Java tutorial
/* * Copyright (c) 2012, 2017, 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. */ /* * 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.temporal; import static java.time.temporal.ChronoUnit.DAYS; import static java.time.temporal.ChronoUnit.ERAS; import static java.time.temporal.ChronoUnit.FOREVER; import static java.time.temporal.ChronoUnit.HALF_DAYS; import static java.time.temporal.ChronoUnit.HOURS; import static java.time.temporal.ChronoUnit.MICROS; import static java.time.temporal.ChronoUnit.MILLIS; import static java.time.temporal.ChronoUnit.MINUTES; import static java.time.temporal.ChronoUnit.MONTHS; import static java.time.temporal.ChronoUnit.NANOS; import static java.time.temporal.ChronoUnit.SECONDS; import static java.time.temporal.ChronoUnit.WEEKS; import static java.time.temporal.ChronoUnit.YEARS; import java.time.DayOfWeek; import java.time.Instant; import java.time.Year; import java.time.ZoneOffset; import java.time.chrono.ChronoLocalDate; import java.time.chrono.Chronology; import java.util.Locale; import java.util.Objects; import java.util.ResourceBundle; import sun.util.locale.provider.CalendarDataUtility; import sun.util.locale.provider.LocaleProviderAdapter; import sun.util.locale.provider.LocaleResources; /** * A standard set of fields. * <p> * This set of fields provide field-based access to manipulate a date, time or date-time. * The standard set of fields can be extended by implementing {@link TemporalField}. * <p> * These fields are intended to be applicable in multiple calendar systems. * For example, most non-ISO calendar systems define dates as a year, month and day, * just with slightly different rules. * The documentation of each field explains how it operates. * * @implSpec * This is a final, immutable and thread-safe enum. * * @since 1.8 */ public enum ChronoField implements TemporalField { /** * The nano-of-second. * <p> * This counts the nanosecond within the second, from 0 to 999,999,999. * This field has the same meaning for all calendar systems. * <p> * This field is used to represent the nano-of-second handling any fraction of the second. * Implementations of {@code TemporalAccessor} should provide a value for this field if * they can return a value for {@link #SECOND_OF_MINUTE}, {@link #SECOND_OF_DAY} or * {@link #INSTANT_SECONDS} filling unknown precision with zero. * <p> * When this field is used for setting a value, it should set as much precision as the * object stores, using integer division to remove excess precision. * For example, if the {@code TemporalAccessor} stores time to millisecond precision, * then the nano-of-second must be divided by 1,000,000 before replacing the milli-of-second. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The field is resolved in combination with {@code MILLI_OF_SECOND} and {@code MICRO_OF_SECOND}. */ NANO_OF_SECOND("NanoOfSecond", NANOS, SECONDS, ValueRange.of(0, 999_999_999)), /** * The nano-of-day. * <p> * This counts the nanosecond within the day, from 0 to (24 * 60 * 60 * 1,000,000,000) - 1. * This field has the same meaning for all calendar systems. * <p> * This field is used to represent the nano-of-day handling any fraction of the second. * Implementations of {@code TemporalAccessor} should provide a value for this field if * they can return a value for {@link #SECOND_OF_DAY} filling unknown precision with zero. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The value is split to form {@code NANO_OF_SECOND}, {@code SECOND_OF_MINUTE}, * {@code MINUTE_OF_HOUR} and {@code HOUR_OF_DAY} fields. */ NANO_OF_DAY("NanoOfDay", NANOS, DAYS, ValueRange.of(0, 86400L * 1000_000_000L - 1)), /** * The micro-of-second. * <p> * This counts the microsecond within the second, from 0 to 999,999. * This field has the same meaning for all calendar systems. * <p> * This field is used to represent the micro-of-second handling any fraction of the second. * Implementations of {@code TemporalAccessor} should provide a value for this field if * they can return a value for {@link #SECOND_OF_MINUTE}, {@link #SECOND_OF_DAY} or * {@link #INSTANT_SECONDS} filling unknown precision with zero. * <p> * When this field is used for setting a value, it should behave in the same way as * setting {@link #NANO_OF_SECOND} with the value multiplied by 1,000. