| /* |
| * 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) 2007-2012, 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.ChronoField.ERA; |
| import static java.time.temporal.ChronoField.MONTH_OF_YEAR; |
| import static java.time.temporal.ChronoField.PROLEPTIC_MONTH; |
| import static java.time.temporal.ChronoField.YEAR; |
| import static java.time.temporal.ChronoField.YEAR_OF_ERA; |
| import static java.time.temporal.ChronoUnit.CENTURIES; |
| import static java.time.temporal.ChronoUnit.DECADES; |
| import static java.time.temporal.ChronoUnit.ERAS; |
| import static java.time.temporal.ChronoUnit.MILLENNIA; |
| 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.Chronology; |
| import java.time.chrono.IsoChronology; |
| import java.time.format.DateTimeFormatter; |
| import java.time.format.DateTimeFormatterBuilder; |
| import java.time.format.DateTimeParseException; |
| import java.time.format.SignStyle; |
| import java.time.temporal.ChronoField; |
| import java.time.temporal.ChronoUnit; |
| import java.time.temporal.Temporal; |
| import java.time.temporal.TemporalAccessor; |
| import java.time.temporal.TemporalAdjuster; |
| import java.time.temporal.TemporalAmount; |
| import java.time.temporal.TemporalField; |
| import java.time.temporal.TemporalQueries; |
| import java.time.temporal.TemporalQuery; |
| import java.time.temporal.TemporalUnit; |
| import java.time.temporal.UnsupportedTemporalTypeException; |
| import java.time.temporal.ValueRange; |
| import java.util.Objects; |
| |
| // Android-changed: removed ValueBased paragraph. |
| /** |
| * A year-month in the ISO-8601 calendar system, such as {@code 2007-12}. |
| * <p> |
| * {@code YearMonth} is an immutable date-time object that represents the combination |
| * of a year and month. Any field that can be derived from a year and month, such as |
| * quarter-of-year, can be obtained. |
| * <p> |
| * This class does not store or represent a day, time or time-zone. |
| * For example, the value "October 2007" can be stored in a {@code YearMonth}. |
| * <p> |
| * 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. |
| * For most applications written today, the ISO-8601 rules are entirely suitable. |
| * However, any application that makes use of historical dates, and requires them |
| * to be accurate will find the ISO-8601 approach unsuitable. |
| * |
| * @implSpec |
| * This class is immutable and thread-safe. |
| * |
| * @since 1.8 |
| */ |
| public final class YearMonth |
| implements Temporal, TemporalAdjuster, Comparable<YearMonth>, Serializable { |
| |
| /** |
| * Serialization version. |
| */ |
| private static final long serialVersionUID = 4183400860270640070L; |
| /** |
| * Parser. |
| */ |
| private static final DateTimeFormatter PARSER = new DateTimeFormatterBuilder() |
| .appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD) |
| .appendLiteral('-') |
| .appendValue(MONTH_OF_YEAR, 2) |
| .toFormatter(); |
| |
| /** |
| * The year. |
| */ |
| private final int year; |
| /** |
| * The month-of-year, not null. |
| */ |
| private final int month; |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Obtains the current year-month from the system clock in the default time-zone. |
| * <p> |
| * This will query the {@link Clock#systemDefaultZone() system clock} in the default |
| * time-zone to obtain the current year-month. |
| * <p> |
| * Using this method will prevent the ability to use an alternate clock for testing |
| * because the clock is hard-coded. |
| * |
| * @return the current year-month using the system clock and default time-zone, not null |
| */ |
| public static YearMonth now() { |
| return now(Clock.systemDefaultZone()); |
| } |
| |
| /** |
| * Obtains the current year-month from the system clock in the specified time-zone. |
| * <p> |
| * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current year-month. |
| * Specifying the time-zone avoids dependence on the default time-zone. |
| * <p> |
| * Using this method will prevent the ability to use an alternate clock for testing |
| * because the clock is hard-coded. |
| * |
| * @param zone the zone ID to use, not null |
| * @return the current year-month using the system clock, not null |
| */ |
| public static YearMonth now(ZoneId zone) { |
| return now(Clock.system(zone)); |
| } |
| |
| /** |
| * Obtains the current year-month from the specified clock. |
| * <p> |
| * This will query the specified clock to obtain the current year-month. |
| * Using this method allows the use of an alternate clock for testing. |
| * The alternate clock may be introduced using {@link Clock dependency injection}. |
| * |
| * @param clock the clock to use, not null |
| * @return the current year-month, not null |
| */ |
| public static YearMonth now(Clock clock) { |
| final LocalDate now = LocalDate.now(clock); // called once |
| return YearMonth.of(now.getYear(), now.getMonth()); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Obtains an instance of {@code YearMonth} from a year and month. |
| * |
| * @param year the year to represent, from MIN_YEAR to MAX_YEAR |
| * @param month the month-of-year to represent, not null |
| * @return the year-month, not null |
| * @throws DateTimeException if the year value is invalid |
| */ |
| public static YearMonth of(int year, Month month) { |
| Objects.requireNonNull(month, "month"); |
| return of(year, month.getValue()); |
| } |
| |
| /** |
| * Obtains an instance of {@code YearMonth} from a year and month. |
| * |
| * @param year the year to represent, from MIN_YEAR to MAX_YEAR |
| * @param month the month-of-year to represent, from 1 (January) to 12 (December) |
| * @return the year-month, not null |
| * @throws DateTimeException if either field value is invalid |
| */ |
