0-9]+)D)?", Pattern.CASE_INSENSITIVE); 145 146 /** 147 * The set of supported units. 148 */ 149 private static final List<TemporalUnit> SUPPORTED_UNITS = 150 Collections.unmodifiableList(Arrays.<TemporalUnit>asList(YEARS, MONTHS, DAYS)); 151 152 /** 153 * The number of years. 154 */ 155 private final int years; 156 /** 157 * The number of months. 158 */ 159 private final int months; 160 /** 161 * The number of days. 162 */ 163 private final int days; 164 165 //----------------------------------------------------------------------- 166 /** 167 * Obtains a {@code Period} representing a number of years. 168 * <p> 169 * The resulting period will have the specified years. 170 * The months and days units will be zero. 171 * 172 * @param years the number of years, positive or negative 173 * @return the period of years, not null 174 */ ofYears(int years)175 public static Period ofYears(int years) { 176 return create(years, 0, 0); 177 } 178 179 /** 180 * Obtains a {@code Period} representing a number of months. 181 * <p> 182 * The resulting period will have the specified months. 183 * The years and days units will be zero. 184 * 185 * @param months the number of months, positive or negative 186 * @return the period of months, not null 187 */ ofMonths(int months)188 public static Period ofMonths(int months) { 189 return create(0, months, 0); 190 } 191 192 /** 193 * Obtains a {@code Period} representing a number of weeks. 194 * <p> 195 * The resulting period will be day-based, with the amount of days 196 * equal to the number of weeks multiplied by 7. 197 * The years and months units will be zero. 198 * 199 * @param weeks the number of weeks, positive or negative 200 * @return the period, with the input weeks converted to days, not null 201 */ ofWeeks(int weeks)202 public static Period ofWeeks(int weeks) { 203 return create(0, 0, Math.multiplyExact(weeks, 7)); 204 } 205 206 /** 207 * Obtains a {@code Period} representing a number of days. 208 * <p> 209 * The resulting period will have the specified days. 210 * The years and months units will be zero. 211 * 212 * @param days the number of days, positive or negative 213 * @return the period of days, not null 214 */ ofDays(int days)215 public static Period ofDays(int days) { 216 return create(0, 0, days); 217 } 218 219 //----------------------------------------------------------------------- 220 /** 221 * Obtains a {@code Period} representing a number of years, months and days. 222 * <p> 223 * This creates an instance based on years, months and days. 224 * 225 * @param years the amount of years, may be negative 226 * @param months the amount of months, may be negative 227 * @param days the amount of days, may be negative 228 * @return the period of years, months and days, not null 229 */ of(int years, int months, int days)230 public static Period of(int years, int months, int days) { 231 return create(years, months, days); 232 } 233 234 //----------------------------------------------------------------------- 235 /** 236 * Obtains an instance of {@code Period} from a temporal amount. 237 * <p> 238 * This obtains a period based on the specified amount. 239 * A {@code TemporalAmount} represents an amount of time, which may be 240 * date-based or time-based, which this factory extracts to a {@code Period}. 241 * <p> 242 * The conversion loops around the set of units from the amount and uses 243 * the {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} 244 * and {@link ChronoUnit#DAYS DAYS} units to create a period. 245 * If any other units are found then an exception is thrown. 246 * <p> 247 * If the amount is a {@code ChronoPeriod} then it must use the ISO chronology. 248 * 249 * @param amount the temporal amount to convert, not null 250 * @return the equivalent period, not null 251 * @throws DateTimeException if unable to convert to a {@code Period} 252 * @throws ArithmeticException if the amount of years, months or days exceeds an int 253 */ from(TemporalAmount amount)254 public static Period from(TemporalAmount amount) { 255 if (amount instanceof Period) { 256 return (Period) amount; 257 } 258 if (amount instanceof ChronoPeriod) { 259 if (IsoChronology.INSTANCE.equals(((ChronoPeriod) amount).getChronology()) == false) { 260 throw new DateTimeException("Period requires ISO chronology: " + amount); 261 } 262 } 263 Objects.requireNonNull(amount, "amount"); 264 int years = 0; 265 int months = 0; 266 int days = 0; 267 for (TemporalUnit unit : amount.getUnits()) { 268 long unitAmount = amount.get(unit); 269 if (unit == ChronoUnit.YEARS) { 270 years = Math.toIntExact(unitAmount); 271 } else if (unit == ChronoUnit.MONTHS) { 272 months = Math.toIntExact(unitAmount); 273 } else if (unit == ChronoUnit.DAYS) { 274 days = Math.toIntExact(unitAmount); 275 } else { 276 throw new DateTimeException("Unit must be Years, Months or Days, but was " + unit); 277 } 278 } 279 return create(years, months, days); 280 } 281 282 //----------------------------------------------------------------------- 283 /** 284 * Obtains a {@code Period} from a text string such as {@code PnYnMnD}. 