Java tutorial
/* * Copyright (c) 2012, 2019, 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) 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.chrono; import static java.time.temporal.ChronoField.HOUR_OF_DAY; import static java.time.temporal.ChronoField.MINUTE_OF_HOUR; import static java.time.temporal.ChronoField.SECOND_OF_MINUTE; import java.time.Clock; import java.time.DateTimeException; import java.time.Instant; import java.time.LocalDate; import java.time.LocalTime; import java.time.ZoneId; import java.time.ZoneOffset; import java.time.format.DateTimeFormatterBuilder; import java.time.format.ResolverStyle; import java.time.format.TextStyle; import java.time.temporal.ChronoField; import java.time.temporal.TemporalAccessor; import java.time.temporal.TemporalField; import java.time.temporal.TemporalQueries; import java.time.temporal.TemporalQuery; import java.time.temporal.UnsupportedTemporalTypeException; import java.time.temporal.ValueRange; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Objects; import java.util.Set; /** * A calendar system, used to organize and identify dates. * <p> * The main date and time API is built on the ISO calendar system. * The chronology operates behind the scenes to represent the general concept of a calendar system. * For example, the Japanese, Minguo, Thai Buddhist and others. * <p> * Most other calendar systems also operate on the shared concepts of year, month and day, * linked to the cycles of the Earth around the Sun, and the Moon around the Earth. * These shared concepts are defined by {@link ChronoField} and are available * for use by any {@code Chronology} implementation: * <pre> * LocalDate isoDate = ... * ThaiBuddhistDate thaiDate = ... * int isoYear = isoDate.get(ChronoField.YEAR); * int thaiYear = thaiDate.get(ChronoField.YEAR); * </pre> * As shown, although the date objects are in different calendar systems, represented by different * {@code Chronology} instances, both can be queried using the same constant on {@code ChronoField}. * For a full discussion of the implications of this, see {@link ChronoLocalDate}. * In general, the advice is to use the known ISO-based {@code LocalDate}, rather than * {@code ChronoLocalDate}. * <p> * While a {@code Chronology} object typically uses {@code ChronoField} and is based on * an era, year-of-era, month-of-year, day-of-month model of a date, this is not required. * A {@code Chronology} instance may represent a totally different kind of calendar system, * such as the Mayan. * <p> * In practical terms, the {@code Chronology} instance also acts as a factory. * The {@link #of(String)} method allows an instance to be looked up by identifier, * while the {@link #ofLocale(Locale)} method allows lookup by locale. * <p> * The {@code Chronology} instance provides a set of methods to create {@code ChronoLocalDate} instances. * The date classes are used to manipulate specific dates. * <ul> * <li> {@link #dateNow() dateNow()} * <li> {@link #dateNow(Clock) dateNow(clock)} * <li> {@link #dateNow(ZoneId) dateNow(zone)} * <li> {@link #date(int, int, int) date(yearProleptic, month, day)} * <li> {@link #date(Era, int, int, int) date(era, yearOfEra, month, day)} * <li> {@link #dateYearDay(int, int) dateYearDay(yearProleptic, dayOfYear)} * <li> {@link #dateYearDay(Era, int, int) dateYearDay(era, yearOfEra, dayOfYear)} * <li> {@link #date(TemporalAccessor) date(TemporalAccessor)} * </ul> * * <h2 id="addcalendars">Adding New Calendars</h2> * The set of available chronologies can be extended by applications. * Adding a new calendar system requires the writing of an implementation of * {@code Chronology}, {@code ChronoLocalDate} and {@code Era}. * The majority of the logic specific to the calendar system will be in the * {@code ChronoLocalDate} implementation. * The {@code Chronology} implementation acts as a factory. * <p> * To permit the discovery of additional chronologies, the {@link java.util.ServiceLoader ServiceLoader} * is used. A file must be added to the {@code META-INF/services} directory with the * name 'java.time.chrono.Chronology' listing the implementation classes. * See the ServiceLoader for more details on service loading. * For lookup by id or calendarType, the system provided calendars are found * first followed by application provided calendars. * <p> * Each chronology must define a chronology ID that is unique within the system. * If the chronology represents a calendar system defined by the * CLDR specification then the calendar type is the concatenation of the * CLDR type and, if applicable, the CLDR variant. * * @implSpec * This interface must be implemented with care to ensure other classes operate correctly. * All implementations that can be instantiated must be final, immutable and thread-safe. * Subclasses should be Serializable wherever possible. * * @since 1.8 */ public interface Chronology extends Comparable<Chronology> { /** * Obtains an instance of {@code Chronology} from a temporal object. * <p> * This obtains a chronology 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 Chronology}. * <p> * The