| public static YearMonth of(int year, int month) { |
| YEAR.checkValidValue(year); |
| MONTH_OF_YEAR.checkValidValue(month); |
| return new YearMonth(year, month); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Obtains an instance of {@code YearMonth} from a temporal object. |
| * <p> |
| * This obtains a year-month based on the specified temporal. |
| * A {@code TemporalAccessor} represents an arbitrary set of date and time information, |
| * which this factory converts to an instance of {@code YearMonth}. |
| * <p> |
| * The conversion extracts the {@link ChronoField#YEAR YEAR} and |
| * {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} fields. |
| * The extraction is only permitted if the temporal object has an ISO |
| * chronology, or can be converted to a {@code LocalDate}. |
| * <p> |
| * This method matches the signature of the functional interface {@link TemporalQuery} |
| * allowing it to be used as a query via method reference, {@code YearMonth::from}. |
| * |
| * @param temporal the temporal object to convert, not null |
| * @return the year-month, not null |
| * @throws DateTimeException if unable to convert to a {@code YearMonth} |
| */ |
| public static YearMonth from(TemporalAccessor temporal) { |
| if (temporal instanceof YearMonth) { |
| return (YearMonth) temporal; |
| } |
| Objects.requireNonNull(temporal, "temporal"); |
| try { |
| if (IsoChronology.INSTANCE.equals(Chronology.from(temporal)) == false) { |
| temporal = LocalDate.from(temporal); |
| } |
| return of(temporal.get(YEAR), temporal.get(MONTH_OF_YEAR)); |
| } catch (DateTimeException ex) { |
| throw new DateTimeException("Unable to obtain YearMonth from TemporalAccessor: " + |
| temporal + " of type " + temporal.getClass().getName(), ex); |
| } |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Obtains an instance of {@code YearMonth} from a text string such as {@code 2007-12}. |
| * <p> |
| * The string must represent a valid year-month. |
| * The format must be {@code uuuu-MM}. |
| * Years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol. |
| * |
| * @param text the text to parse such as "2007-12", not null |
| * @return the parsed year-month, not null |
| * @throws DateTimeParseException if the text cannot be parsed |
| */ |
| public static YearMonth parse(CharSequence text) { |
| return parse(text, PARSER); |
| } |
| |
| /** |
| * Obtains an instance of {@code YearMonth} from a text string using a specific formatter. |
| * <p> |
| * The text is parsed using the formatter, returning a year-month. |
| * |
| * @param text the text to parse, not null |
| * @param formatter the formatter to use, not null |
| * @return the parsed year-month, not null |
| * @throws DateTimeParseException if the text cannot be parsed |
| */ |
| public static YearMonth parse(CharSequence text, DateTimeFormatter formatter) { |
| Objects.requireNonNull(formatter, "formatter"); |
| return formatter.parse(text, YearMonth::from); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Constructor. |
| * |
| * @param year the year to represent, validated from MIN_YEAR to MAX_YEAR |
| * @param month the month-of-year to represent, validated from 1 (January) to 12 (December) |
| */ |
| private YearMonth(int year, int month) { |
| this.year = year; |
| this.month = month; |
| } |
| |
| /** |
| * Returns a copy of this year-month with the new year and month, checking |
| * to see if a new object is in fact required. |
| * |
| * @param newYear the year to represent, validated from MIN_YEAR to MAX_YEAR |
| * @param newMonth the month-of-year to represent, validated not null |
| * @return the year-month, not null |
| */ |
| private YearMonth with(int newYear, int newMonth) { |
| if (year == newYear && month == newMonth) { |
| return this; |
| } |
| return new YearMonth(newYear, newMonth); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Checks if the specified field is supported. |
| * <p> |
| * This checks if this year-month can be queried for the specified field. |
| * If false, then calling the {@link #range(TemporalField) range}, |
| * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)} |
| * methods will throw an exception. |
| * <p> |
| * If the field is a {@link ChronoField} then the query is implemented here. |
| * The supported fields are: |
| * <ul> |
| * <li>{@code MONTH_OF_YEAR} |
| * <li>{@code PROLEPTIC_MONTH} |
| * <li>{@code YEAR_OF_ERA} |
| * <li>{@code YEAR} |
| * <li>{@code ERA} |
| * </ul> |
| * All other {@code ChronoField} instances will return false. |
| * <p> |
| * If the field is not a {@code ChronoField}, then the result of this method |
| * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)} |
| * passing {@code this} as the argument. |
| * Whether the field is supported is determined by the field. |
| * |
| * @param field the field to check, null returns false |
| * @return true if the field is supported on this year-month, false if not |
| */ |
| @Override |
| public boolean isSupported(TemporalField field) { |
| if (field instanceof ChronoField) { |
| return field == YEAR || field == MONTH_OF_YEAR || |
| field == PROLEPTIC_MONTH || field == YEAR_OF_ERA || field == ERA; |
| } |
| return field != null && field.isSupportedBy(this); |
| } |
| |
| /** |
| * Checks if the specified unit is supported. |
| * <p> |
| * This checks if the specified unit can be added to, or subtracted from, this year-month. |
| * If false, then calling the {@link #plus(long, TemporalUnit)} and |
| * {@link #minus(long, TemporalUnit) minus} methods will throw an exception. |
| * <p> |
| * If the unit is a {@link ChronoUnit} then the query is implemented here. |
| * The supported units are: |
| * <ul> |
| * <li>{@code MONTHS} |
| * <li>{@code YEARS} |
| * <li>{@code DECADES} |
| * <li>{@code CENTURIES} |
