/* * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file: * * Copyright (c) 2008-2012, Stephen Colebourne & Michael Nascimento Santos * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * * Neither the name of JSR-310 nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package java.time; import static java.time.temporal.ChronoUnit.DAYS; import static java.time.temporal.ChronoUnit.MONTHS; import static java.time.temporal.ChronoUnit.YEARS; import java.io.DataInput; import java.io.DataOutput; import java.io.IOException; import java.io.InvalidObjectException; import java.io.ObjectInputStream; import java.io.Serializable; import java.time.chrono.ChronoLocalDate; import java.time.chrono.ChronoPeriod; import java.time.chrono.Chronology; import java.time.chrono.IsoChronology; import java.time.format.DateTimeParseException; import java.time.temporal.ChronoUnit; import java.time.temporal.Temporal; import java.time.temporal.TemporalAccessor; import java.time.temporal.TemporalAmount; import java.time.temporal.TemporalQueries; import java.time.temporal.TemporalUnit; import java.time.temporal.UnsupportedTemporalTypeException; import java.util.Arrays; import java.util.Collections; import java.util.List; import java.util.Objects; import java.util.regex.Matcher; import java.util.regex.Pattern; // Android-changed: removed ValueBased paragraph. /** * A date-based amount of time in the ISO-8601 calendar system, * such as '2 years, 3 months and 4 days'. *

* This class models a quantity or amount of time in terms of years, months and days. * See {@link Duration} for the time-based equivalent to this class. *

* Durations and periods differ in their treatment of daylight savings time * when added to {@link ZonedDateTime}. A {@code Duration} will add an exact * number of seconds, thus a duration of one day is always exactly 24 hours. * By contrast, a {@code Period} will add a conceptual day, trying to maintain * the local time. *

* For example, consider adding a period of one day and a duration of one day to * 18:00 on the evening before a daylight savings gap. The {@code Period} will add * the conceptual day and result in a {@code ZonedDateTime} at 18:00 the following day. * By contrast, the {@code Duration} will add exactly 24 hours, resulting in a * {@code ZonedDateTime} at 19:00 the following day (assuming a one hour DST gap). *

* The supported units of a period are {@link ChronoUnit#YEARS YEARS}, * {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. * All three fields are always present, but may be set to zero. *

* The ISO-8601 calendar system is the modern civil calendar system used today * in most of the world. It is equivalent to the proleptic Gregorian calendar * system, in which today's rules for leap years are applied for all time. *

* The period is modeled as a directed amount of time, meaning that individual parts of the * period may be negative. * * @implSpec * This class is immutable and thread-safe. * * @since 1.8 */ public final class Period implements ChronoPeriod, Serializable { /** * A constant for a period of zero. */ public static final Period ZERO = new Period(0, 0, 0); /** * Serialization version. */ private static final long serialVersionUID = -3587258372562876L; /** * The pattern for parsing. */ private static final Pattern PATTERN = Pattern.compile("([-+]?)P(?:([-+]?[0-9]+)Y)?(?:([-+]?[0-9]+)M)?(?:([-+]?[0-9]+)W)?(?:([-+]?[0-9]+)D)?", Pattern.CASE_INSENSITIVE); /** * The set of supported units. */ private static final List SUPPORTED_UNITS = Collections.unmodifiableList(Arrays.asList(YEARS, MONTHS, DAYS)); /** * The number of years. */ private final int years; /** * The number of months. */ private final int months; /** * The number of days. */ private final int days; //----------------------------------------------------------------------- /** * Obtains a {@code Period} representing a number of years. *

* The resulting period will have the specified years. * The months and days units will be zero. * * @param years the number of years, positive or negative * @return the period of years, not null */ public static Period ofYears(int years) { return create(years, 0, 0); } /** * Obtains a {@code Period} representing a number of months. *

* The resulting period will have the specified months. * The years and days units will be zero. * * @param months the number of months, positive or negative * @return the period of months, not null */ public static Period ofMonths(int months) { return create(0, months, 0); } /** * Obtains a {@code Period} representing a number of weeks. *