conversion will obtain the chronology using {@link TemporalQueries#chronology()}. * If the specified temporal object does not have a chronology, {@link IsoChronology} is returned. * <p> * This method matches the signature of the functional interface {@link TemporalQuery} * allowing it to be used as a query via method reference, {@code Chronology::from}. * * @param temporal the temporal to convert, not null * @return the chronology, not null * @throws DateTimeException if unable to convert to a {@code Chronology} */ static Chronology from(TemporalAccessor temporal) { Objects.requireNonNull(temporal, "temporal"); Chronology obj = temporal.query(TemporalQueries.chronology()); return Objects.requireNonNullElse(obj, IsoChronology.INSTANCE); } //----------------------------------------------------------------------- /** * Obtains an instance of {@code Chronology} from a locale. * <p> * This returns a {@code Chronology} based on the specified locale, * typically returning {@code IsoChronology}. Other calendar systems * are only returned if they are explicitly selected within the locale. * <p> * The {@link Locale} class provide access to a range of information useful * for localizing an application. This includes the language and region, * such as "en-GB" for English as used in Great Britain. * <p> * The {@code Locale} class also supports an extension mechanism that * can be used to identify a calendar system. The mechanism is a form * of key-value pairs, where the calendar system has the key "ca". * For example, the locale "en-JP-u-ca-japanese" represents the English * language as used in Japan with the Japanese calendar system. * <p> * This method finds the desired calendar system in a manner equivalent * to passing "ca" to {@link Locale#getUnicodeLocaleType(String)}. * If the "ca" key is not present, then {@code IsoChronology} is returned. * <p> * Note that the behavior of this method differs from the older * {@link java.util.Calendar#getInstance(Locale)} method. * If that method receives a locale of "th_TH" it will return {@code BuddhistCalendar}. * By contrast, this method will return {@code IsoChronology}. * Passing the locale "th-TH-u-ca-buddhist" into either method will * result in the Thai Buddhist calendar system and is therefore the * recommended approach going forward for Thai calendar system localization. * <p> * A similar, but simpler, situation occurs for the Japanese calendar system. * The locale "jp_JP_JP" has previously been used to access the calendar. * However, unlike the Thai locale, "ja_JP_JP" is automatically converted by * {@code Locale} to the modern and recommended form of "ja-JP-u-ca-japanese". * Thus, there is no difference in behavior between this method and * {@code Calendar#getInstance(Locale)}. * * @param locale the locale to use to obtain the calendar system, not null * @return the calendar system associated with the locale, not null * @throws DateTimeException if the locale-specified calendar cannot be found */ static Chronology ofLocale(Locale locale) { return AbstractChronology.ofLocale(locale); } //----------------------------------------------------------------------- /** * Obtains an instance of {@code Chronology} from a chronology ID or * calendar system type. * <p> * This returns a chronology based on either the ID or the type. * The {@link #getId() chronology ID} uniquely identifies the chronology. * The {@link #getCalendarType() calendar system type} is defined by the * CLDR specification. * <p> * The chronology may be a system chronology or a chronology * provided by the application via ServiceLoader configuration. * <p> * Since some calendars can be customized, the ID or type typically refers * to the default customization. For example, the Gregorian calendar can have multiple * cutover dates from the Julian, but the lookup only provides the default cutover date. * * @param id the chronology ID or calendar system type, not null * @return the chronology with the identifier requested, not null * @throws DateTimeException if the chronology cannot be found */ static Chronology of(String id) { return AbstractChronology.of(id); } /** * Returns the available chronologies. * <p> * Each returned {@code Chronology} is available for use in the system. * The set of chronologies includes the system chronologies and * any chronologies provided by the application via ServiceLoader * configuration. * * @return the independent, modifiable set of the available chronology IDs, not null */ static Set<Chronology> getAvailableChronologies() { return AbstractChronology.getAvailableChronologies(); } //----------------------------------------------------------------------- /** * Gets the ID of the chronology. * <p> * The ID uniquely identifies the {@code Chronology}. * It can be used to lookup the {@code Chronology} using {@link #of(String)}. * * @return the chronology ID, not null * @see #getCalendarType() */ String getId(); /** * Gets the calendar type of the calendar system. * <p> * The calendar type is an identifier defined by the CLDR and * <em>Unicode Locale Data Markup Language (LDML)</em> specifications * to uniquely identify a calendar. * The {@code getCalendarType} is the concatenation of the CLDR calendar type * and the variant, if applicable, is appended separated by "-". * The calendar type is used to lookup the {@code Chronology} using {@link #of(String)}. * * @return the calendar system type, null if the calendar is not defined by CLDR/LDML * @see #getId() */ String getCalendarType(); //----------------------------------------------------------------------- /** * Obtains a local date in this chronology from the era, year-of-era, * month-of-year and day-of-month fields. * * @implSpec * The default implementation combines the era and year-of-era into a proleptic * year before calling {@link #date(int, int, int)}. * * @param era the era of the correct type for the chronology, not null * @param yearOfEra the chronology year-of-era * @param month the chronology month-of-year * @param dayOfMonth the chronology day-of-month * @return the local date in this chronology, not null * @throws DateTimeException if unable to create the date * @throws ClassCastException if the {@code era} is not of the correct type for the chronology */ default ChronoLocalDate date(Era era, int yearOfEra, int month, int dayOfMonth) { return date(prolepticYear(era, yearOfEra), month, dayOfMonth); } /** * Obtains a local date in this chronology from the proleptic-year, * month-of-year and day-of-month fields. * * @param prolepticYear the chronology proleptic-year * @param month the chronology month-of-year * @param dayOfMonth the chronology day-of-month * @return the local date in this chronology, not null * @throws DateTimeException if unable to create the date */ ChronoLocalDate date(int prolepticYear, int month, int dayOfMonth); /** * Obtains a local date in this chronology from the era, year-of-era and * day-of-year fields. * * @implSpec * The default implementation combines the era and year-of-era into a proleptic * year before calling {@link #dateYearDay(int, int)}. * * @param era the era of the correct type for the chronology, not null * @param yearOfEra the chronology year-of-era * @param dayOfYear the chronology day-of-year * @return the local date in this chronology, not null * @throws DateTimeException if unable to create the date * @throws ClassCastException if the {@code era} is not of the correct type for the chronology */ default ChronoLocalDate dateYearDay(Era era, int yearOfEra, int dayOfYear) { return dateYearDay(prolepticYear(era, yearOfEra), dayOfYear); } /** * Obtains a local date in this chronology from the proleptic-year and * day-of-year fields. * * @param prolepticYear the chronology proleptic-year * @param dayOfYear the chronology day-of-year * @return the local date in this chronology, not null * @throws DateTimeException if unable to create the date */ ChronoLocalDate dateYearDay(int prolepticYear, int dayOfYear); /** * Obtains a local date in this chronology from the epoch-day. * <p> * The definition of {@link ChronoField#EPOCH_DAY EPOCH_DAY} is the same * for all calendar systems, thus it can be used for conversion. * * @param epochDay the epoch day * @return the local date in this chronology, not null * @throws DateTimeException if unable to create the date */ ChronoLocalDate dateEpochDay(long epochDay); //----------------------------------------------------------------------- /** * Obtains the current local date in this chronology 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 date. * <p> * Using this method will prevent the ability to use an alternate clock for testing * because the clock is hard-coded. * * @implSpec * The default implementation invokes {@link #dateNow(Clock)}. * * @return the current local date using the system clock and default time-zone, not null * @throws DateTimeException if unable to create the date */ default ChronoLocalDate dateNow() { return dateNow(Clock.systemDefaultZone()); } /** * Obtains the current local date in this chronology from the system clock in the specified time-zone. * <p> * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date. * 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. * * @implSpec * The default implementation invokes {@link #dateNow(Clock)}. * * @param zone the zone ID to use, not null * @return the current local date using the system clock, not null * @throws DateTimeException if unable to create the date */ default ChronoLocalDate dateNow(ZoneId zone) { return dateNow(Clock.system(zone)); } /** * Obtains the current local date in this chronology from the specified clock. * <p> * This will query the specified clock to obtain the current date - today. * Using this method allows the use of an alternate clock for testing. * The alternate clock may be introduced using {@link Clock dependency injection}. * * @implSpec * The default implementation invokes {@link #date(TemporalAccessor)}. * * @param clock the clock to use, not null * @return the current local date, not null * @throws DateTimeException if unable to create the date */ default ChronoLocalDate dateNow(Clock clock) { Objects.requireNonNull(clock, "clock"); return