| * <li>{@code MILLENNIA} |
| * <li>{@code ERAS} |
| * </ul> |
| * All other {@code ChronoUnit} instances will return false. |
| * <p> |
| * If the unit is not a {@code ChronoUnit}, then the result of this method |
| * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)} |
| * passing {@code this} as the argument. |
| * Whether the unit is supported is determined by the unit. |
| * |
| * @param unit the unit to check, null returns false |
| * @return true if the unit can be added/subtracted, false if not |
| */ |
| @Override |
| public boolean isSupported(TemporalUnit unit) { |
| if (unit instanceof ChronoUnit) { |
| return unit == MONTHS || unit == YEARS || unit == DECADES || unit == CENTURIES || unit == MILLENNIA || unit == ERAS; |
| } |
| return unit != null && unit.isSupportedBy(this); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Gets the range of valid values for the specified field. |
| * <p> |
| * The range object expresses the minimum and maximum valid values for a field. |
| * This year-month is used to enhance the accuracy of the returned range. |
| * If it is not possible to return the range, because the field is not supported |
| * or for some other reason, an exception is thrown. |
| * <p> |
| * If the field is a {@link ChronoField} then the query is implemented here. |
| * The {@link #isSupported(TemporalField) supported fields} will return |
| * appropriate range instances. |
| * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. |
| * <p> |
| * If the field is not a {@code ChronoField}, then the result of this method |
| * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)} |
| * passing {@code this} as the argument. |
| * Whether the range can be obtained is determined by the field. |
| * |
| * @param field the field to query the range for, not null |
| * @return the range of valid values for the field, not null |
| * @throws DateTimeException if the range for the field cannot be obtained |
| * @throws UnsupportedTemporalTypeException if the field is not supported |
| */ |
| @Override |
| public ValueRange range(TemporalField field) { |
| if (field == YEAR_OF_ERA) { |
| return (getYear() <= 0 ? ValueRange.of(1, Year.MAX_VALUE + 1) : ValueRange.of(1, Year.MAX_VALUE)); |
| } |
| return Temporal.super.range(field); |
| } |
| |
| /** |
| * Gets the value of the specified field from this year-month as an {@code int}. |
| * <p> |
| * This queries this year-month for the value of the specified field. |
| * The returned value will always be within the valid range of values for the field. |
| * If it is not possible to return the value, because the field is not supported |
| * or for some other reason, an exception is thrown. |
| * <p> |
| * If the field is a {@link ChronoField} then the query is implemented here. |
| * The {@link #isSupported(TemporalField) supported fields} will return valid |
| * values based on this year-month, except {@code PROLEPTIC_MONTH} which is too |
| * large to fit in an {@code int} and throw a {@code DateTimeException}. |
| * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. |
| * <p> |
| * If the field is not a {@code ChronoField}, then the result of this method |
| * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)} |
| * passing {@code this} as the argument. Whether the value can be obtained, |
| * and what the value represents, is determined by the field. |
| * |
| * @param field the field to get, not null |
| * @return the value for the field |
| * @throws DateTimeException if a value for the field cannot be obtained or |
| * the value is outside the range of valid values for the field |
| * @throws UnsupportedTemporalTypeException if the field is not supported or |
| * the range of values exceeds an {@code int} |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override // override for Javadoc |
| public int get(TemporalField field) { |
| return range(field).checkValidIntValue(getLong(field), field); |
| } |
| |
| /** |
| * Gets the value of the specified field from this year-month as a {@code long}. |
| * <p> |
| * This queries this year-month for the value of the specified field. |
| * If it is not possible to return the value, because the field is not supported |
| * or for some other reason, an exception is thrown. |
| * <p> |
| * If the field is a {@link ChronoField} then the query is implemented here. |
| * The {@link #isSupported(TemporalField) supported fields} will return valid |
| * values based on this year-month. |
| * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. |
| * <p> |
| * If the field is not a {@code ChronoField}, then the result of this method |
| * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)} |
| * passing {@code this} as the argument. Whether the value can be obtained, |
| * and what the value represents, is determined by the field. |
| * |
| * @param field the field to get, not null |
| * @return the value for the field |
| * @throws DateTimeException if a value for the field cannot be obtained |
| * @throws UnsupportedTemporalTypeException if the field is not supported |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public long getLong(TemporalField field) { |
| if (field instanceof ChronoField) { |
| switch ((ChronoField) field) { |
| case MONTH_OF_YEAR: return month; |
| case PROLEPTIC_MONTH: return getProlepticMonth(); |
| case YEAR_OF_ERA: return (year < 1 ? 1 - year : year); |
| case YEAR: return year; |
| case ERA: return (year < 1 ? 0 : 1); |
| } |
| throw new UnsupportedTemporalTypeException("Unsupported field: " + field); |
| } |
| return field.getFrom(this); |
| } |
| |
| private long getProlepticMonth() { |
| return (year * 12L + month - 1); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Gets the year field. |
| * <p> |