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The field is resolved in combination with {@code MILLI_OF_SECOND} to produce * {@code NANO_OF_SECOND}. */ MICRO_OF_SECOND("MicroOfSecond", MICROS, SECONDS, ValueRange.of(0, 999_999)), /** * The micro-of-day. * <p> * This counts the microsecond within the day, from 0 to (24 * 60 * 60 * 1,000,000) - 1. * This field has the same meaning for all calendar systems. * <p> * This field is used to represent the micro-of-day handling any fraction of the second. * Implementations of {@code TemporalAccessor} should provide a value for this field if * they can return a value for {@link #SECOND_OF_DAY} filling unknown precision with zero. * <p> * When this field is used for setting a value, it should behave in the same way as * setting {@link #NANO_OF_DAY} with the value multiplied by 1,000. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The value is split to form {@code MICRO_OF_SECOND}, {@code SECOND_OF_MINUTE}, * {@code MINUTE_OF_HOUR} and {@code HOUR_OF_DAY} fields. */ MICRO_OF_DAY("MicroOfDay", MICROS, DAYS, ValueRange.of(0, 86400L * 1000_000L - 1)), /** * The milli-of-second. * <p> * This counts the millisecond within the second, from 0 to 999. * This field has the same meaning for all calendar systems. * <p> * This field is used to represent the milli-of-second handling any fraction of the second. * Implementations of {@code TemporalAccessor} should provide a value for this field if * they can return a value for {@link #SECOND_OF_MINUTE}, {@link #SECOND_OF_DAY} or * {@link #INSTANT_SECONDS} filling unknown precision with zero. * <p> * When this field is used for setting a value, it should behave in the same way as * setting {@link #NANO_OF_SECOND} with the value multiplied by 1,000,000. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The field is resolved in combination with {@code MICRO_OF_SECOND} to produce * {@code NANO_OF_SECOND}. */ MILLI_OF_SECOND("MilliOfSecond", MILLIS, SECONDS, ValueRange.of(0, 999)), /** * The milli-of-day. * <p> * This counts the millisecond within the day, from 0 to (24 * 60 * 60 * 1,000) - 1. * This field has the same meaning for all calendar systems. * <p> * This field is used to represent the milli-of-day handling any fraction of the second. * Implementations of {@code TemporalAccessor} should provide a value for this field if * they can return a value for {@link #SECOND_OF_DAY} filling unknown precision with zero. * <p> * When this field is used for setting a value, it should behave in the same way as * setting {@link #NANO_OF_DAY} with the value multiplied by 1,000,000. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The value is split to form {@code MILLI_OF_SECOND}, {@code SECOND_OF_MINUTE}, * {@code MINUTE_OF_HOUR} and {@code HOUR_OF_DAY} fields. */ MILLI_OF_DAY("MilliOfDay", MILLIS, DAYS, ValueRange.of(0, 86400L * 1000L - 1)), /** * The second-of-minute. * <p> * This counts the second within the minute, from 0 to 59. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. */ SECOND_OF_MINUTE("SecondOfMinute", SECONDS, MINUTES, ValueRange.of(0, 59), "second"), /** * The second-of-day. * <p> * This counts the second within the day, from 0 to (24 * 60 * 60) - 1. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The value is split to form {@code SECOND_OF_MINUTE}, {@code MINUTE_OF_HOUR} * and {@code HOUR_OF_DAY} fields. */ SECOND_OF_DAY("SecondOfDay", SECONDS, DAYS, ValueRange.of(0, 86400L - 1)), /** * The minute-of-hour. * <p> * This counts the minute within the hour, from 0 to 59. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. */ MINUTE_OF_HOUR("MinuteOfHour", MINUTES, HOURS, ValueRange.of(0, 59), "minute"), /** * The minute-of-day. * <p> * This counts the minute within the day, from 0 to (24 * 60) - 1. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The value is split to form {@code MINUTE_OF_HOUR} and {@code HOUR_OF_DAY} fields. */ MINUTE_OF_DAY("MinuteOfDay", MINUTES, DAYS, ValueRange.of(0, (24 * 60) - 1)), /** * The hour-of-am-pm. * <p> * This counts the hour within the AM/PM, from 0 to 11. * This is the hour that would be observed on a standard 12-hour digital clock. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated from 0 to 11 in strict and smart mode. * In lenient mode the value is not validated. It is combined with * {@code AMPM_OF_DAY} to form {@code HOUR_OF_DAY} by multiplying * the {AMPM_OF_DAY} value by 12. * <p> * See {@link #CLOCK_HOUR_OF_AMPM} for the related field that counts hours from 1 to 12. */ HOUR_OF_AMPM("HourOfAmPm", HOURS, HALF_DAYS, ValueRange.of(0, 11)), /** * The clock-hour-of-am-pm. * <p> * This counts the hour within the AM/PM, from 1 to 12. * This is the hour that would be observed on a standard 12-hour analog wall clock. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated from 1 to 12 in strict mode and from * 0 to 12 in smart mode. In lenient mode the value is not validated. * The field is converted to an {@code HOUR_OF_AMPM} with the same value, * unless the value is 12, in which case it is converted to 0. * <p> * See {@link #HOUR_OF_AMPM} for the related field that counts hours from 0 to 11. */ CLOCK_HOUR_OF_AMPM("ClockHourOfAmPm", HOURS, HALF_DAYS, ValueRange.of(1, 12)), /** * The hour-of-day. * <p> * This counts the hour within the day, from 0 to 23. * This is the hour that would be observed on a standard 24-hour digital clock. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated in strict and smart mode but not in lenient mode. * The field is combined with {@code MINUTE_OF_HOUR}, {@code SECOND_OF_MINUTE} and * {@code NANO_OF_SECOND} to produce a {@code LocalTime}. * In lenient mode, any excess days are added to the parsed date, or * made available via {@link java.time.format.DateTimeFormatter#parsedExcessDays()}. * <p> * See {@link #CLOCK_HOUR_OF_DAY} for the related field that counts hours from 1 to 24. */ HOUR_OF_DAY("HourOfDay", HOURS, DAYS, ValueRange.of(0, 23), "hour"), /** * The clock-hour-of-day. * <p> * This counts the hour within the day, from 1 to 24. * This is the hour that would be observed on a 24-hour analog wall clock. * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated from 1 to 24 in strict mode and from * 0 to 24 in smart mode. In lenient mode the value is not validated. * The field is converted to an {@code HOUR_OF_DAY} with the same value, * unless the value is 24, in which case it is converted to 0. * <p> * See {@link #HOUR_OF_DAY} for the related field that counts hours from 0 to 23. */ CLOCK_HOUR_OF_DAY("ClockHourOfDay", HOURS, DAYS, ValueRange.of(1, 24)), /** * The am-pm-of-day. * <p> * This counts the AM/PM within the day, from 0 (AM) to 1 (PM). * This field has the same meaning for all calendar systems. * <p> * When parsing this field it behaves equivalent to the following: * The value is validated from 0 to 1 in strict and smart mode. * In lenient mode the value is not validated. It is combined with * {@code HOUR_OF_AMPM} to form {@code HOUR_OF_DAY} by multiplying * the {AMPM_OF_DAY} value by 12. */ AMPM_OF_DAY("AmPmOfDay", HALF_DAYS, DAYS, ValueRange.of(0, 1), "dayperiod"), /** * The day-of-week, such as Tuesday. * <p> * This represents the standard concept of the day of the week. * In the default ISO calendar system, this has values from Monday (1) to Sunday (7). * The {@link DayOfWeek} class can be used to interpret the result. * <p> * Most non-ISO calendar systems also define a seven day week that aligns with ISO. * Those calendar systems must also use the same numbering system, from Monday (1) to * Sunday (7), which allows {@code DayOfWeek} to be used. * <p> * Calendar systems that do not have a standard seven day week should implement this field * if they have a similar concept of named or numbered days within a period similar * to a week. It is recommended that the numbering starts from 1. */ DAY_OF_WEEK("DayOfWeek", DAYS, WEEKS, ValueRange.of(1, 7), "weekday"), /** * The aligned day-of-week within a month. * <p> * This represents concept of the count of days within the period of a week * where the weeks are aligned to the start of the month. * This field is typically used with {@link #ALIGNED_WEEK_OF_MONTH}. * <p> * For example, in a calendar systems with a seven day week, the first aligned-week-of-month * starts on day-of-month 1, the second