--- a/jdk/src/share/classes/java/time/temporal/YearMonth.java Tue Feb 12 16:02:14 2013 +0400
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,1085 +0,0 @@
-/*
- * Copyright (c) 2012, 2013, 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.temporal;
-
-import static java.time.temporal.ChronoField.EPOCH_MONTH;
-import static java.time.temporal.ChronoField.ERA;
-import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
-import static java.time.temporal.ChronoField.YEAR;
-import static java.time.temporal.ChronoField.YEAR_OF_ERA;
-import static java.time.temporal.ChronoUnit.MONTHS;
-
-import java.io.DataInput;
-import java.io.DataOutput;
-import java.io.IOException;
-import java.io.InvalidObjectException;
-import java.io.ObjectStreamException;
-import java.io.Serializable;
-import java.time.Clock;
-import java.time.DateTimeException;
-import java.time.LocalDate;
-import java.time.Month;
-import java.time.ZoneId;
-import java.time.format.DateTimeFormatter;
-import java.time.format.DateTimeFormatterBuilder;
-import java.time.format.DateTimeParseException;
-import java.time.format.SignStyle;
-import java.util.Objects;
-
-/**
- * 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.
- *
- * <h3>Specification for implementors</h3>
- * 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 java.time.Clock#systemDefaultZone() system clock} in the default
- * time-zone to obtain the current year-month.
- * The zone and offset will be set based on the time-zone in the clock.
- * <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(java.time.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>
- * A {@code TemporalAccessor} represents some form of date and time information.
- * This factory converts the arbitrary temporal object 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 in queries 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;
- }
- try {
- if (ISOChrono.INSTANCE.equals(Chrono.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.getClass(), 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 yyyy-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} and
- * {@link #get(TemporalField) get} methods will throw an exception.
- * <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 date-time.
- * The supported fields are:
- * <ul>
- * <li>{@code MONTH_OF_YEAR}
- * <li>{@code EPOCH_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.doIsSupported(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 == EPOCH_MONTH || field == YEAR_OF_ERA || field == ERA;
- }
- return field != null && field.doIsSupported(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 a {@code DateTimeException}.
- * <p>
- * If the field is not a {@code ChronoField}, then the result of this method
- * is obtained by invoking {@code TemporalField.doRange(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
- */
- @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 for 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 EPOCH_MONTH} which is too
- * large to fit in an {@code int} and throw a {@code DateTimeException}.
- * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
- * <p>
- * If the field is not a {@code ChronoField}, then the result of this method
- * is obtained by invoking {@code TemporalField.doGet(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 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 for 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 a {@code DateTimeException}.
- * <p>
- * If the field is not a {@code ChronoField}, then the result of this method
- * is obtained by invoking {@code TemporalField.doGet(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 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 EPOCH_MONTH: return getEpochMonth();
- case YEAR_OF_ERA: return (year < 1 ? 1 - year : year);
- case YEAR: return year;
- case ERA: return (year < 1 ? 0 : 1);
- }
- throw new DateTimeException("Unsupported field: " + field.getName());
- }
- return field.doGet(this);
- }
-
- private long getEpochMonth() {
- return ((year - 1970) * 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 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
- */
- 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 ISOChrono.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 new {@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 new {@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 EPOCH_MONTH} -
- * Returns a {@code YearMonth} with the specified epoch-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 a {@code DateTimeException}.
- * <p>
- * If the field is not a {@code ChronoField}, then the result of this method
- * is obtained by invoking {@code TemporalField.doWith(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 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 EPOCH_MONTH: return plusMonths(newValue - getLong(EPOCH_MONTH));
- 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 DateTimeException("Unsupported field: " + field.getName());
- }
- return field.doWith(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 period added.
- * <p>
- * This method returns a new year-month based on this year-month with the specified period added.
- * The adder is typically {@link java.time.Period} but may be any other type implementing
- * the {@link TemporalAdder} interface.
- * The calculation is delegated to the specified adjuster, which typically calls
- * back to {@link #plus(long, TemporalUnit)}.
- * <p>
- * This instance is immutable and unaffected by this method call.
- *
- * @param adder the adder to use, 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(TemporalAdder adder) {
- return (YearMonth) adder.addTo(this);
- }
-
- /**
- * {@inheritDoc}
- * @throws DateTimeException {@inheritDoc}
- * @throws ArithmeticException {@inheritDoc}
- */
- @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 DateTimeException("Unsupported unit: " + unit.getName());
- }
- return unit.doPlus(this, amountToAdd);
- }
-
- /**
- * Returns a copy of this year-month with the specified period in 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 year-month with the specified period in 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 period subtracted.