| * This method returns the primitive {@code int} value for the year. |
| * <p> |
| * The year returned by this method is proleptic as per {@code get(YEAR)}. |
| * |
| * @return the year, from MIN_YEAR to MAX_YEAR |
| */ |
| public int getYear() { |
| return year; |
| } |
| |
| /** |
| * Gets the month-of-year field from 1 to 12. |
| * <p> |
| * This method returns the month as an {@code int} from 1 to 12. |
| * Application code is frequently clearer if the enum {@link Month} |
| * is used by calling {@link #getMonth()}. |
| * |
| * @return the month-of-year, from 1 to 12 |
| * @see #getMonth() |
| */ |
| public int getMonthValue() { |
| return month; |
| } |
| |
| /** |
| * Gets the month-of-year field using the {@code Month} enum. |
| * <p> |
| * This method returns the enum {@link Month} for the month. |
| * This avoids confusion as to what {@code int} values mean. |
| * If you need access to the primitive {@code int} value then the enum |
| * provides the {@link Month#getValue() int value}. |
| * |
| * @return the month-of-year, not null |
| * @see #getMonthValue() |
| */ |
| public Month getMonth() { |
| return Month.of(month); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Checks if the year is a leap year, according to the ISO proleptic |
| * calendar system rules. |
| * <p> |
| * This method applies the current rules for leap years across the whole time-line. |
| * In general, a year is a leap year if it is divisible by four without |
| * remainder. However, years divisible by 100, are not leap years, with |
| * the exception of years divisible by 400 which are. |
| * <p> |
| * For example, 1904 is a leap year it is divisible by 4. |
| * 1900 was not a leap year as it is divisible by 100, however 2000 was a |
| * leap year as it is divisible by 400. |
| * <p> |
| * The calculation is proleptic - applying the same rules into the far future and far past. |
| * This is historically inaccurate, but is correct for the ISO-8601 standard. |
| * |
| * @return true if the year is leap, false otherwise |
| */ |
| public boolean isLeapYear() { |
| return IsoChronology.INSTANCE.isLeapYear(year); |
| } |
| |
| /** |
| * Checks if the day-of-month is valid for this year-month. |
| * <p> |
| * This method checks whether this year and month and the input day form |
| * a valid date. |
| * |
| * @param dayOfMonth the day-of-month to validate, from 1 to 31, invalid value returns false |
| * @return true if the day is valid for this year-month |
| */ |
| public boolean isValidDay(int dayOfMonth) { |
| return dayOfMonth >= 1 && dayOfMonth <= lengthOfMonth(); |
| } |
| |
| /** |
| * Returns the length of the month, taking account of the year. |
| * <p> |
| * This returns the length of the month in days. |
| * For example, a date in January would return 31. |
| * |
| * @return the length of the month in days, from 28 to 31 |
| */ |
| public int lengthOfMonth() { |
| return getMonth().length(isLeapYear()); |
| } |
| |
| /** |
| * Returns the length of the year. |
| * <p> |
| * This returns the length of the year in days, either 365 or 366. |
| * |
| * @return 366 if the year is leap, 365 otherwise |
| */ |
| public int lengthOfYear() { |
| return (isLeapYear() ? 366 : 365); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Returns an adjusted copy of this year-month. |
| * <p> |
| * This returns a {@code YearMonth}, based on this one, with the year-month adjusted. |
| * The adjustment takes place using the specified adjuster strategy object. |
| * Read the documentation of the adjuster to understand what adjustment will be made. |
| * <p> |
| * A simple adjuster might simply set the one of the fields, such as the year field. |
| * A more complex adjuster might set the year-month to the next month that |
| * Halley's comet will pass the Earth. |
| * <p> |
| * The result of this method is obtained by invoking the |
| * {@link TemporalAdjuster#adjustInto(Temporal)} method on the |
| * specified adjuster passing {@code this} as the argument. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param adjuster the adjuster to use, not null |
| * @return a {@code YearMonth} based on {@code this} with the adjustment made, not null |
| * @throws DateTimeException if the adjustment cannot be made |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public YearMonth with(TemporalAdjuster adjuster) { |
| return (YearMonth) adjuster.adjustInto(this); |
| } |
| |
| /** |
| * Returns a copy of this year-month with the specified field set to a new value. |
| * <p> |
| * This returns a {@code YearMonth}, based on this one, with the value |
| * for the specified field changed. |
| * This can be used to change any supported field, such as the year or month. |
| * If it is not possible to set the value, because the field is not supported or for |
| * some other reason, an exception is thrown. |
| * <p> |
| * If the field is a {@link ChronoField} then the adjustment is implemented here. |
| * The supported fields behave as follows: |
| * <ul> |
| * <li>{@code MONTH_OF_YEAR} - |
| * Returns a {@code YearMonth} with the specified month-of-year. |
| * The year will be unchanged. |
| * <li>{@code PROLEPTIC_MONTH} - |
| * Returns a {@code YearMonth} with the specified proleptic-month. |
| * This completely replaces the year and month of this object. |
| * <li>{@code YEAR_OF_ERA} - |
| * Returns a {@code YearMonth} with the specified year-of-era |
| * The month and era will be unchanged. |
| * <li>{@code YEAR} - |
| * Returns a {@code YearMonth} with the specified year. |
| * The month will be unchanged. |
| * <li>{@code ERA} - |
| * Returns a {@code YearMonth} with the specified era. |
| * The month and year-of-era will be unchanged. |
| * </ul> |
| * <p> |
| * In all cases, if the new value is outside the valid range of values for the field |