aligned-week starts on day-of-month 8, and so on. * Within each of these aligned-weeks, the days are numbered from 1 to 7 and returned * as the value of this field. * As such, day-of-month 1 to 7 will have aligned-day-of-week values from 1 to 7. * And day-of-month 8 to 14 will repeat this with aligned-day-of-week values from 1 to 7. * <p> * Calendar systems that do not have a seven day week should typically implement this * field in the same way, but using the alternate week length. */ ALIGNED_DAY_OF_WEEK_IN_MONTH("AlignedDayOfWeekInMonth", DAYS, WEEKS, ValueRange.of(1, 7)), /** * The aligned day-of-week within a year. * <p> * This represents concept of the count of days within the period of a week * where the weeks are aligned to the start of the year. * This field is typically used with {@link #ALIGNED_WEEK_OF_YEAR}. * <p> * For example, in a calendar systems with a seven day week, the first aligned-week-of-year * starts on day-of-year 1, the second aligned-week starts on day-of-year 8, and so on. * Within each of these aligned-weeks, the days are numbered from 1 to 7 and returned * as the value of this field. * As such, day-of-year 1 to 7 will have aligned-day-of-week values from 1 to 7. * And day-of-year 8 to 14 will repeat this with aligned-day-of-week values from 1 to 7. * <p> * Calendar systems that do not have a seven day week should typically implement this * field in the same way, but using the alternate week length. */ ALIGNED_DAY_OF_WEEK_IN_YEAR("AlignedDayOfWeekInYear", DAYS, WEEKS, ValueRange.of(1, 7)), /** * The day-of-month. * <p> * This represents the concept of the day within the month. * In the default ISO calendar system, this has values from 1 to 31 in most months. * April, June, September, November have days from 1 to 30, while February has days * from 1 to 28, or 29 in a leap year. * <p> * Non-ISO calendar systems should implement this field using the most recognized * day-of-month values for users of the calendar system. * Normally, this is a count of days from 1 to the length of the month. */ DAY_OF_MONTH("DayOfMonth", DAYS, MONTHS, ValueRange.of(1, 28, 31), "day"), /** * The day-of-year. * <p> * This represents the concept of the day within the year. * In the default ISO calendar system, this has values from 1 to 365 in standard * years and 1 to 366 in leap years. * <p> * Non-ISO calendar systems should implement this field using the most recognized * day-of-year values for users of the calendar system. * Normally, this is a count of days from 1 to the length of the year. * <p> * Note that a non-ISO calendar system may have year numbering system that changes * at a different point to the natural reset in the month numbering. An example * of this is the Japanese calendar system where a change of era, which resets * the year number to 1, can happen on any date. The era and year reset also cause * the day-of-year to be reset to 1, but not the month-of-year or day-of-month. */ DAY_OF_YEAR("DayOfYear", DAYS, YEARS, ValueRange.of(1, 365, 366)), /** * The epoch-day, based on the Java epoch of 1970-01-01 (ISO). * <p> * This field is the sequential count of days where 1970-01-01 (ISO) is zero. * Note that this uses the <i>local</i> time-line, ignoring offset and time-zone. * <p> * This field is strictly defined to have the same meaning in all calendar systems. * This is necessary to ensure interoperation between calendars. * <p> * Range of EpochDay is between (LocalDate.MIN.toEpochDay(), LocalDate.MAX.toEpochDay()) * both inclusive. */ EPOCH_DAY("EpochDay", DAYS, FOREVER, ValueRange.of(-365243219162L, 365241780471L)), /** * The aligned week within a month. * <p> * This represents concept of the count of weeks within the period of a month * where the weeks are aligned to the start of the month. * This field is typically used with {@link #ALIGNED_DAY_OF_WEEK_IN_MONTH}. * <p> * For example, in a calendar systems with a seven day week, the first aligned-week-of-month * starts on day-of-month 1, the second aligned-week starts on day-of-month 8, and so on. * Thus, day-of-month values 1 to 7 are in aligned-week 1, while day-of-month values * 8 to 14 are in aligned-week 2, and so on. * <p> * Calendar systems that do not have