* The resulting period will be day-based, with the amount of days * equal to the number of weeks multiplied by 7. * The years and months units will be zero. * * @param weeks the number of weeks, positive or negative * @return the period, with the input weeks converted to days, not null */ public static Period ofWeeks(int weeks) { return create(0, 0, Math.multiplyExact(weeks, 7)); } /** * Obtains a {@code Period} representing a number of days. *

* The resulting period will have the specified days. * The years and months units will be zero. * * @param days the number of days, positive or negative * @return the period of days, not null */ public static Period ofDays(int days) { return create(0, 0, days); } //----------------------------------------------------------------------- /** * Obtains a {@code Period} representing a number of years, months and days. *

* This creates an instance based on years, months and days. * * @param years the amount of years, may be negative * @param months the amount of months, may be negative * @param days the amount of days, may be negative * @return the period of years, months and days, not null */ public static Period of(int years, int months, int days) { return create(years, months, days); } //----------------------------------------------------------------------- /** * Obtains an instance of {@code Period} from a temporal amount. *

* This obtains a period based on the specified amount. * A {@code TemporalAmount} represents an amount of time, which may be * date-based or time-based, which this factory extracts to a {@code Period}. *

* The conversion loops around the set of units from the amount and uses * the {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} * and {@link ChronoUnit#DAYS DAYS} units to create a period. * If any other units are found then an exception is thrown. *

* If the amount is a {@code ChronoPeriod} then it must use the ISO chronology. * * @param amount the temporal amount to convert, not null * @return the equivalent period, not null * @throws DateTimeException if unable to convert to a {@code Period} * @throws ArithmeticException if the amount of years, months or days exceeds an int */ public static Period from(TemporalAmount amount) { if (amount instanceof Period) { return (Period) amount; } if (amount instanceof ChronoPeriod) { if (IsoChronology.INSTANCE.equals(((ChronoPeriod) amount).getChronology()) == false) { throw new DateTimeException("Period requires ISO chronology: " + amount); } } Objects.requireNonNull(amount, "amount"); int years = 0; int months = 0; int days = 0; for (TemporalUnit unit : amount.getUnits()) { long unitAmount = amount.get(unit); if (unit == ChronoUnit.YEARS) { years = Math.toIntExact(unitAmount); } else if (unit == ChronoUnit.MONTHS) { months = Math.toIntExact(unitAmount); } else if (unit == ChronoUnit.DAYS) { days = Math.toIntExact(unitAmount); } else { throw new DateTimeException("Unit must be Years, Months or Days, but was " + unit); } } return create(years, months, days); } //----------------------------------------------------------------------- /** * Obtains a {@code Period} from a text string such as {@code PnYnMnD}. *

* This will parse the string produced by {@code toString()} which is * based on the ISO-8601 period formats {@code PnYnMnD} and {@code PnW}. *

* The string starts with an optional sign, denoted by the ASCII negative * or positive symbol. If negative, the whole period is negated. * The ASCII letter "P" is next in upper or lower case. * There are then four sections, each consisting of a number and a suffix. * At least one of the four sections must be present. * The sections have suffixes in ASCII of "Y", "M", "W" and "D" for * years, months, weeks and days, accepted in upper or lower case. * The suffixes must occur in order. * The number part of each section must consist of ASCII digits. * The number may be prefixed by the ASCII negative or positive symbol. * The number must parse to an {@code int}. *

* The leading plus/minus sign, and negative values for other units are * not part of the ISO-8601 standard. In addition, ISO-8601 does not * permit mixing between the {@code PnYnMnD} and {@code PnW} formats. * Any week-based input is multiplied by 7 and treated as a number of days. *

