PaxChronology.java
/*
* Copyright (c) 2007-present, Stephen Colebourne & Michael Nascimento Santos
*
* All rights reserved.
*
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* modification, are permitted provided that the following conditions are met:
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* * Neither the name of JSR-310 nor the names of its contributors
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package org.threeten.extra.chrono;
import java.io.Serializable;
import java.time.Clock;
import java.time.DateTimeException;
import java.time.Instant;
import java.time.ZoneId;
import java.time.chrono.AbstractChronology;
import java.time.chrono.ChronoLocalDateTime;
import java.time.chrono.ChronoZonedDateTime;
import java.time.chrono.Chronology;
import java.time.chrono.Era;
import java.time.format.ResolverStyle;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalField;
import java.time.temporal.ValueRange;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
/**
* The Pax calendar system.
* <p>
* This chronology defines the rules of the proleptic Pax calendar system.
* This calendar system is a proposed reform calendar system, and is not in common use.
* The Pax differs from the Gregorian in terms of month count and length, and the leap year rule.
* Dates are aligned such that {@code 0001-01-01 (Pax)} is {@code 0000-12-31 (ISO)}.
* <p>
* This class is proleptic. It implements Pax rules to the entire time-line.
* <p>
* The fields are defined as follows:
* <ul>
* <li>era - There are two eras, the current 'Current Era' (CE) and the previous era 'Before Current Era' (BCE).
* <li>year-of-era - The year-of-era for the current era increases uniformly from the epoch at year one.
* For the previous era the year increases from one as time goes backwards.
* <li>proleptic-year - The proleptic year is the same as the year-of-era for the
* current era. For the previous era, years have zero, then negative values.
* <li>month-of-year - There are 13 or 14 months in a Pax year, numbered from 1 to 13 (or 14).
* <li>day-of-month - There are 28 days in each Pax month, numbered from 1 to 28.
* In a leap year a one-week month ('Pax') is inserted between months 12 and 13, shifting 13 to 14.
* <li>day-of-year - There are 364 days in a standard Pax year and 371 in a leap year.
* The days are numbered from 1 to 364 or 1 to 371.
* <li>leap-year - Leap years occur in every year whose last two digits are divisible by {@code 6}, are {@code 99}, or are {@code 00} and the year is <b>not</b> divisible by 400.
* </ul>
* <p>
* For more information, please read the <a href="https://en.wikipedia.org/wiki/Pax_Calendar">Pax Calendar</a> Wikipedia article.
*
* <h3>Implementation Requirements</h3>
* This class is immutable and thread-safe.
*/
public final class PaxChronology extends AbstractChronology implements Serializable {
/**
* Singleton instance for the Pax chronology.
*/
public static final PaxChronology INSTANCE = new PaxChronology();
/**
* Serialization version.
*/
private static final long serialVersionUID = -7021464635577802085L;
/**
* The leap-month of Pax is only one week long.
*/
static final int WEEKS_IN_LEAP_MONTH = 1;
/**
* Standard 7-day week.
*/
static final int DAYS_IN_WEEK = 7;
/**
* In all months (except Pax), there are 4 complete weeks.
*/
static final int WEEKS_IN_MONTH = 4;
/**
* There are 13 months in a (non-leap) year.
*/
static final int MONTHS_IN_YEAR = 13;
/**
* There are 4 weeks of 7 days, or 28 total days in a month.
*/
static final int DAYS_IN_MONTH = WEEKS_IN_MONTH * DAYS_IN_WEEK;
/**
* There are 13 months of 28 days, or 364 days in a (non-leap) year.
*/
static final int DAYS_IN_YEAR = MONTHS_IN_YEAR * DAYS_IN_MONTH;
/**
* There are 52 weeks in a (non-leap) year.
*/
static final int WEEKS_IN_YEAR = DAYS_IN_YEAR / DAYS_IN_WEEK;
/**
* Range of aligned week of month.
*/
static final ValueRange ALIGNED_WEEK_OF_MONTH_RANGE = ValueRange.of(1, WEEKS_IN_LEAP_MONTH, WEEKS_IN_MONTH);
/**
* Range of aligned week of year.
*/
static final ValueRange ALIGNED_WEEK_OF_YEAR_RANGE = ValueRange.of(1, WEEKS_IN_YEAR, WEEKS_IN_YEAR + 1);
/**
* Range of day of month.
*/
static final ValueRange DAY_OF_MONTH_RANGE = ValueRange.of(1, DAYS_IN_WEEK, DAYS_IN_MONTH);
/**
* Range of day of year.