date(LocalDate.now(clock)); } //----------------------------------------------------------------------- /** * Obtains a local date in this chronology from another temporal object. * <p> * This obtains a date in this chronology 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 ChronoLocalDate}. * <p> * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY} * field, which is standardized across calendar systems. * <p> * This method matches the signature of the functional interface {@link TemporalQuery} * allowing it to be used as a query via method reference, {@code aChronology::date}. * * @param temporal the temporal object to convert, not null * @return the local date in this chronology, not null * @throws DateTimeException if unable to create the date * @see ChronoLocalDate#from(TemporalAccessor) */ ChronoLocalDate date(TemporalAccessor temporal); /** * Obtains a local date-time in this chronology from another temporal object. * <p> * This obtains a date-time in this chronology 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 ChronoLocalDateTime}. * <p> * The conversion extracts and combines the {@code ChronoLocalDate} and the * {@code LocalTime} from the temporal object. * Implementations are permitted to perform optimizations such as accessing * those fields that are equivalent to the relevant objects. * The result uses this chronology. * <p> * This method matches the signature of the functional interface {@link TemporalQuery} * allowing it to be used as a query via method reference, {@code aChronology::localDateTime}. * * @param temporal the temporal object to convert, not null * @return the local date-time in this chronology, not null * @throws DateTimeException if unable to create the date-time * @see ChronoLocalDateTime#from(TemporalAccessor) */ default ChronoLocalDateTime<? extends ChronoLocalDate> localDateTime(TemporalAccessor temporal) { try { return date(temporal).atTime(LocalTime.from(temporal)); } catch (DateTimeException ex) { throw new DateTimeException( "Unable to obtain ChronoLocalDateTime from TemporalAccessor: " + temporal.getClass(), ex); } } /** * Obtains a {@code ChronoZonedDateTime} in this chronology from another temporal object. * <p> * This obtains a zoned date-time in this chronology 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 ChronoZonedDateTime}. * <p> * The conversion will first obtain a {@code ZoneId} from the temporal object, * falling back to a {@code ZoneOffset} if necessary. It will then try to obtain * an {@code Instant}, falling back to a {@code ChronoLocalDateTime} if necessary. * The result will be either the combination of {@code ZoneId} or {@code ZoneOffset} * with {@code Instant} or {@code ChronoLocalDateTime}. * Implementations are permitted to perform optimizations such as accessing * those fields that are equivalent to the relevant objects. * The result uses this chronology. * <p> * This method matches the signature of the functional interface {@link TemporalQuery} * allowing it to be used as a query via method reference, {@code aChronology::zonedDateTime}. * * @param temporal the temporal object to convert, not null * @return the zoned date-time in this chronology, not null * @throws DateTimeException if unable to create the date-time * @see ChronoZonedDateTime#from(TemporalAccessor) */ default ChronoZonedDateTime<? extends ChronoLocalDate> zonedDateTime(TemporalAccessor temporal) { try { ZoneId zone = ZoneId.from(temporal); try { Instant instant = Instant.from(temporal); return zonedDateTime(instant, zone); } catch (DateTimeException ex1) { ChronoLocalDateTimeImpl<?> cldt = ChronoLocalDateTimeImpl.ensureValid(this, localDateTime(temporal)); return ChronoZonedDateTimeImpl.ofBest(cldt, zone, null); } } catch (DateTimeException ex) { throw new DateTimeException( "Unable to obtain ChronoZonedDateTime from TemporalAccessor: " + temporal.getClass(), ex); } } /** * Obtains a {@code ChronoZonedDateTime} in this chronology from an {@code Instant}. * <p> * This obtains a zoned date-time with the same instant as that specified. * * @param instant the instant to create the date-time from, not null * @param zone the time-zone, not null * @return the zoned date-time, not null * @throws DateTimeException if the result exceeds the supported range */ default ChronoZonedDateTime<? extends ChronoLocalDate> zonedDateTime(Instant instant, ZoneId zone) { return ChronoZonedDateTimeImpl.ofInstant(this, instant, zone); } //----------------------------------------------------------------------- /** * Checks if the specified year is a leap year. * <p> * A leap-year is a year of a longer length than normal. * The exact meaning is determined by the chronology according to the following constraints. * <ul> * <li>a leap-year must imply a year-length longer than a non leap-year. * <li>a chronology that does not support the concept of a year must return false. * <li>the correct result must be returned for all years within the * valid range of years for the chronology. * </ul> * <p> * Outside the range of valid years an implementation is free to return * either a best guess or false. * An