* For example, the following are valid inputs: *

     *   "P2Y"             -- Period.ofYears(2)
     *   "P3M"             -- Period.ofMonths(3)
     *   "P4W"             -- Period.ofWeeks(4)
     *   "P5D"             -- Period.ofDays(5)
     *   "P1Y2M3D"         -- Period.of(1, 2, 3)
     *   "P1Y2M3W4D"       -- Period.of(1, 2, 25)
     *   "P-1Y2M"          -- Period.of(-1, 2, 0)
     *   "-P1Y2M"          -- Period.of(-1, -2, 0)
     * 
* * @param text the text to parse, not null * @return the parsed period, not null * @throws DateTimeParseException if the text cannot be parsed to a period */ public static Period parse(CharSequence text) { Objects.requireNonNull(text, "text"); Matcher matcher = PATTERN.matcher(text); if (matcher.matches()) { int negate = ("-".equals(matcher.group(1)) ? -1 : 1); String yearMatch = matcher.group(2); String monthMatch = matcher.group(3); String weekMatch = matcher.group(4); String dayMatch = matcher.group(5); if (yearMatch != null || monthMatch != null || dayMatch != null || weekMatch != null) { try { int years = parseNumber(text, yearMatch, negate); int months = parseNumber(text, monthMatch, negate); int weeks = parseNumber(text, weekMatch, negate); int days = parseNumber(text, dayMatch, negate); days = Math.addExact(days, Math.multiplyExact(weeks, 7)); return create(years, months, days); } catch (NumberFormatException ex) { throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex); } } } throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0); } private static int parseNumber(CharSequence text, String str, int negate) { if (str == null) { return 0; } int val = Integer.parseInt(str); try { return Math.multiplyExact(val, negate); } catch (ArithmeticException ex) { throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex); } } //----------------------------------------------------------------------- /** * Obtains a {@code Period} consisting of the number of years, months, * and days between two dates. *

* The start date is included, but the end date is not. * The period is calculated by removing complete months, then calculating * the remaining number of days, adjusting to ensure that both have the same sign. * The number of months is then split into years and months based on a 12 month year. * A month is considered if the end day-of-month is greater than or equal to the start day-of-month. * For example, from {@code 2010-01-15} to {@code 2011-03-18} is one year, two months and three days. *

* The result of this method can be a negative period if the end is before the start. * The negative sign will be the same in each of year, month and day. * * @param startDateInclusive the start date, inclusive, not null * @param endDateExclusive the end date, exclusive, not null * @return the period between this date and the end date, not null * @see ChronoLocalDate#until(ChronoLocalDate) */ public static Period between(LocalDate startDateInclusive, LocalDate endDateExclusive) { return startDateInclusive.until(endDateExclusive); } //----------------------------------------------------------------------- /** * Creates an instance. * * @param years the amount * @param months the amount * @param days the amount */ private static Period create(int years, int months, int days) { if ((years | months | days) == 0) { return ZERO; } return new Period(years, months, days); } /** * Constructor. * * @param years the amount * @param months the amount * @param days the amount */ private Period(int years, int months, int days) { this.years = years; this.months = months; this.days = days; } //----------------------------------------------------------------------- /** * Gets the value of the requested unit. *

* This returns a value for each of the three supported units, * {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} and * {@link ChronoUnit#DAYS DAYS}. * All other units throw an exception. * * @param unit the {@code TemporalUnit} for which to return the value * @return the long value of the unit * @throws DateTimeException if the unit is not supported * @throws UnsupportedTemporalTypeException if the unit is not supported */ @Override public long get(TemporalUnit unit) { if (unit == ChronoUnit.YEARS) { return getYears(); } else if (unit == ChronoUnit.MONTHS) { return getMonths(); } else if (unit == ChronoUnit.DAYS) { return getDays(); } else { throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); } } /** * Gets the set of units supported by this period. *

* The supported units are {@link ChronoUnit#YEARS YEARS}, * {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. * They are returned in the order years, months, days. *

* This set can be used in conjunction with {@link #get(TemporalUnit)} * to access the entire state of the period. * * @return a list containing the years, months and days units, not null */ @Override public List getUnits() { return SUPPORTED_UNITS; } /** * Gets the chronology of this period, which is the ISO calendar system. *

* The {@code Chronology} represents the calendar system in use. * The ISO-8601 calendar system is the modern civil calendar system used today * in most of the world. It is equivalent to the proleptic Gregorian calendar * system, in which today's rules for leap years are applied for all time. * * @return the ISO chronology, not null */ @Override public IsoChronology getChronology() { return IsoChronology.INSTANCE; } //----------------------------------------------------------------------- /** * Checks if all three units of this period are zero. *