| * then a {@code DateTimeException} will be thrown. |
| * <p> |
| * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. |
| * <p> |
| * If the field is not a {@code ChronoField}, then the result of this method |
| * is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)} |
| * passing {@code this} as the argument. In this case, the field determines |
| * whether and how to adjust the instant. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param field the field to set in the result, not null |
| * @param newValue the new value of the field in the result |
| * @return a {@code YearMonth} based on {@code this} with the specified field set, not null |
| * @throws DateTimeException if the field cannot be set |
| * @throws UnsupportedTemporalTypeException if the field is not supported |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public YearMonth with(TemporalField field, long newValue) { |
| if (field instanceof ChronoField) { |
| ChronoField f = (ChronoField) field; |
| f.checkValidValue(newValue); |
| switch (f) { |
| case MONTH_OF_YEAR: return withMonth((int) newValue); |
| case PROLEPTIC_MONTH: return plusMonths(newValue - getProlepticMonth()); |
| case YEAR_OF_ERA: return withYear((int) (year < 1 ? 1 - newValue : newValue)); |
| case YEAR: return withYear((int) newValue); |
| case ERA: return (getLong(ERA) == newValue ? this : withYear(1 - year)); |
| } |
| throw new UnsupportedTemporalTypeException("Unsupported field: " + field); |
| } |
| return field.adjustInto(this, newValue); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Returns a copy of this {@code YearMonth} with the year altered. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param year the year to set in the returned year-month, from MIN_YEAR to MAX_YEAR |
| * @return a {@code YearMonth} based on this year-month with the requested year, not null |
| * @throws DateTimeException if the year value is invalid |
| */ |
| public YearMonth withYear(int year) { |
| YEAR.checkValidValue(year); |
| return with(year, month); |
| } |
| |
| /** |
| * Returns a copy of this {@code YearMonth} with the month-of-year altered. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param month the month-of-year to set in the returned year-month, from 1 (January) to 12 (December) |
| * @return a {@code YearMonth} based on this year-month with the requested month, not null |
| * @throws DateTimeException if the month-of-year value is invalid |
| */ |
| public YearMonth withMonth(int month) { |
| MONTH_OF_YEAR.checkValidValue(month); |
| return with(year, month); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Returns a copy of this year-month with the specified amount added. |
| * <p> |
| * This returns a {@code YearMonth}, based on this one, with the specified amount added. |
| * The amount is typically {@link Period} but may be any other type implementing |
| * the {@link TemporalAmount} interface. |
| * <p> |
| * The calculation is delegated to the amount object by calling |
| * {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free |
| * to implement the addition in any way it wishes, however it typically |
| * calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation |
| * of the amount implementation to determine if it can be successfully added. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param amountToAdd the amount to add, not null |
| * @return a {@code YearMonth} based on this year-month with the addition made, not null |
| * @throws DateTimeException if the addition cannot be made |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public YearMonth plus(TemporalAmount amountToAdd) { |
| return (YearMonth) amountToAdd.addTo(this); |
| } |
| |
| /** |
| * Returns a copy of this year-month with the specified amount added. |
| * <p> |
| * This returns a {@code YearMonth}, based on this one, with the amount |
| * in terms of the unit added. If it is not possible to add the amount, because the |
| * unit is not supported or for some other reason, an exception is thrown. |
| * <p> |
| * If the field is a {@link ChronoUnit} then the addition is implemented here. |
| * The supported fields behave as follows: |
| * <ul> |
| * <li>{@code MONTHS} - |
| * Returns a {@code YearMonth} with the specified number of months added. |
| * This is equivalent to {@link #plusMonths(long)}. |
| * <li>{@code YEARS} - |
| * Returns a {@code YearMonth} with the specified number of years added. |
| * This is equivalent to {@link #plusYears(long)}. |
| * <li>{@code DECADES} - |
| * Returns a {@code YearMonth} with the specified number of decades added. |
| * This is equivalent to calling {@link #plusYears(long)} with the amount |
| * multiplied by 10. |
| * <li>{@code CENTURIES} - |
| * Returns a {@code YearMonth} with the specified number of centuries added. |
| * This is equivalent to calling {@link #plusYears(long)} with the amount |
| * multiplied by 100. |
| * <li>{@code MILLENNIA} - |
| * Returns a {@code YearMonth} with the specified number of millennia added. |
| * This is equivalent to calling {@link #plusYears(long)} with the amount |
| * multiplied by 1,000. |
| * <li>{@code ERAS} - |
| * Returns a {@code YearMonth} with the specified number of eras added. |
| * Only two eras are supported so the amount must be one, zero or minus one. |
| * If the amount is non-zero then the year is changed such that the year-of-era |
| * is unchanged. |
| * </ul> |
| * <p> |
| * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}. |
| * <p> |
| * If the field is not a {@code ChronoUnit}, then the result of this method |
| * is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)} |
| * passing {@code this} as the argument. In this case, the unit determines |