implementation must not throw an exception, even if the year is * outside the range of valid years. * * @param prolepticYear the proleptic-year to check, not validated for range * @return true if the year is a leap year */ boolean isLeapYear(long prolepticYear); /** * Calculates the proleptic-year given the era and year-of-era. * <p> * This combines the era and year-of-era into the single proleptic-year field. * <p> * If the chronology makes active use of eras, such as {@code JapaneseChronology} * then the year-of-era will be validated against the era. * For other chronologies, validation is optional. * * @param era the era of the correct type for the chronology, not null * @param yearOfEra the chronology year-of-era * @return the proleptic-year * @throws DateTimeException if unable to convert to a proleptic-year, * such as if the year is invalid for the era * @throws ClassCastException if the {@code era} is not of the correct type for the chronology */ int prolepticYear(Era era, int yearOfEra); /** * Creates the chronology era object from the numeric value. * <p> * The era is, conceptually, the largest division of the time-line. * Most calendar systems have a single epoch dividing the time-line into two eras. * However, some have multiple eras, such as one for the reign of each leader. * The exact meaning is determined by the chronology according to the following constraints. * <p> * The era in use at 1970-01-01 must have the value 1. * Later eras must have sequentially higher values. * Earlier eras must have sequentially lower values. * Each chronology must refer to an enum or similar singleton to provide the era values. * <p> * This method returns the singleton era of the correct type for the specified era value. * * @param eraValue the era value * @return the calendar system era, not null * @throws DateTimeException if unable to create the era */ Era eraOf(int eraValue); /** * Gets the list of eras for the chronology. * <p> * Most calendar systems have an era, within which the year has meaning. * If the calendar system does not support the concept of eras, an empty * list must be returned. * * @return the list of eras for the chronology, may be immutable, not null */ List<Era> eras(); //----------------------------------------------------------------------- /** * Gets the range of valid values for the specified field. * <p> * All fields can be expressed as a {@code long} integer. * This method returns an object that describes the valid range for that value. * <p> * Note that the result only describes the minimum and maximum valid values * and it is important not to read too much into them. For example, there * could be values within the range that are invalid for the field. * <p> * This method will return a result whether or not the chronology supports the field. * * @param field the field to get 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 */ ValueRange range(ChronoField field); //----------------------------------------------------------------------- /** * Gets the textual representation of this chronology. * <p> * This returns the textual name used to identify the chronology, * suitable for presentation to the user. * The parameters control the style of the returned text and the locale. * * @implSpec * The default implementation behaves as though the formatter was used to * format the chronology textual name. * * @param style the style of the text required, not null * @param locale the locale to use, not null * @return the text value of the chronology, not null */ default String getDisplayName(TextStyle style, Locale locale) { TemporalAccessor temporal = new TemporalAccessor() { @Override public boolean isSupported(TemporalField field) { return false; } @Override public long getLong(TemporalField field) { throw new UnsupportedTemporalTypeException("Unsupported field: " + field); } @SuppressWarnings("unchecked") @Override public <R> R query(TemporalQuery<R> query) { if (query == TemporalQueries.chronology()) { return (R) Chronology.this; } return TemporalAccessor.super.query(query); } }; return new DateTimeFormatterBuilder().appendChronologyText(style).toFormatter(locale).format(temporal); } //----------------------------------------------------------------------- /** * Resolves parsed {@code ChronoField} values into a date during parsing. * <p> * Most {@code TemporalField} implementations are resolved using the * resolve method on the field. By contrast, the {@code ChronoField} class * defines fields that only have meaning relative to the chronology. * As such, {@code ChronoField} date fields are resolved here in the * context of a specific chronology. * <p> * The default implementation, which explains typical resolve behaviour, * is provided in {@link AbstractChronology}. * * @param fieldValues the map of fields to values, which can be updated, not null * @param resolverStyle the requested type of resolve, not null * @return the resolved date, null if insufficient information to create a date * @throws DateTimeException if the date cannot be resolved, typically * because of a conflict in the