285 * <p> 286 * This will parse the string produced by {@code toString()} which is 287 * based on the ISO-8601 period formats {@code PnYnMnD} and {@code PnW}. 288 * <p> 289 * The string starts with an optional sign, denoted by the ASCII negative 290 * or positive symbol. If negative, the whole period is negated. 291 * The ASCII letter "P" is next in upper or lower case. 292 * There are then four sections, each consisting of a number and a suffix. 293 * At least one of the four sections must be present. 294 * The sections have suffixes in ASCII of "Y", "M", "W" and "D" for 295 * years, months, weeks and days, accepted in upper or lower case. 296 * The suffixes must occur in order. 297 * The number part of each section must consist of ASCII digits. 298 * The number may be prefixed by the ASCII negative or positive symbol. 299 * The number must parse to an {@code int}. 300 * <p> 301 * The leading plus/minus sign, and negative values for other units are 302 * not part of the ISO-8601 standard. In addition, ISO-8601 does not 303 * permit mixing between the {@code PnYnMnD} and {@code PnW} formats. 304 * Any week-based input is multiplied by 7 and treated as a number of days. 305 * <p> 306 * For example, the following are valid inputs: 307 * <pre> 308 * "P2Y" -- Period.ofYears(2) 309 * "P3M" -- Period.ofMonths(3) 310 * "P4W" -- Period.ofWeeks(4) 311 * "P5D" -- Period.ofDays(5) 312 * "P1Y2M3D" -- Period.of(1, 2, 3) 313 * "P1Y2M3W4D" -- Period.of(1, 2, 25) 314 * "P-1Y2M" -- Period.of(-1, 2, 0) 315 * "-P1Y2M" -- Period.of(-1, -2, 0) 316 * </pre> 317 * 318 * @param text the text to parse, not null 319 * @return the parsed period, not null 320 * @throws DateTimeParseException if the text cannot be parsed to a period 321 */ parse(CharSequence text)322 public static Period parse(CharSequence text) { 323 Objects.requireNonNull(text, "text"); 324 Matcher matcher = PATTERN.matcher(text); 325 if (matcher.matches()) { 326 int negate = ("-".equals(matcher.group(1)) ? -1 : 1); 327 String yearMatch = matcher.group(2); 328 String monthMatch = matcher.group(3); 329 String weekMatch = matcher.group(4); 330 String dayMatch = matcher.group(5); 331 if (yearMatch != null || monthMatch != null || dayMatch != null || weekMatch != null) { 332 try { 333 int years = parseNumber(text, yearMatch, negate); 334 int months = parseNumber(text, monthMatch, negate); 335 int weeks = parseNumber(text, weekMatch, negate); 336 int days = parseNumber(text, dayMatch, negate); 337 days = Math.addExact(days, Math.multiplyExact(weeks, 7)); 338 return create(years, months, days); 339 } catch (NumberFormatException ex) { 340 throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex); 341 } 342 } 343 } 344 throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0); 345 } 346 parseNumber(CharSequence text, String str, int negate)347 private static int parseNumber(CharSequence text, String str, int negate) { 348 if (str == null) { 349 return 0; 350 } 351 int val = Integer.parseInt(str); 352 try { 353 return Math.multiplyExact(val, negate); 354 } catch (ArithmeticException ex) { 355 throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex); 356 } 357 } 358 359 //----------------------------------------------------------------------- 360 /** 361 * Obtains a {@code Period} consisting of the number of years, months, 362 * and days between two dates. 363 * <p> 364 * The start date is included, but the end date is not. 365 * The period is calculated by removing complete months, then calculating 366 * the remaining number of days, adjusting to ensure that both have the same sign. 367 * The number of months is then split into years and months based on a 12 month year. 368 * A month is considered if the end day-of-month is greater than or equal to the start day-of-month. 