| * whether and how to perform the addition. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param amountToAdd the amount of the unit to add to the result, may be negative |
| * @param unit the unit of the amount to add, not null |
| * @return a {@code YearMonth} based on this year-month with the specified amount added, not null |
| * @throws DateTimeException if the addition cannot be made |
| * @throws UnsupportedTemporalTypeException if the unit is not supported |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public YearMonth plus(long amountToAdd, TemporalUnit unit) { |
| if (unit instanceof ChronoUnit) { |
| switch ((ChronoUnit) unit) { |
| case MONTHS: return plusMonths(amountToAdd); |
| case YEARS: return plusYears(amountToAdd); |
| case DECADES: return plusYears(Math.multiplyExact(amountToAdd, 10)); |
| case CENTURIES: return plusYears(Math.multiplyExact(amountToAdd, 100)); |
| case MILLENNIA: return plusYears(Math.multiplyExact(amountToAdd, 1000)); |
| case ERAS: return with(ERA, Math.addExact(getLong(ERA), amountToAdd)); |
| } |
| throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); |
| } |
| return unit.addTo(this, amountToAdd); |
| } |
| |
| /** |
| * Returns a copy of this {@code YearMonth} with the specified number of years added. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param yearsToAdd the years to add, may be negative |
| * @return a {@code YearMonth} based on this year-month with the years added, not null |
| * @throws DateTimeException if the result exceeds the supported range |
| */ |
| public YearMonth plusYears(long yearsToAdd) { |
| if (yearsToAdd == 0) { |
| return this; |
| } |
| int newYear = YEAR.checkValidIntValue(year + yearsToAdd); // safe overflow |
| return with(newYear, month); |
| } |
| |
| /** |
| * Returns a copy of this {@code YearMonth} with the specified number of months added. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param monthsToAdd the months to add, may be negative |
| * @return a {@code YearMonth} based on this year-month with the months added, not null |
| * @throws DateTimeException if the result exceeds the supported range |
| */ |
| public YearMonth plusMonths(long monthsToAdd) { |
| if (monthsToAdd == 0) { |
| return this; |
| } |
| long monthCount = year * 12L + (month - 1); |
| long calcMonths = monthCount + monthsToAdd; // safe overflow |
| int newYear = YEAR.checkValidIntValue(Math.floorDiv(calcMonths, 12)); |
| int newMonth = (int)Math.floorMod(calcMonths, 12) + 1; |
| return with(newYear, newMonth); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Returns a copy of this year-month with the specified amount subtracted. |
| * <p> |
| * This returns a {@code YearMonth}, based on this one, with the specified amount subtracted. |
| * The amount is typically {@link Period} but may be any other type implementing |
| * the {@link TemporalAmount} interface. |
| * <p> |
| * The calculation is delegated to the amount object by calling |
| * {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free |
| * to implement the subtraction in any way it wishes, however it typically |
| * calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation |
| * of the amount implementation to determine if it can be successfully subtracted. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param amountToSubtract the amount to subtract, not null |
| * @return a {@code YearMonth} based on this year-month with the subtraction made, not null |
| * @throws DateTimeException if the subtraction cannot be made |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public YearMonth minus(TemporalAmount amountToSubtract) { |
| return (YearMonth) amountToSubtract.subtractFrom(this); |
| } |
| |
| /** |
| * Returns a copy of this year-month with the specified amount subtracted. |
| * <p> |
| * This returns a {@code YearMonth}, based on this one, with the amount |
| * in terms of the unit subtracted. If it is not possible to subtract the amount, |
| * because the unit is not supported or for some other reason, an exception is thrown. |
| * <p> |
| * This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated. |
| * See that method for a full description of how addition, and thus subtraction, works. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param amountToSubtract the amount of the unit to subtract from the result, may be negative |
| * @param unit the unit of the amount to subtract, not null |
| * @return a {@code YearMonth} based on this year-month with the specified amount subtracted, not null |
| * @throws DateTimeException if the subtraction cannot be made |
| * @throws UnsupportedTemporalTypeException if the unit is not supported |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public YearMonth minus(long amountToSubtract, TemporalUnit unit) { |
| return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit)); |
| } |
| |
| /** |
| * Returns a copy of this {@code YearMonth} with the specified number of years subtracted. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param yearsToSubtract the years to subtract, may be negative |
| * @return a {@code YearMonth} based on this year-month with the years subtracted, not null |
| * @throws DateTimeException if the result exceeds the supported range |
| */ |
| public YearMonth minusYears(long yearsToSubtract) { |
| return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract)); |
| } |
| |
| /** |
| * Returns a copy of this {@code YearMonth} with the specified number of months subtracted. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param monthsToSubtract the months to subtract, may be negative |
| * @return a {@code YearMonth} based on this year-month with the months subtracted, not null |
| * @throws DateTimeException if the result exceeds the supported range |