input data */ ChronoLocalDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle); //----------------------------------------------------------------------- /** * Obtains a period for this chronology based on years, months and days. * <p> * This returns a period tied to this chronology using the specified * years, months and days. All supplied chronologies use periods * based on years, months and days, however the {@code ChronoPeriod} API * allows the period to be represented using other units. * * @implSpec * The default implementation returns an implementation class suitable * for most calendar systems. It is based solely on the three units. * Normalization, addition and subtraction derive the number of months * in a year from the {@link #range(ChronoField)}. If the number of * months within a year is fixed, then the calculation approach for * addition, subtraction and normalization is slightly different. * <p> * If implementing an unusual calendar system that is not based on * years, months and days, or where you want direct control, then * the {@code ChronoPeriod} interface must be directly implemented. * <p> * The returned period is immutable and thread-safe. * * @param years the number of years, may be negative * @param months the number of years, may be negative * @param days the number of years, may be negative * @return the period in terms of this chronology, not null */ default ChronoPeriod period(int years, int months, int days) { return new ChronoPeriodImpl(this, years, months, days); } //--------------------------------------------------------------------- /** * Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z. * <p> * The number of seconds is calculated using the proleptic-year, * month, day-of-month, hour, minute, second, and zoneOffset. * * @param prolepticYear the chronology proleptic-year * @param month the chronology month-of-year * @param dayOfMonth the chronology day-of-month * @param hour the hour-of-day, from 0 to 23 * @param minute the minute-of-hour, from 0 to 59 * @param second the second-of-minute, from 0 to 59 * @param zoneOffset the zone offset, not null * @return the number of seconds relative to 1970-01-01T00:00:00Z, may be negative * @throws DateTimeException if any of the values are out of range * @since 9 */ public default long epochSecond(int prolepticYear, int month, int dayOfMonth, int hour, int minute, int second, ZoneOffset zoneOffset) { Objects.requireNonNull(zoneOffset, "zoneOffset"); HOUR_OF_DAY.checkValidValue(hour); MINUTE_OF_HOUR.checkValidValue(minute); SECOND_OF_MINUTE.checkValidValue(second); long daysInSec = Math.multiplyExact(date(prolepticYear, month, dayOfMonth).toEpochDay(), 86400); long timeinSec = (hour * 60 + minute) * 60 + second; return Math.addExact(daysInSec, timeinSec - zoneOffset.getTotalSeconds()); } /** * Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z. * <p> * The number of seconds is calculated using the era, year-of-era, * month, day-of-month, hour, minute, second, and zoneOffset. * * @param era the era of the correct type for the chronology, not null * @param yearOfEra the chronology year-of-era * @param month the chronology month-of-year * @param dayOfMonth the chronology day-of-month * @param hour the hour-of-day, from 0 to 23 * @param minute the minute-of-hour, from 0 to 59 * @param second the second-of-minute, from 0 to 59 * @param zoneOffset the zone offset, not null * @return the number of seconds relative to 1970-01-01T00:00:00Z, may be negative * @throws DateTimeException if any of the values are out of range * @since 9 */ public default long epochSecond(Era era, int yearOfEra, int month, int dayOfMonth, int hour, int minute, int second, ZoneOffset zoneOffset) { Objects.requireNonNull(era, "era"); return epochSecond(prolepticYear(era, yearOfEra), month, dayOfMonth, hour, minute, second, zoneOffset); } //----------------------------------------------------------------------- /** * Compares this chronology to another chronology. * <p> * The comparison order first by the chronology ID string, then by any * additional information specific to the subclass. * It is "consistent with equals", as defined by {@link Comparable}. * * @param other the other chronology to compare to, not null * @return the comparator value, negative if less, positive if greater */ @Override int compareTo(Chronology other); /** * Checks if this chronology is equal to another chronology. * <p> * The comparison is based on the entire state of the object. * * @param obj the object to check, null returns false * @return true if this is equal to the other chronology */ @Override boolean equals(Object obj); /** * A hash code for this chronology. * <p> * The hash code should be based on the entire state of the object. * * @return a suitable hash code */ @Override int hashCode(); //----------------------------------------------------------------------- /** * Outputs this chronology as a {@code String}. * <p> * The format should include the entire state of the object. * * @return a string representation of this chronology, not null */ @Override String toString(); }