369 * For example, from {@code 2010-01-15} to {@code 2011-03-18} is one year, two months and three days. 370 * <p> 371 * The result of this method can be a negative period if the end is before the start. 372 * The negative sign will be the same in each of year, month and day. 373 * 374 * @param startDateInclusive the start date, inclusive, not null 375 * @param endDateExclusive the end date, exclusive, not null 376 * @return the period between this date and the end date, not null 377 * @see ChronoLocalDate#until(ChronoLocalDate) 378 */ between(LocalDate startDateInclusive, LocalDate endDateExclusive)379 public static Period between(LocalDate startDateInclusive, LocalDate endDateExclusive) { 380 return startDateInclusive.until(endDateExclusive); 381 } 382 383 //----------------------------------------------------------------------- 384 /** 385 * Creates an instance. 386 * 387 * @param years the amount 388 * @param months the amount 389 * @param days the amount 390 */ create(int years, int months, int days)391 private static Period create(int years, int months, int days) { 392 if ((years | months | days) == 0) { 393 return ZERO; 394 } 395 return new Period(years, months, days); 396 } 397 398 /** 399 * Constructor. 400 * 401 * @param years the amount 402 * @param months the amount 403 * @param days the amount 404 */ Period(int years, int months, int days)405 private Period(int years, int months, int days) { 406 this.years = years; 407 this.months = months; 408 this.days = days; 409 } 410 411 //----------------------------------------------------------------------- 412 /** 413 * Gets the value of the requested unit. 414 * <p> 415 * This returns a value for each of the three supported units, 416 * {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} and 417 * {@link ChronoUnit#DAYS DAYS}. 418 * All other units throw an exception. 419 * 420 * @param unit the {@code TemporalUnit} for which to return the value 421 * @return the long value of the unit 422 * @throws DateTimeException if the unit is not supported 423 * @throws UnsupportedTemporalTypeException if the unit is not supported 424 */ 425 @Override get(TemporalUnit unit)426 public long get(TemporalUnit unit) { 427 if (unit == ChronoUnit.YEARS) { 428 return getYears(); 429 } else if (unit == ChronoUnit.MONTHS) { 430 return getMonths(); 431 } else if (unit == ChronoUnit.DAYS) { 432 return getDays(); 433 } else { 434 throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); 435 } 436 } 437 438 /** 439 * Gets the set of units supported by this period. 440 * <p> 441 * The supported units are {@link ChronoUnit#YEARS YEARS}, 442 * {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. 443 * They are returned in the order years, months, days. 444 * <p> 445 * This set can be used in conjunction with {@link #get(TemporalUnit)} 446 * to access the entire state of the period. 447 * 448 * @return a list containing the years, months and days units, not null 449 */ 450 @Override getUnits()451 public List<TemporalUnit> getUnits() { 452 return SUPPORTED_UNITS; 453 } 454 455 /** 456 * Gets the chronology of this period, which is the ISO calendar system. 457 * <p> 458 * The {@code Chronology} represents the calendar system in use. 459 * The ISO-8601 calendar system is the modern civil calendar system used today 460 * in most of the world. It is equivalent to the proleptic Gregorian calendar 461 * system, in which today's rules for leap years are applied for all time. 462 * 463 * @return the ISO chronology, not null 464 */ 465 @Override getChronology()466 public IsoChronology getChronology() { 467 return IsoChronology.INSTANCE; 468 } 469 470 //----------------------------------------------------------------------- 471 /** 472 * Checks if all three units of this period are zero. 473 * <p> 474 * A zero period has the value zero for the years, months and days units. 475 * 476 * @return true if this period is zero-length 477 */ isZero()478 public boolean isZero() { 479 return (this == ZERO); 480 } 481 482 /** 483 * Checks if any of the three units of this period are negative. 484 * <p> 485 * This checks whether the years, months or days units are less than zero. 486 * 487 * @return true if any unit of this period is negative 488 */ isNegative()489 public boolean isNegative() { 490 return years < 0 || months < 0 || days < 0; 491 } 492 493 //----------------------------------------------------------------------- 494 /** 495 * Gets the amount of years of this period. 