| */ |
| public YearMonth minusMonths(long monthsToSubtract) { |
| return (monthsToSubtract == Long.MIN_VALUE ? plusMonths(Long.MAX_VALUE).plusMonths(1) : plusMonths(-monthsToSubtract)); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Queries this year-month using the specified query. |
| * <p> |
| * This queries this year-month using the specified query strategy object. |
| * The {@code TemporalQuery} object defines the logic to be used to |
| * obtain the result. Read the documentation of the query to understand |
| * what the result of this method will be. |
| * <p> |
| * The result of this method is obtained by invoking the |
| * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the |
| * specified query passing {@code this} as the argument. |
| * |
| * @param <R> the type of the result |
| * @param query the query to invoke, not null |
| * @return the query result, null may be returned (defined by the query) |
| * @throws DateTimeException if unable to query (defined by the query) |
| * @throws ArithmeticException if numeric overflow occurs (defined by the query) |
| */ |
| @SuppressWarnings("unchecked") |
| @Override |
| public <R> R query(TemporalQuery<R> query) { |
| if (query == TemporalQueries.chronology()) { |
| return (R) IsoChronology.INSTANCE; |
| } else if (query == TemporalQueries.precision()) { |
| return (R) MONTHS; |
| } |
| return Temporal.super.query(query); |
| } |
| |
| /** |
| * Adjusts the specified temporal object to have this year-month. |
| * <p> |
| * This returns a temporal object of the same observable type as the input |
| * with the year and month changed to be the same as this. |
| * <p> |
| * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)} |
| * passing {@link ChronoField#PROLEPTIC_MONTH} as the field. |
| * If the specified temporal object does not use the ISO calendar system then |
| * a {@code DateTimeException} is thrown. |
| * <p> |
| * In most cases, it is clearer to reverse the calling pattern by using |
| * {@link Temporal#with(TemporalAdjuster)}: |
| * <pre> |
| * // these two lines are equivalent, but the second approach is recommended |
| * temporal = thisYearMonth.adjustInto(temporal); |
| * temporal = temporal.with(thisYearMonth); |
| * </pre> |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param temporal the target object to be adjusted, not null |
| * @return the adjusted object, not null |
| * @throws DateTimeException if unable to make the adjustment |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public Temporal adjustInto(Temporal temporal) { |
| if (Chronology.from(temporal).equals(IsoChronology.INSTANCE) == false) { |
| throw new DateTimeException("Adjustment only supported on ISO date-time"); |
| } |
| return temporal.with(PROLEPTIC_MONTH, getProlepticMonth()); |
| } |
| |
| /** |
| * Calculates the amount of time until another year-month in terms of the specified unit. |
| * <p> |
| * This calculates the amount of time between two {@code YearMonth} |
| * objects in terms of a single {@code TemporalUnit}. |
| * The start and end points are {@code this} and the specified year-month. |
| * The result will be negative if the end is before the start. |
| * The {@code Temporal} passed to this method is converted to a |
| * {@code YearMonth} using {@link #from(TemporalAccessor)}. |
| * For example, the amount in years between two year-months can be calculated |
| * using {@code startYearMonth.until(endYearMonth, YEARS)}. |
| * <p> |
| * The calculation returns a whole number, representing the number of |
| * complete units between the two year-months. |
| * For example, the amount in decades between 2012-06 and 2032-05 |
| * will only be one decade as it is one month short of two decades. |
| * <p> |
| * There are two equivalent ways of using this method. |
| * The first is to invoke this method. |
| * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}: |
| * <pre> |
| * // these two lines are equivalent |
| * amount = start.until(end, MONTHS); |
| * amount = MONTHS.between(start, end); |
| * </pre> |
| * The choice should be made based on which makes the code more readable. |
| * <p> |
| * The calculation is implemented in this method for {@link ChronoUnit}. |
| * The units {@code MONTHS}, {@code YEARS}, {@code DECADES}, |
| * {@code CENTURIES}, {@code MILLENNIA} and {@code ERAS} are supported. |
| * Other {@code ChronoUnit} values will throw an exception. |
| * <p> |
| * If the unit is not a {@code ChronoUnit}, then the result of this method |
| * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)} |
| * passing {@code this} as the first argument and the converted input temporal |
| * as the second argument. |
| * <p> |
| * This instance is immutable and unaffected by this method call. |
| * |
| * @param endExclusive the end date, exclusive, which is converted to a {@code YearMonth}, not null |
| * @param unit the unit to measure the amount in, not null |
| * @return the amount of time between this year-month and the end year-month |
| * @throws DateTimeException if the amount cannot be calculated, or the end |
| * temporal cannot be converted to a {@code YearMonth} |
| * @throws UnsupportedTemporalTypeException if the unit is not supported |
| * @throws ArithmeticException if numeric overflow occurs |
| */ |
| @Override |
| public long until(Temporal endExclusive, TemporalUnit unit) { |
| YearMonth end = YearMonth.from(endExclusive); |
| if (unit instanceof ChronoUnit) { |
| long monthsUntil = end.getProlepticMonth() - getProlepticMonth(); // no overflow |
| switch ((ChronoUnit) unit) { |
| case MONTHS: return monthsUntil; |
| case YEARS: return monthsUntil / 12; |
| case DECADES: return monthsUntil / 120; |
| case CENTURIES: return monthsUntil / 1200; |