* A zero period has the value zero for the years, months and days units. * * @return true if this period is zero-length */ public boolean isZero() { return (this == ZERO); } /** * Checks if any of the three units of this period are negative. *

* This checks whether the years, months or days units are less than zero. * * @return true if any unit of this period is negative */ public boolean isNegative() { return years < 0 || months < 0 || days < 0; } //----------------------------------------------------------------------- /** * Gets the amount of years of this period. *

* This returns the years unit. *

* The months unit is not automatically normalized with the years unit. * This means that a period of "15 months" is different to a period * of "1 year and 3 months". * * @return the amount of years of this period, may be negative */ public int getYears() { return years; } /** * Gets the amount of months of this period. *

* This returns the months unit. *

* The months unit is not automatically normalized with the years unit. * This means that a period of "15 months" is different to a period * of "1 year and 3 months". * * @return the amount of months of this period, may be negative */ public int getMonths() { return months; } /** * Gets the amount of days of this period. *

* This returns the days unit. * * @return the amount of days of this period, may be negative */ public int getDays() { return days; } //----------------------------------------------------------------------- /** * Returns a copy of this period with the specified amount of years. *

* This sets the amount of the years unit in a copy of this period. * The months and days units are unaffected. *

* The months unit is not automatically normalized with the years unit. * This means that a period of "15 months" is different to a period * of "1 year and 3 months". *

* This instance is immutable and unaffected by this method call. * * @param years the years to represent, may be negative * @return a {@code Period} based on this period with the requested years, not null */ public Period withYears(int years) { if (years == this.years) { return this; } return create(years, months, days); } /** * Returns a copy of this period with the specified amount of months. *

* This sets the amount of the months unit in a copy of this period. * The years and days units are unaffected. *

* The months unit is not automatically normalized with the years unit. * This means that a period of "15 months" is different to a period * of "1 year and 3 months". *

* This instance is immutable and unaffected by this method call. * * @param months the months to represent, may be negative * @return a {@code Period} based on this period with the requested months, not null */ public Period withMonths(int months) { if (months == this.months) { return this; } return create(years, months, days); } /** * Returns a copy of this period with the specified amount of days. *

* This sets the amount of the days unit in a copy of this period. * The years and months units are unaffected. *

* This instance is immutable and unaffected by this method call. * * @param days the days to represent, may be negative * @return a {@code Period} based on this period with the requested days, not null */ public Period withDays(int days) { if (days == this.days) { return this; } return create(years, months, days); } //----------------------------------------------------------------------- /** * Returns a copy of this period with the specified period added. *

* This operates separately on the years, months and days. * No normalization is performed. *

* For example, "1 year, 6 months and 3 days" plus "2 years, 2 months and 2 days" * returns "3 years, 8 months and 5 days". *

* The specified amount is typically an instance of {@code Period}. * Other types are interpreted using {@link Period#from(TemporalAmount)}. *

* This instance is immutable and unaffected by this method call. * * @param amountToAdd the amount to add, not null * @return a {@code Period} based on this period with the requested period added, not null * @throws DateTimeException if the specified amount has a non-ISO chronology or * contains an invalid unit * @throws ArithmeticException if numeric overflow occurs */ public Period plus(TemporalAmount amountToAdd) { Period isoAmount = Period.from(amountToAdd); return create( Math.addExact(years, isoAmount.years), Math.addExact(months, isoAmount.months), Math.addExact(days, isoAmount.days)); } /** * Returns a copy of this period with the specified years added. *

* This adds the amount to the years unit in a copy of this period. * The months and days units are unaffected. * For example, "1 year, 6 months and 3 days" plus 2 years returns "3 years, 6 months and 3 days". *

* This instance is immutable and unaffected by this method call. * * @param yearsToAdd the years to add, positive or negative * @return a {@code Period} based on this period with the specified years added, not null * @throws ArithmeticException if numeric overflow occurs */ public Period plusYears(long yearsToAdd) { if (yearsToAdd == 0) { return this; } return create(Math.toIntExact(Math.addExact(years, yearsToAdd)), months, days); } /** * Returns a copy of this period with the specified months added. *