a seven day week should typically implement this * field in the same way, but using the alternate week length. */ ALIGNED_WEEK_OF_MONTH("AlignedWeekOfMonth", WEEKS, MONTHS, ValueRange.of(1, 4, 5)), /** * The aligned week within a year. * <p> * This represents concept of the count of weeks within the period of a year * where the weeks are aligned to the start of the year. * This field is typically used with {@link #ALIGNED_DAY_OF_WEEK_IN_YEAR}. * <p> * For example, in a calendar systems with a seven day week, the first aligned-week-of-year * starts on day-of-year 1, the second aligned-week starts on day-of-year 8, and so on. * Thus, day-of-year values 1 to 7 are in aligned-week 1, while day-of-year values * 8 to 14 are in aligned-week 2, and so on. * <p> * Calendar systems that do not have a seven day week should typically implement this * field in the same way, but using the alternate week length. */ ALIGNED_WEEK_OF_YEAR("AlignedWeekOfYear", WEEKS, YEARS, ValueRange.of(1, 53)), /** * The month-of-year, such as March. * <p> * This represents the concept of the month within the year. * In the default ISO calendar system, this has values from January (1) to December (12). * <p> * Non-ISO calendar systems should implement this field using the most recognized * month-of-year values for users of the calendar system. * Normally, this is a count of months starting from 1. */ MONTH_OF_YEAR("MonthOfYear", MONTHS, YEARS, ValueRange.of(1, 12), "month"), /** * The proleptic-month based, counting months sequentially from year 0. * <p> * This field is the sequential count of months where the first month * in proleptic-year zero has the value zero. * Later months have increasingly larger values. * Earlier months have increasingly small values. * There are no gaps or breaks in the sequence of months. * Note that this uses the <i>local</i> time-line, ignoring offset and time-zone. * <p> * In the default ISO calendar system, June 2012 would have the value * {@code (2012 * 12 + 6 - 1)}. This field is primarily for internal use. * <p> * Non-ISO calendar systems must implement this field as per the definition above. * It is just a simple zero-based count of elapsed months from the start of proleptic-year 0. * All calendar systems with a full proleptic-year definition will have a year zero. * If the calendar system has a minimum year that excludes year zero, then one must * be extrapolated in order for this method to be defined. */ PROLEPTIC_MONTH("ProlepticMonth", MONTHS, FOREVER, ValueRange.of(Year.MIN_VALUE * 12L, Year.MAX_VALUE * 12L + 11)), /** * The year within the era. * <p> * This represents the concept of the year within the era. * This field is typically used with {@link #ERA}. * <p> * The standard mental model for a date is based on three concepts - year, month and day. * These map onto the {@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} fields. * Note that there is no reference to eras. * The full model for a date requires four concepts - era, year, month and day. These map onto * the {@code ERA}, {@code YEAR_OF_ERA}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} fields. * Whether this field or {@code YEAR} is used depends on which mental model is being used. * See {@link ChronoLocalDate} for more discussion on this topic. * <p> * In the default ISO calendar system, there are two eras defined, 'BCE' and 'CE'. * The era 'CE' is the one currently in use and year-of-era runs from 1 to the maximum value. * The era 'BCE' is the previous era, and the year-of-era runs backwards. * <p> * For example, subtracting a year each time yield the following:<br> * - year-proleptic 2 = 'CE' year-of-era 2<br> * - year-proleptic 1 = 'CE' year-of-era 1<br> * - year-proleptic 0 = 'BCE' year-of-era 1<br> * - year-proleptic -1 = 'BCE' year-of-era 2<br> * <p> * Note that the ISO-8601 standard does not actually define eras. * Note also that the ISO eras do not align with the well-known AD/BC eras due to the * change between the Julian and Gregorian calendar systems. * <p> * Non-ISO calendar systems should implement this field using the most recognized * year-of-era value for users of the calendar system. * Since most calendar systems have only two