496 * <p> 497 * This returns the years unit. 498 * <p> 499 * The months unit is not automatically normalized with the years unit. 500 * This means that a period of "15 months" is different to a period 501 * of "1 year and 3 months". 502 * 503 * @return the amount of years of this period, may be negative 504 */ getYears()505 public int getYears() { 506 return years; 507 } 508 509 /** 510 * Gets the amount of months of this period. 511 * <p> 512 * This returns the months unit. 513 * <p> 514 * The months unit is not automatically normalized with the years unit. 515 * This means that a period of "15 months" is different to a period 516 * of "1 year and 3 months". 517 * 518 * @return the amount of months of this period, may be negative 519 */ getMonths()520 public int getMonths() { 521 return months; 522 } 523 524 /** 525 * Gets the amount of days of this period. 526 * <p> 527 * This returns the days unit. 528 * 529 * @return the amount of days of this period, may be negative 530 */ getDays()531 public int getDays() { 532 return days; 533 } 534 535 //----------------------------------------------------------------------- 536 /** 537 * Returns a copy of this period with the specified amount of years. 538 * <p> 539 * This sets the amount of the years unit in a copy of this period. 540 * The months and days units are unaffected. 541 * <p> 542 * The months unit is not automatically normalized with the years unit. 543 * This means that a period of "15 months" is different to a period 544 * of "1 year and 3 months". 545 * <p> 546 * This instance is immutable and unaffected by this method call. 547 * 548 * @param years the years to represent, may be negative 549 * @return a {@code Period} based on this period with the requested years, not null 550 */ withYears(int years)551 public Period withYears(int years) { 552 if (years == this.years) { 553 return this; 554 } 555 return create(years, months, days); 556 } 557 558 /** 559 * Returns a copy of this period with the specified amount of months. 560 * <p> 561 * This sets the amount of the months unit in a copy of this period. 562 * The years and days units are unaffected. 563 * <p> 564 * The months unit is not automatically normalized with the years unit. 565 * This means that a period of "15 months" is different to a period 566 * of "1 year and 3 months". 567 * <p> 568 * This instance is immutable and unaffected by this method call. 569 * 570 * @param months the months to represent, may be negative 571 * @return a {@code Period} based on this period with the requested months, not null 572 */ withMonths(int months)573 public Period withMonths(int months) { 574 if (months == this.months) { 575 return this; 576 } 577 return create(years, months, days); 578 } 579 580 /** 581 * Returns a copy of this period with the specified amount of days. 582 * <p> 583 * This sets the amount of the days unit in a copy of this period. 584 * The years and months units are unaffected. 585 * <p> 586 * This instance is immutable and unaffected by this method call. 587 * 588 * @param days the days to represent, may be negative 589 * @return a {@code Period} based on this period with the requested days, not null 590 */ withDays(int days)591 public Period withDays(int days) { 592 if (days == this.days) { 593 return this; 594 } 595 return create(years, months, days); 596 } 597 598 //----------------------------------------------------------------------- 599 /** 600 * Returns a copy of this period with the specified period added. 601 * <p> 602 * This operates separately on the years, months and days. 603 * No normalization is performed. 604 * <p> 605 * For example, "1 year, 6 months and 3 days" plus "2 years, 2 months and 2 days" 606 * returns "3 years, 8 months and 5 days". 607 * <p> 608 * The specified amount is typically an instance of {@code Period}. 609 * Other types are interpreted using {@link Period#from(TemporalAmount)}. 610 * <p> 611 * This instance is immutable and unaffected by this method call. 612 * 613 * @param amountToAdd the amount to add, not null 614 * @return a {@code Period} based on this period with the requested period added, not null 615 * @throws DateTimeException if the specified amount has a non-ISO chronology or 616 * contains an invalid unit 617 * @throws ArithmeticException if numeric overflow occurs 618 */ plus(TemporalAmount amountToAdd)619 public Period plus(TemporalAmount amountToAdd) { 620 Period isoAmount = Period.from(amountToAdd); 621 return create( 622 Math.addExact(years, isoAmount.years), 623 Math.addExact(months, isoAmount.months), 624 Math.addExact(days, isoAmount.days)); 625 } 626 627 /** 628 * Returns a copy of this period with the specified years added. 