| case MILLENNIA: return monthsUntil / 12000; |
| case ERAS: return end.getLong(ERA) - getLong(ERA); |
| } |
| throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); |
| } |
| return unit.between(this, end); |
| } |
| |
| /** |
| * Formats this year-month using the specified formatter. |
| * <p> |
| * This year-month will be passed to the formatter to produce a string. |
| * |
| * @param formatter the formatter to use, not null |
| * @return the formatted year-month string, not null |
| * @throws DateTimeException if an error occurs during printing |
| */ |
| public String format(DateTimeFormatter formatter) { |
| Objects.requireNonNull(formatter, "formatter"); |
| return formatter.format(this); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Combines this year-month with a day-of-month to create a {@code LocalDate}. |
| * <p> |
| * This returns a {@code LocalDate} formed from this year-month and the specified day-of-month. |
| * <p> |
| * The day-of-month value must be valid for the year-month. |
| * <p> |
| * This method can be used as part of a chain to produce a date: |
| * <pre> |
| * LocalDate date = year.atMonth(month).atDay(day); |
| * </pre> |
| * |
| * @param dayOfMonth the day-of-month to use, from 1 to 31 |
| * @return the date formed from this year-month and the specified day, not null |
| * @throws DateTimeException if the day is invalid for the year-month |
| * @see #isValidDay(int) |
| */ |
| public LocalDate atDay(int dayOfMonth) { |
| return LocalDate.of(year, month, dayOfMonth); |
| } |
| |
| /** |
| * Returns a {@code LocalDate} at the end of the month. |
| * <p> |
| * This returns a {@code LocalDate} based on this year-month. |
| * The day-of-month is set to the last valid day of the month, taking |
| * into account leap years. |
| * <p> |
| * This method can be used as part of a chain to produce a date: |
| * <pre> |
| * LocalDate date = year.atMonth(month).atEndOfMonth(); |
| * </pre> |
| * |
| * @return the last valid date of this year-month, not null |
| */ |
| public LocalDate atEndOfMonth() { |
| return LocalDate.of(year, month, lengthOfMonth()); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Compares this year-month to another year-month. |
| * <p> |
| * The comparison is based first on the value of the year, then on the value of the month. |
| * It is "consistent with equals", as defined by {@link Comparable}. |
| * |
| * @param other the other year-month to compare to, not null |
| * @return the comparator value, negative if less, positive if greater |
| */ |
| @Override |
| public int compareTo(YearMonth other) { |
| int cmp = (year - other.year); |
| if (cmp == 0) { |
| cmp = (month - other.month); |
| } |
| return cmp; |
| } |
| |
| /** |
| * Checks if this year-month is after the specified year-month. |
| * |
| * @param other the other year-month to compare to, not null |
| * @return true if this is after the specified year-month |
| */ |
| public boolean isAfter(YearMonth other) { |
| return compareTo(other) > 0; |
| } |
| |
| /** |
| * Checks if this year-month is before the specified year-month. |
| * |
| * @param other the other year-month to compare to, not null |
| * @return true if this point is before the specified year-month |
| */ |
| public boolean isBefore(YearMonth other) { |
| return compareTo(other) < 0; |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Checks if this year-month is equal to another year-month. |
| * <p> |
| * The comparison is based on the time-line position of the year-months. |
| * |
| * @param obj the object to check, null returns false |
| * @return true if this is equal to the other year-month |
| */ |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj instanceof YearMonth) { |
| YearMonth other = (YearMonth) obj; |
| return year == other.year && month == other.month; |
| } |
| return false; |
| } |
| |
| /** |
| * A hash code for this year-month. |
| * |
| * @return a suitable hash code |
| */ |
| @Override |
| public int hashCode() { |
| return year ^ (month << 27); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Outputs this year-month as a {@code String}, such as {@code 2007-12}. |
| * <p> |
| * The output will be in the format {@code uuuu-MM}: |
| * |
| * @return a string representation of this year-month, not null |
| */ |
| @Override |
| public String toString() { |
| int absYear = Math.abs(year); |
| StringBuilder buf = new StringBuilder(9); |
| if (absYear < 1000) { |
| if (year < 0) { |
| buf.append(year - 10000).deleteCharAt(1); |
| } else { |
| buf.append(year + 10000).deleteCharAt(0); |
| } |
| } else { |
| buf.append(year); |
| } |
| return buf.append(month < 10 ? "-0" : "-") |
| .append(month) |
| .toString(); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Writes the object using a |
| * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>. |
| * @serialData |
| * <pre> |
| * out.writeByte(12); // identifies a YearMonth |
| * out.writeInt(year); |
| * out.writeByte(month); |
| * </pre> |
| * |
| * @return the instance of {@code Ser}, not null |
| */ |
| private Object writeReplace() { |
| return new Ser(Ser.YEAR_MONTH_TYPE, this); |
| } |
| |
| /** |
| * Defend against malicious streams. |
| * |
| * @param s the stream to read |
| * @throws InvalidObjectException always |
| */ |
| private void readObject(ObjectInputStream s) throws InvalidObjectException { |
| throw new InvalidObjectException("Deserialization via serialization delegate"); |
| } |
| |
| void writeExternal(DataOutput out) throws IOException { |
| out.writeInt(year); |
| out.writeByte(month); |
| } |
| |
| static YearMonth readExternal(DataInput in) throws IOException { |
| int year = in.readInt(); |
| byte month = in.readByte(); |
| return YearMonth.of(year, month); |
| } |
| |
| } |