* This adds the amount to the months unit in a copy of this period. * The years and days units are unaffected. * For example, "1 year, 6 months and 3 days" plus 2 months returns "1 year, 8 months and 3 days". *

* This instance is immutable and unaffected by this method call. * * @param monthsToAdd the months to add, positive or negative * @return a {@code Period} based on this period with the specified months added, not null * @throws ArithmeticException if numeric overflow occurs */ public Period plusMonths(long monthsToAdd) { if (monthsToAdd == 0) { return this; } return create(years, Math.toIntExact(Math.addExact(months, monthsToAdd)), days); } /** * Returns a copy of this period with the specified days added. *

* This adds the amount to the days unit in a copy of this period. * The years and months units are unaffected. * For example, "1 year, 6 months and 3 days" plus 2 days returns "1 year, 6 months and 5 days". *

* This instance is immutable and unaffected by this method call. * * @param daysToAdd the days to add, positive or negative * @return a {@code Period} based on this period with the specified days added, not null * @throws ArithmeticException if numeric overflow occurs */ public Period plusDays(long daysToAdd) { if (daysToAdd == 0) { return this; } return create(years, months, Math.toIntExact(Math.addExact(days, daysToAdd))); } //----------------------------------------------------------------------- /** * Returns a copy of this period with the specified period subtracted. *

* This operates separately on the years, months and days. * No normalization is performed. *

* For example, "1 year, 6 months and 3 days" minus "2 years, 2 months and 2 days" * returns "-1 years, 4 months and 1 day". *

* The specified amount is typically an instance of {@code Period}. * Other types are interpreted using {@link Period#from(TemporalAmount)}. *

* This instance is immutable and unaffected by this method call. * * @param amountToSubtract the amount to subtract, not null * @return a {@code Period} based on this period with the requested period subtracted, not null * @throws DateTimeException if the specified amount has a non-ISO chronology or * contains an invalid unit * @throws ArithmeticException if numeric overflow occurs */ public Period minus(TemporalAmount amountToSubtract) { Period isoAmount = Period.from(amountToSubtract); return create( Math.subtractExact(years, isoAmount.years), Math.subtractExact(months, isoAmount.months), Math.subtractExact(days, isoAmount.days)); } /** * Returns a copy of this period with the specified years subtracted. *

* This subtracts the amount from the years unit in a copy of this period. * The months and days units are unaffected. * For example, "1 year, 6 months and 3 days" minus 2 years returns "-1 years, 6 months and 3 days". *

* This instance is immutable and unaffected by this method call. * * @param yearsToSubtract the years to subtract, positive or negative * @return a {@code Period} based on this period with the specified years subtracted, not null * @throws ArithmeticException if numeric overflow occurs */ public Period minusYears(long yearsToSubtract) { return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract)); } /** * Returns a copy of this period with the specified months subtracted. *

* This subtracts the amount from the months unit in a copy of this period. * The years and days units are unaffected. * For example, "1 year, 6 months and 3 days" minus 2 months returns "1 year, 4 months and 3 days". *

* This instance is immutable and unaffected by this method call. * * @param monthsToSubtract the years to subtract, positive or negative * @return a {@code Period} based on this period with the specified months subtracted, not null * @throws ArithmeticException if numeric overflow occurs */ public Period minusMonths(long monthsToSubtract) { return (monthsToSubtract == Long.MIN_VALUE ? plusMonths(Long.MAX_VALUE).plusMonths(1) : plusMonths(-monthsToSubtract)); } /** * Returns a copy of this period with the specified days subtracted. *

* This subtracts the amount from the days unit in a copy of this period. * The years and months units are unaffected. * For example, "1 year, 6 months and 3 days" minus 2 days returns "1 year, 6 months and 1 day". *

* This instance is immutable and unaffected by this method call. * * @param daysToSubtract the months to subtract, positive or negative * @return a {@code Period} based on this period with the specified days subtracted, not null * @throws ArithmeticException if numeric overflow occurs */ public Period minusDays(long daysToSubtract) { return (daysToSubtract == Long.MIN_VALUE ? plusDays(Long.MAX_VALUE).plusDays(1) : plusDays(-daysToSubtract)); } //----------------------------------------------------------------------- /** * Returns a new instance with each element in this period multiplied * by the specified scalar. *