629 * <p> 630 * This adds the amount to the years unit in a copy of this period. 631 * The months and days units are unaffected. 632 * For example, "1 year, 6 months and 3 days" plus 2 years returns "3 years, 6 months and 3 days". 633 * <p> 634 * This instance is immutable and unaffected by this method call. 635 * 636 * @param yearsToAdd the years to add, positive or negative 637 * @return a {@code Period} based on this period with the specified years added, not null 638 * @throws ArithmeticException if numeric overflow occurs 639 */ plusYears(long yearsToAdd)640 public Period plusYears(long yearsToAdd) { 641 if (yearsToAdd == 0) { 642 return this; 643 } 644 return create(Math.toIntExact(Math.addExact(years, yearsToAdd)), months, days); 645 } 646 647 /** 648 * Returns a copy of this period with the specified months added. 649 * <p> 650 * This adds the amount to the months unit in a copy of this period. 651 * The years and days units are unaffected. 652 * For example, "1 year, 6 months and 3 days" plus 2 months returns "1 year, 8 months and 3 days". 653 * <p> 654 * This instance is immutable and unaffected by this method call. 655 * 656 * @param monthsToAdd the months to add, positive or negative 657 * @return a {@code Period} based on this period with the specified months added, not null 658 * @throws ArithmeticException if numeric overflow occurs 659 */ plusMonths(long monthsToAdd)660 public Period plusMonths(long monthsToAdd) { 661 if (monthsToAdd == 0) { 662 return this; 663 } 664 return create(years, Math.toIntExact(Math.addExact(months, monthsToAdd)), days); 665 } 666 667 /** 668 * Returns a copy of this period with the specified days added. 669 * <p> 670 * This adds the amount to the days unit in a copy of this period. 671 * The years and months units are unaffected. 672 * For example, "1 year, 6 months and 3 days" plus 2 days returns "1 year, 6 months and 5 days". 673 * <p> 674 * This instance is immutable and unaffected by this method call. 675 * 676 * @param daysToAdd the days to add, positive or negative 677 * @return a {@code Period} based on this period with the specified days added, not null 678 * @throws ArithmeticException if numeric overflow occurs 679 */ plusDays(long daysToAdd)680 public Period plusDays(long daysToAdd) { 681 if (daysToAdd == 0) { 682 return this; 683 } 684 return create(years, months, Math.toIntExact(Math.addExact(days, daysToAdd))); 685 } 686 687 //----------------------------------------------------------------------- 688 /** 689 * Returns a copy of this period with the specified period subtracted. 690 * <p> 691 * This operates separately on the years, months and days. 692 * No normalization is performed. 693 * <p> 694 * For example, "1 year, 6 months and 3 days" minus "2 years, 2 months and 2 days" 695 * returns "-1 years, 4 months and 1 day". 696 * <p> 697 * The specified amount is typically an instance of {@code Period}. 698 * Other types are interpreted using {@link Period#from(TemporalAmount)}. 699 * <p> 700 * This instance is immutable and unaffected by this method call. 701 * 702 * @param amountToSubtract the amount to subtract, not null 703 * @return a {@code Period} based on this period with the requested period subtracted, not null 704 * @throws DateTimeException if the specified amount has a non-ISO chronology or 705 * contains an invalid unit 706 * @throws ArithmeticException if numeric overflow occurs 707 */ minus(TemporalAmount amountToSubtract)708 public Period minus(TemporalAmount amountToSubtract) { 709 Period isoAmount = Period.from(amountToSubtract); 710 return create( 711 Math.subtractExact(years, isoAmount.years), 712 Math.subtractExact(months, isoAmount.months), 713 Math.subtractExact(days, isoAmount.days)); 714 } 715 716 /** 717 * Returns a copy of this period with the specified years subtracted. 718 * <p> 719 * This subtracts the amount from the years unit in a copy of this period. 720 * The months and days units are unaffected. 721 * For example, "1 year, 6 months and 3 days" minus 2 years returns "-1 years, 6 months and 3 days". 