eras, the year-of-era numbering approach * will typically be the same as that used by the ISO calendar system. * The year-of-era value should typically always be positive, however this is not required. */ YEAR_OF_ERA("YearOfEra", YEARS, FOREVER, ValueRange.of(1, Year.MAX_VALUE, Year.MAX_VALUE + 1)), /** * The proleptic year, such as 2012. * <p> * This represents the concept of the year, counting sequentially and using negative numbers. * The proleptic year is not interpreted in terms of the era. * See {@link #YEAR_OF_ERA} for an example showing the mapping from proleptic year to year-of-era. * <p> * The standard mental model for a date is based on three concepts - year, month and day. * These map onto the {@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} fields. * Note that there is no reference to eras. * The full model for a date requires four concepts - era, year, month and day. These map onto * the {@code ERA}, {@code YEAR_OF_ERA}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} fields. * Whether this field or {@code YEAR_OF_ERA} is used depends on which mental model is being used. * See {@link ChronoLocalDate} for more discussion on this topic. * <p> * Non-ISO calendar systems should implement this field as follows. * If the calendar system has only two eras, before and after a fixed date, then the * proleptic-year value must be the same as the year-of-era value for the later era, * and increasingly negative for the earlier era. * If the calendar system has more than two eras, then the proleptic-year value may be * defined with any appropriate value, although defining it to be the same as ISO may be * the best option. */ YEAR("Year", YEARS, FOREVER, ValueRange.of(Year.MIN_VALUE, Year.MAX_VALUE), "year"), /** * The era. * <p> * This represents the concept of the era, which is the largest division of the time-line. * This field is typically used with {@link #YEAR_OF_ERA}. * <p> * In the default ISO calendar system, there are two eras defined, 'BCE' and 'CE'. * The era 'CE' is the one currently in use and year-of-era runs from 1 to the maximum value. * The era 'BCE' is the previous era, and the year-of-era runs backwards. * See {@link #YEAR_OF_ERA} for a full example. * <p> * Non-ISO calendar systems should implement this field to define eras. * The value of the era that was active on 1970-01-01 (ISO) must be assigned the value 1. * Earlier eras must have sequentially smaller values. * Later eras must have sequentially larger values, */ ERA("Era", ERAS, FOREVER, ValueRange.of(0, 1), "era"), /** * The instant epoch-seconds. * <p> * This represents the concept of the sequential count of seconds where * 1970-01-01T00:00Z (ISO) is zero. * This field may be used with {@link #NANO_OF_SECOND} to represent the fraction of the second. * <p> * An {@link Instant} represents an instantaneous point on the time-line. * On their own, an instant has insufficient information to allow a local date-time to be obtained. * Only when paired with an offset or time-zone can the local date or time be calculated. * <p> * This field is strictly defined to have the same meaning in all calendar systems. * This is necessary to ensure interoperation between calendars. */ INSTANT_SECONDS("InstantSeconds", SECONDS, FOREVER, ValueRange.of(Long.MIN_VALUE, Long.MAX_VALUE)), /** * The offset from UTC/Greenwich. * <p> * This represents the concept of the offset in seconds of local time from UTC/Greenwich. * <p> * A {@link ZoneOffset} represents the period of time that local time differs from UTC/Greenwich. * This is usually a fixed number of hours and minutes. * It is equivalent to the {@link ZoneOffset#getTotalSeconds() total amount} of the offset in seconds. * For example, during the winter Paris has an offset of {@code +01:00}, which is 3600 seconds. * <p> * This field is strictly defined to have the same meaning in all calendar systems. * This is necessary to ensure interoperation between calendars. */ OFFSET_SECONDS("OffsetSeconds", SECONDS, FOREVER, ValueRange.of(-18 * 3600, 18 * 3600)); private final String name; private final TemporalUnit baseUnit; private final TemporalUnit rangeUnit; private final ValueRange range; private final String