* This returns a period with each of the years, months and days units * individually multiplied. * For example, a period of "2 years, -3 months and 4 days" multiplied by * 3 will return "6 years, -9 months and 12 days". * No normalization is performed. * * @param scalar the scalar to multiply by, not null * @return a {@code Period} based on this period with the amounts multiplied by the scalar, not null * @throws ArithmeticException if numeric overflow occurs */ public Period multipliedBy(int scalar) { if (this == ZERO || scalar == 1) { return this; } return create( Math.multiplyExact(years, scalar), Math.multiplyExact(months, scalar), Math.multiplyExact(days, scalar)); } /** * Returns a new instance with each amount in this period negated. *

* This returns a period with each of the years, months and days units * individually negated. * For example, a period of "2 years, -3 months and 4 days" will be * negated to "-2 years, 3 months and -4 days". * No normalization is performed. * * @return a {@code Period} based on this period with the amounts negated, not null * @throws ArithmeticException if numeric overflow occurs, which only happens if * one of the units has the value {@code Long.MIN_VALUE} */ public Period negated() { return multipliedBy(-1); } //----------------------------------------------------------------------- /** * Returns a copy of this period with the years and months normalized. *

* This normalizes the years and months units, leaving the days unit unchanged. * The months unit is adjusted to have an absolute value less than 11, * with the years unit being adjusted to compensate. For example, a period of * "1 Year and 15 months" will be normalized to "2 years and 3 months". *

* The sign of the years and months units will be the same after normalization. * For example, a period of "1 year and -25 months" will be normalized to * "-1 year and -1 month". *

* This instance is immutable and unaffected by this method call. * * @return a {@code Period} based on this period with excess months normalized to years, not null * @throws ArithmeticException if numeric overflow occurs */ public Period normalized() { long totalMonths = toTotalMonths(); long splitYears = totalMonths / 12; int splitMonths = (int) (totalMonths % 12); // no overflow if (splitYears == years && splitMonths == months) { return this; } return create(Math.toIntExact(splitYears), splitMonths, days); } /** * Gets the total number of months in this period. *

* This returns the total number of months in the period by multiplying the * number of years by 12 and adding the number of months. *

* This instance is immutable and unaffected by this method call. * * @return the total number of months in the period, may be negative */ public long toTotalMonths() { return years * 12L + months; // no overflow } //------------------------------------------------------------------------- /** * Adds this period to the specified temporal object. *

* This returns a temporal object of the same observable type as the input * with this period added. * If the temporal has a chronology, it must be the ISO chronology. *

* In most cases, it is clearer to reverse the calling pattern by using * {@link Temporal#plus(TemporalAmount)}. *

     *   // these two lines are equivalent, but the second approach is recommended
     *   dateTime = thisPeriod.addTo(dateTime);
     *   dateTime = dateTime.plus(thisPeriod);
     * 
*

* The calculation operates as follows. * First, the chronology of the temporal is checked to ensure it is ISO chronology or null. * Second, if the months are zero, the years are added if non-zero, otherwise * the combination of years and months is added if non-zero. * Finally, any days are added. *

* This approach ensures that a partial period can be added to a partial date. * For example, a period of years and/or months can be added to a {@code YearMonth}, * but a period including days cannot. * The approach also adds years and months together when necessary, which ensures * correct behaviour at the end of the month. *

* This instance is immutable and unaffected by this method call. * * @param temporal the temporal object to adjust, not null * @return an object of the same type with the adjustment made, not null * @throws DateTimeException if unable to add * @throws ArithmeticException if numeric overflow occurs */ @Override public Temporal addTo(Temporal temporal) { validateChrono(temporal); if (months == 0) { if (years != 0) { temporal = temporal.plus(years, YEARS); } } else { long totalMonths = toTotalMonths(); if (totalMonths != 0) { temporal = temporal.plus(totalMonths, MONTHS); } } if (days != 0) { temporal = temporal.plus(days, DAYS); } return temporal; } /** * Subtracts this period from the specified temporal object. *

* This returns a temporal object of the same observable type as the input * with this period subtracted. * If the temporal has a chronology, it must be the ISO chronology. *