722 * <p> 723 * This instance is immutable and unaffected by this method call. 724 * 725 * @param yearsToSubtract the years to subtract, positive or negative 726 * @return a {@code Period} based on this period with the specified years subtracted, not null 727 * @throws ArithmeticException if numeric overflow occurs 728 */ minusYears(long yearsToSubtract)729 public Period minusYears(long yearsToSubtract) { 730 return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract)); 731 } 732 733 /** 734 * Returns a copy of this period with the specified months subtracted. 735 * <p> 736 * This subtracts the amount from the months unit in a copy of this period. 737 * The years and days units are unaffected. 738 * For example, "1 year, 6 months and 3 days" minus 2 months returns "1 year, 4 months and 3 days". 739 * <p> 740 * This instance is immutable and unaffected by this method call. 741 * 742 * @param monthsToSubtract the years to subtract, positive or negative 743 * @return a {@code Period} based on this period with the specified months subtracted, not null 744 * @throws ArithmeticException if numeric overflow occurs 745 */ minusMonths(long monthsToSubtract)746 public Period minusMonths(long monthsToSubtract) { 747 return (monthsToSubtract == Long.MIN_VALUE ? plusMonths(Long.MAX_VALUE).plusMonths(1) : plusMonths(-monthsToSubtract)); 748 } 749 750 /** 751 * Returns a copy of this period with the specified days subtracted. 752 * <p> 753 * This subtracts the amount from the days unit in a copy of this period. 754 * The years and months units are unaffected. 755 * For example, "1 year, 6 months and 3 days" minus 2 days returns "1 year, 6 months and 1 day". 756 * <p> 757 * This instance is immutable and unaffected by this method call. 758 * 759 * @param daysToSubtract the months to subtract, positive or negative 760 * @return a {@code Period} based on this period with the specified days subtracted, not null 761 * @throws ArithmeticException if numeric overflow occurs 762 */ minusDays(long daysToSubtract)763 public Period minusDays(long daysToSubtract) { 764 return (daysToSubtract == Long.MIN_VALUE ? plusDays(Long.MAX_VALUE).plusDays(1) : plusDays(-daysToSubtract)); 765 } 766 767 //----------------------------------------------------------------------- 768 /** 769 * Returns a new instance with each element in this period multiplied 770 * by the specified scalar. 771 * <p> 772 * This returns a period with each of the years, months and days units 773 * individually multiplied. 774 * For example, a period of "2 years, -3 months and 4 days" multiplied by 775 * 3 will return "6 years, -9 months and 12 days". 776 * No normalization is performed. 777 * 778 * @param scalar the scalar to multiply by, not null 779 * @return a {@code Period} based on this period with the amounts multiplied by the scalar, not null 780 * @throws ArithmeticException if numeric overflow occurs 781 */ multipliedBy(int scalar)782 public Period multipliedBy(int scalar) { 783 if (this == ZERO || scalar == 1) { 784 return this; 785 } 786 return create( 787 Math.multiplyExact(years, scalar), 788 Math.multiplyExact(months, scalar), 789 Math.multiplyExact(days, scalar)); 790 } 791 792 /** 793 * Returns a new instance with each amount in this period negated. 794 * <p> 795 * This returns a period with each of the years, months and days units 796 * individually negated. 797 * For example, a period of "2 years, -3 months and 4 days" will be 798 * negated to "-2 years, 3 months and -4 days". 799 * No normalization is performed. 800 * 801 * @return a {@code Period} based on this period with the amounts negated, not null 802 * @throws ArithmeticException if numeric overflow occurs, which only happens if 803 * one of the units has the value {@code Long.MIN_VALUE} 804 */ negated()805 public Period negated() { 806 return multipliedBy(-1); 807 } 808 809 //----------------------------------------------------------------------- 810 /** 811 * Returns a copy of this period with the years and months normalized. 812 * <p> 813 * This normalizes the years and months units, leaving the days unit unchanged. 814 * The months unit is adjusted to have an absolute value less than 11, 815 * with the years unit being adjusted to compensate. For example, a period of 816 * "1 Year and 15 months" will be normalized to "2 years and 3 months". 817 * <p> 818 * The sign of the years and months units will be the same after normalization. 819 * For example, a period of "1 year and -25 months" will be normalized to 820 * "-1 year and -1 month". 