displayNameKey; private ChronoField(String name, TemporalUnit baseUnit, TemporalUnit rangeUnit, ValueRange range) { this.name = name; this.baseUnit = baseUnit; this.rangeUnit = rangeUnit; this.range = range; this.displayNameKey = null; } private ChronoField(String name, TemporalUnit baseUnit, TemporalUnit rangeUnit, ValueRange range, String displayNameKey) { this.name = name; this.baseUnit = baseUnit; this.rangeUnit = rangeUnit; this.range = range; this.displayNameKey = displayNameKey; } @Override public String getDisplayName(Locale locale) { Objects.requireNonNull(locale, "locale"); if (displayNameKey == null) { return name; } LocaleResources lr = LocaleProviderAdapter.getResourceBundleBased() .getLocaleResources(CalendarDataUtility.findRegionOverride(locale)); ResourceBundle rb = lr.getJavaTimeFormatData(); String key = "field." + displayNameKey; return rb.containsKey(key) ? rb.getString(key) : name; } @Override public TemporalUnit getBaseUnit() { return baseUnit; } @Override public TemporalUnit getRangeUnit() { return rangeUnit; } /** * Gets the range of valid values for the 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> * This method returns the range of the field in the ISO-8601 calendar system. * This range may be incorrect for other calendar systems. * Use {@link Chronology#range(ChronoField)} to access the correct range * for a different calendar system. * <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. * * @return the range of valid values for the field, not null */ @Override public ValueRange range() { return range; } //----------------------------------------------------------------------- /** * Checks if this field represents a component of a date. * <p> * Fields from day-of-week to era are date-based. * * @return true if it is a component of a date */ @Override public boolean isDateBased() { return ordinal() >= DAY_OF_WEEK.ordinal() && ordinal() <= ERA.ordinal(); } /** * Checks if this field represents a component of a time. * <p> * Fields from nano-of-second to am-pm-of-day are time-based. * * @return true if it is a component of a time */ @Override public boolean isTimeBased() { return ordinal() < DAY_OF_WEEK.ordinal(); } //----------------------------------------------------------------------- /** * Checks that the specified value is valid for this field. * <p> * This validates that the value is within the outer range of valid values * returned by {@link #range()}. * <p> * This method checks against the range of the field in the ISO-8601 calendar system. * This range may be incorrect for other calendar systems. * Use {@link Chronology#range(ChronoField)} to access the correct range * for a different calendar system. * * @param value the value to check * @return the value that was passed in */ public long checkValidValue(long value) { return range().checkValidValue(value, this); } /** * Checks that the specified value is valid and fits in an {@code int}. * <p> * This validates that the value is within the outer range of valid values * returned by {@link #range()}. * It also checks that all valid values are within the bounds of an {@code int}. * <p> * This method checks against the range of the field in the ISO-8601 calendar system. * This range may be incorrect for other calendar systems. * Use {@link Chronology#range(ChronoField)} to access the correct range * for a different calendar system. * * @param value the value to check * @return the value that was passed in */ public int checkValidIntValue(long value) { return range().checkValidIntValue(value, this); } //----------------------------------------------------------------------- @Override public boolean isSupportedBy(TemporalAccessor temporal) { return temporal.isSupported(this); } @Override public ValueRange rangeRefinedBy(TemporalAccessor temporal) { return temporal.range(this); } @Override public long getFrom(TemporalAccessor temporal) { return temporal.getLong(this); } @SuppressWarnings("unchecked") @Override public <R extends Temporal> R adjustInto(R temporal, long newValue) { return (R) temporal.with(this, newValue); } //----------------------------------------------------------------------- @Override public String toString() { return name; } }