* In most cases, it is clearer to reverse the calling pattern by using * {@link Temporal#minus(TemporalAmount)}. *

     *   // these two lines are equivalent, but the second approach is recommended
     *   dateTime = thisPeriod.subtractFrom(dateTime);
     *   dateTime = dateTime.minus(thisPeriod);
     * 
*

* The calculation operates as follows. * First, the chronology of the temporal is checked to ensure it is ISO chronology or null. * Second, if the months are zero, the years are subtracted if non-zero, otherwise * the combination of years and months is subtracted if non-zero. * Finally, any days are subtracted. *

* This approach ensures that a partial period can be subtracted from a partial date. * For example, a period of years and/or months can be subtracted from a {@code YearMonth}, * but a period including days cannot. * The approach also subtracts years and months together when necessary, which ensures * correct behaviour at the end of the month. *

* This instance is immutable and unaffected by this method call. * * @param temporal the temporal object to adjust, not null * @return an object of the same type with the adjustment made, not null * @throws DateTimeException if unable to subtract * @throws ArithmeticException if numeric overflow occurs */ @Override public Temporal subtractFrom(Temporal temporal) { validateChrono(temporal); if (months == 0) { if (years != 0) { temporal = temporal.minus(years, YEARS); } } else { long totalMonths = toTotalMonths(); if (totalMonths != 0) { temporal = temporal.minus(totalMonths, MONTHS); } } if (days != 0) { temporal = temporal.minus(days, DAYS); } return temporal; } /** * Validates that the temporal has the correct chronology. */ private void validateChrono(TemporalAccessor temporal) { Objects.requireNonNull(temporal, "temporal"); Chronology temporalChrono = temporal.query(TemporalQueries.chronology()); if (temporalChrono != null && IsoChronology.INSTANCE.equals(temporalChrono) == false) { throw new DateTimeException("Chronology mismatch, expected: ISO, actual: " + temporalChrono.getId()); } } //----------------------------------------------------------------------- /** * Checks if this period is equal to another period. *

* The comparison is based on the type {@code Period} and each of the three amounts. * To be equal, the years, months and days units must be individually equal. * Note that this means that a period of "15 Months" is not equal to a period * of "1 Year and 3 Months". * * @param obj the object to check, null returns false * @return true if this is equal to the other period */ @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj instanceof Period) { Period other = (Period) obj; return years == other.years && months == other.months && days == other.days; } return false; } /** * A hash code for this period. * * @return a suitable hash code */ @Override public int hashCode() { return years + Integer.rotateLeft(months, 8) + Integer.rotateLeft(days, 16); } //----------------------------------------------------------------------- /** * Outputs this period as a {@code String}, such as {@code P6Y3M1D}. *

* The output will be in the ISO-8601 period format. * A zero period will be represented as zero days, 'P0D'. * * @return a string representation of this period, not null */ @Override public String toString() { if (this == ZERO) { return "P0D"; } else { StringBuilder buf = new StringBuilder(); buf.append('P'); if (years != 0) { buf.append(years).append('Y'); } if (months != 0) { buf.append(months).append('M'); } if (days != 0) { buf.append(days).append('D'); } return buf.toString(); } } //----------------------------------------------------------------------- /** * Writes the object using a * dedicated serialized form. * @serialData *

     *  out.writeByte(14);  // identifies a Period
     *  out.writeInt(years);
     *  out.writeInt(months);
     *  out.writeInt(days);
     * 
* * @return the instance of {@code Ser}, not null */ private Object writeReplace() { return new Ser(Ser.PERIOD_TYPE, this); } /** * Defend against malicious streams. * * @param s the stream to read * @throws java.io.InvalidObjectException always */ private void readObject(ObjectInputStream s) throws InvalidObjectException { throw new InvalidObjectException("Deserialization via serialization delegate"); } void writeExternal(DataOutput out) throws IOException { out.writeInt(years); out.writeInt(months); out.writeInt(days); } static Period readExternal(DataInput in) throws IOException { int years = in.readInt(); int months = in.readInt(); int days = in.readInt(); return Period.of(years, months, days); } }