821 * <p> 822 * This instance is immutable and unaffected by this method call. 823 * 824 * @return a {@code Period} based on this period with excess months normalized to years, not null 825 * @throws ArithmeticException if numeric overflow occurs 826 */ normalized()827 public Period normalized() { 828 long totalMonths = toTotalMonths(); 829 long splitYears = totalMonths / 12; 830 int splitMonths = (int) (totalMonths % 12); // no overflow 831 if (splitYears == years && splitMonths == months) { 832 return this; 833 } 834 return create(Math.toIntExact(splitYears), splitMonths, days); 835 } 836 837 /** 838 * Gets the total number of months in this period. 839 * <p> 840 * This returns the total number of months in the period by multiplying the 841 * number of years by 12 and adding the number of months. 842 * <p> 843 * This instance is immutable and unaffected by this method call. 844 * 845 * @return the total number of months in the period, may be negative 846 */ toTotalMonths()847 public long toTotalMonths() { 848 return years * 12L + months; // no overflow 849 } 850 851 //------------------------------------------------------------------------- 852 /** 853 * Adds this period to the specified temporal object. 854 * <p> 855 * This returns a temporal object of the same observable type as the input 856 * with this period added. 857 * If the temporal has a chronology, it must be the ISO chronology. 858 * <p> 859 * In most cases, it is clearer to reverse the calling pattern by using 860 * {@link Temporal#plus(TemporalAmount)}. 861 * <pre> 862 * // these two lines are equivalent, but the second approach is recommended 863 * dateTime = thisPeriod.addTo(dateTime); 864 * dateTime = dateTime.plus(thisPeriod); 865 * </pre> 866 * <p> 867 * The calculation operates as follows. 868 * First, the chronology of the temporal is checked to ensure it is ISO chronology or null. 869 * Second, if the months are zero, the years are added if non-zero, otherwise 870 * the combination of years and months is added if non-zero. 871 * Finally, any days are added. 872 * <p> 873 * This approach ensures that a partial period can be added to a partial date. 874 * For example, a period of years and/or months can be added to a {@code YearMonth}, 875 * but a period including days cannot. 876 * The approach also adds years and months together when necessary, which ensures 877 * correct behaviour at the end of the month. 878 * <p> 879 * This instance is immutable and unaffected by this method call. 880 * 881 * @param temporal the temporal object to adjust, not null 882 * @return an object of the same type with the adjustment made, not null 883 * @throws DateTimeException if unable to add 884 * @throws ArithmeticException if numeric overflow occurs 885 */ 886 @Override addTo(Temporal temporal)887 public Temporal addTo(Temporal temporal) { 888 validateChrono(temporal); 889 if (months == 0) { 890 if (years != 0) { 891 temporal = temporal.plus(years, YEARS); 892 } 893 } else { 894 long totalMonths = toTotalMonths(); 895 if (totalMonths != 0) { 896 temporal = temporal.plus(totalMonths, MONTHS); 897 } 898 } 899 if (days != 0) { 900 temporal = temporal.plus(days, DAYS); 901 } 902 return temporal; 903 } 904 905 /** 906 * Subtracts this period from the specified temporal object. 907 * <p> 908 * This returns a temporal object of the same observable type as the input 909 * with this period subtracted. 910 * If the temporal has a chronology, it must be the ISO chronology. 911 * <p> 912 * In most cases, it is clearer to reverse the calling pattern by using 913 * {@link Temporal#minus(TemporalAmount)}. 914 * <pre> 915 * // these two lines are equivalent, but the second approach is recommended 916 * dateTime = thisPeriod.subtractFrom(dateTime); 917 * dateTime = dateTime.minus(thisPeriod); 918 * </pre> 919 * <p> 920 * The calculation operates as follows. 921 * First, the chronology of the temporal is checked to ensure it is ISO chronology or null. 922 * Second, if the months are zero, the years are subtracted if non-zero, otherwise 923 * the combination of years and months is subtracted if non-zero. 924 * Finally, any days are subtracted. 925 * <p> 926 * This approach ensures that a partial period can be subtracted from a partial date. 927 * For example, a period of years and/or months can be subtracted from a {@code YearMonth}, 928 * but a period including days cannot. 929 * The approach also subtracts years and months together when necessary, which ensures 930 * correct behaviour at the end of the month. 