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/*
* 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
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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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.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.
*/
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.
*/
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()}.
*/
HOUR_OF_DAY("HourOfDay", HOURS, DAYS, ValueRange.of(0, 23), "hour"),
/**
* The clock-hour-of-day.
* <p>
* This counts the hour within the AM/PM, 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.
*/
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.
*/
EPOCH_DAY("EpochDay", DAYS, FOREVER, ValueRange.of((long) (Year.MIN_VALUE * 365.25), (long) (Year.MAX_VALUE * 365.25))),
/**
* 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(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>
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