- * <p>
- * This method returns a new year-month based on this year-month with the specified period subtracted.
- * The subtractor is typically {@link java.time.Period} but may be any other type implementing
- * the {@link TemporalSubtractor} interface.
- * The calculation is delegated to the specified adjuster, which typically calls
- * back to {@link #minus(long, TemporalUnit)}.
- * <p>
- * This instance is immutable and unaffected by this method call.
- *
- * @param subtractor the subtractor to use, 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(TemporalSubtractor subtractor) {
- return (YearMonth) subtractor.subtractFrom(this);
- }
-
- /**
- * {@inheritDoc}
- * @throws DateTimeException {@inheritDoc}
- * @throws ArithmeticException {@inheritDoc}
- */
- @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 year-month with the specified period in 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 year-month with the specified period in 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 == Queries.chrono()) {
- return (R) ISOChrono.INSTANCE;
- } else if (query == Queries.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#EPOCH_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 (Chrono.from(temporal).equals(ISOChrono.INSTANCE) == false) {
- throw new DateTimeException("Adjustment only supported on ISO date-time");
- }
- return temporal.with(EPOCH_MONTH, getEpochMonth());
- }
-
- /**
- * Calculates the period between this year-month and another year-month in
- * terms of the specified unit.
- * <p>
- * This calculates the period between two year-months in terms of a single unit.
- * 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 must be a {@code YearMonth}.
- * For example, the period in years between two year-months can be calculated
- * using {@code startYearMonth.periodUntil(endYearMonth, YEARS)}.
- * <p>
- * The calculation returns a whole number, representing the number of
- * complete units between the two year-months.
- * For example, the period in decades between 2012-06 and 2032-05
- * will only be one decade as it is one month short of two decades.
- * <p>
- * This method operates in association with {@link TemporalUnit#between}.
- * The result of this method is a {@code long} representing the amount of
- * the specified unit. By contrast, the result of {@code between} is an
- * object that can be used directly in addition/subtraction:
- * <pre>
- * long period = start.periodUntil(end, YEARS); // this method
- * dateTime.plus(YEARS.between(start, end)); // use in plus/minus
- * </pre>
- * <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 input temporal as
- * the second argument.
- * <p>
- * This instance is immutable and unaffected by this method call.
- *
- * @param endYearMonth the end year-month, which must be a {@code YearMonth}, not null
- * @param unit the unit to measure the period in, not null
- * @return the amount of the period between this year-month and the end year-month
- * @throws DateTimeException if the period cannot be calculated
- * @throws ArithmeticException if numeric overflow occurs
- */
- @Override
- public long periodUntil(Temporal endYearMonth, TemporalUnit unit) {
- if (endYearMonth instanceof YearMonth == false) {
- Objects.requireNonNull(endYearMonth, "endYearMonth");
- throw new DateTimeException("Unable to calculate period between objects of two different types");
- }
- YearMonth end = (YearMonth) endYearMonth;
- if (unit instanceof ChronoUnit) {
- long monthsUntil = end.getEpochMonth() - getEpochMonth(); // 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 DateTimeException("Unsupported unit: " + unit.getName());
- }
- return unit.between(this, endYearMonth).getAmount();
- }
-
- //-----------------------------------------------------------------------
- /**
- * Returns a date formed from this year-month at the specified day-of-month.
- * <p>
- * This combines this year-month and the specified day-of-month to form a {@code LocalDate}.
- * 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>
- * <p>
- * This instance is immutable and unaffected by this method call.
- *
- * @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 when the day is invalid for the year-month
- * @see #isValidDay(int)
- */
- public LocalDate atDay(int dayOfMonth) {
- return LocalDate.of(year, month, dayOfMonth);
- }
-
- //-----------------------------------------------------------------------
- /**
- * 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;
- }
-
- /**
- * Is this year-month 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;
- }
-
- /**
- * Is this year-month 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 yyyy-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();
- }
-
- /**
- * Outputs this year-month as a {@code String} using the formatter.
- * <p>
- * This year-month will be passed to the formatter
- * {@link DateTimeFormatter#print(TemporalAccessor) print method}.
- *
- * @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 toString(DateTimeFormatter formatter) {
- Objects.requireNonNull(formatter, "formatter");
- return formatter.print(this);
- }
-
- //-----------------------------------------------------------------------
- /**
- * Writes the object using a
- * <a href="../../../serialized-form.html#java.time.temporal.Ser">dedicated serialized form</a>.
- * <pre>
- * out.writeByte(5); // identifies this as a Year
- * 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.
- * @return never
- * @throws InvalidObjectException always
- */
- private Object readResolve() throws ObjectStreamException {
- 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);
- }
-
-}