931 * <p> 932 * This instance is immutable and unaffected by this method call. 933 * 934 * @param temporal the temporal object to adjust, not null 935 * @return an object of the same type with the adjustment made, not null 936 * @throws DateTimeException if unable to subtract 937 * @throws ArithmeticException if numeric overflow occurs 938 */ 939 @Override subtractFrom(Temporal temporal)940 public Temporal subtractFrom(Temporal temporal) { 941 validateChrono(temporal); 942 if (months == 0) { 943 if (years != 0) { 944 temporal = temporal.minus(years, YEARS); 945 } 946 } else { 947 long totalMonths = toTotalMonths(); 948 if (totalMonths != 0) { 949 temporal = temporal.minus(totalMonths, MONTHS); 950 } 951 } 952 if (days != 0) { 953 temporal = temporal.minus(days, DAYS); 954 } 955 return temporal; 956 } 957 958 /** 959 * Validates that the temporal has the correct chronology. 960 */ validateChrono(TemporalAccessor temporal)961 private void validateChrono(TemporalAccessor temporal) { 962 Objects.requireNonNull(temporal, "temporal"); 963 Chronology temporalChrono = temporal.query(TemporalQueries.chronology()); 964 if (temporalChrono != null && IsoChronology.INSTANCE.equals(temporalChrono) == false) { 965 throw new DateTimeException("Chronology mismatch, expected: ISO, actual: " + temporalChrono.getId()); 966 } 967 } 968 969 //----------------------------------------------------------------------- 970 /** 971 * Checks if this period is equal to another period. 972 * <p> 973 * The comparison is based on the type {@code Period} and each of the three amounts. 974 * To be equal, the years, months and days units must be individually equal. 975 * Note that this means that a period of "15 Months" is not equal to a period 976 * of "1 Year and 3 Months". 977 * 978 * @param obj the object to check, null returns false 979 * @return true if this is equal to the other period 980 */ 981 @Override equals(Object obj)982 public boolean equals(Object obj) { 983 if (this == obj) { 984 return true; 985 } 986 if (obj instanceof Period) { 987 Period other = (Period) obj; 988 return years == other.years && 989 months == other.months && 990 days == other.days; 991 } 992 return false; 993 } 994 995 /** 996 * A hash code for this period. 997 * 998 * @return a suitable hash code 999 */ 1000 @Override hashCode()1001 public int hashCode() { 1002 return years + Integer.rotateLeft(months, 8) + Integer.rotateLeft(days, 16); 1003 } 1004 1005 //----------------------------------------------------------------------- 1006 /** 1007 * Outputs this period as a {@code String}, such as {@code P6Y3M1D}. 1008 * <p> 1009 * The output will be in the ISO-8601 period format. 1010 * A zero period will be represented as zero days, 'P0D'. 1011 * 1012 * @return a string representation of this period, not null 1013 */ 1014 @Override toString()1015 public String toString() { 1016 if (this == ZERO) { 1017 return "P0D"; 1018 } else { 1019 StringBuilder buf = new StringBuilder(); 1020 buf.append('P'); 1021 if (years != 0) { 1022 buf.append(years).append('Y'); 1023 } 1024 if (months != 0) { 1025 buf.append(months).append('M'); 1026 } 1027 if (days != 0) { 1028 buf.append(days).append('D'); 1029 } 1030 return buf.toString(); 1031 } 1032 } 1033 1034 //----------------------------------------------------------------------- 1035 /** 1036 * Writes the object using a 1037 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>. 1038 * @serialData 1039 * <pre> 1040 * out.writeByte(14); // identifies a Period 1041 * out.writeInt(years); 1042 * out.writeInt(months); 1043 * out.writeInt(days); 1044 * </pre> 1045 * 1046 * @return the instance of {@code Ser}, not null 1047 */ writeReplace()1048 private Object writeReplace() { 1049 return new Ser(Ser.PERIOD_TYPE, this); 1050 } 1051 1052 /** 1053 * Defend against malicious streams. 1054 * 1055 * @param s the stream to read 1056 * @throws java.io.InvalidObjectException always 1057 */ readObject(ObjectInputStream s)1058 private void readObject(ObjectInputStream s) throws InvalidObjectException { 1059 throw new InvalidObjectException("Deserialization via serialization delegate"); 1060 } 1061 writeExternal(DataOutput out)1062 void writeExternal(DataOutput out) throws IOException { 1063 out.writeInt(years); 1064 out.writeInt(months); 1065 out.writeInt(days); 1066 } 1067 readExternal(DataInput in)1068 static Period readExternal(DataInput in) throws IOException { 1069 int years = in.readInt(); 1070 int months = in.readInt(); 1071 int days = in.readInt(); 1072 return Period.of(years, months, days); 1073 } 1074 1075 } 1076