*/
static final ValueRange DAY_OF_YEAR_RANGE = ValueRange.of(1, DAYS_IN_YEAR, DAYS_IN_YEAR + DAYS_IN_WEEK);
/**
* Range of month of year.
*/
static final ValueRange MONTH_OF_YEAR_RANGE = ValueRange.of(1, MONTHS_IN_YEAR, MONTHS_IN_YEAR + 1);
/**
* Private constructor, that is public to satisfy the {@code ServiceLoader}.
* @deprecated Use the singleton {@link #INSTANCE} instead.
*/
@Deprecated
public PaxChronology() {
}
/**
* Resolve singleton.
*
* @return the singleton instance, not null
*/
@SuppressWarnings("static-method")
private Object readResolve() {
return INSTANCE;
}
//-----------------------------------------------------------------------
/**
* Gets the ID of the chronology - 'Pax'.
* <p>
* The ID uniquely identifies the {@code Chronology}.
* It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
*
* @return the chronology ID - 'Pax'
* @see #getCalendarType()
*/
@Override
public String getId() {
return "Pax";
}
/**
* Gets the calendar type of the underlying calendar system - 'pax'.
* <p>
* The <em>Unicode Locale Data Markup Language (LDML)</em> specification
* does not define an identifier for the Pax calendar, but were it to
* do so, 'pax' is highly likely to be chosen.
*
* @return the calendar system type - 'pax'
* @see #getId()
*/
@Override
public String getCalendarType() {
return "pax";
}
//-----------------------------------------------------------------------
/**
* Obtains a local date in Pax calendar system from the
* era, year-of-era, month-of-year and day-of-month fields.
*
* @param era the Pax era, not null
* @param yearOfEra the year-of-era
* @param month the month-of-year
* @param dayOfMonth the day-of-month
* @return the Pax local date, not null
* @throws DateTimeException if unable to create the date
* @throws ClassCastException if the {@code era} is not a {@code PaxEra}
*/
@Override
public PaxDate date(Era era, int yearOfEra, int month, int dayOfMonth) {
return date(prolepticYear(era, yearOfEra), month, dayOfMonth);
}
/**
* Obtains a local date in Pax calendar system from the
* proleptic-year, month-of-year and day-of-month fields.
*
* @param prolepticYear the proleptic-year
* @param month the month-of-year
* @param dayOfMonth the day-of-month
* @return the Pax local date, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate date(int prolepticYear, int month, int dayOfMonth) {
return PaxDate.of(prolepticYear, month, dayOfMonth);
}
/**
* Obtains a local date in Pax calendar system from the
* era, year-of-era and day-of-year fields.
*
* @param era the Pax era, not null
* @param yearOfEra the year-of-era
* @param dayOfYear the day-of-year
* @return the Pax local date, not null
* @throws DateTimeException if unable to create the date
* @throws ClassCastException if the {@code era} is not a {@code PaxEra}
*/
@Override
public PaxDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {
return dateYearDay(prolepticYear(era, yearOfEra), dayOfYear);
}
/**
* Obtains a local date in Pax calendar system from the
* proleptic-year and day-of-year fields.
*
* @param prolepticYear the proleptic-year
* @param dayOfYear the day-of-year
* @return the Pax local date, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate dateYearDay(int prolepticYear, int dayOfYear) {
return PaxDate.ofYearDay(prolepticYear, dayOfYear);
}
/**
* Obtains a local date in the Pax calendar system from the epoch-day.
*
* @param epochDay the epoch day
* @return the Pax local date, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate dateEpochDay(long epochDay) {
return PaxDate.ofEpochDay(epochDay);
}
//-------------------------------------------------------------------------
/**
* Obtains the current Pax local date 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.
*
* @return the current Pax local date using the system clock and default time-zone, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate dateNow() {
return PaxDate.now();
}
/**
* Obtains the current Pax local date 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.
*
* @param zone the ZoneId to use, not null
* @return the current Pax local date using the system clock, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate dateNow(ZoneId zone) {
return PaxDate.now(zone);
}
/**
* Obtains the current Pax local date 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}.
*
* @param clock the clock to use, not null
* @return the current Pax local date, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate dateNow(Clock clock) {
return PaxDate.now(clock);
}
//-------------------------------------------------------------------------
/**
* Obtains a Pax local date from another date-time object.
*
* @param temporal the date-time object to convert, not null
* @return the Pax local date, not null
* @throws DateTimeException if unable to create the date
*/
@Override
public PaxDate date(TemporalAccessor temporal) {
return PaxDate.from(temporal);
}
/**
* Obtains a Pax local date-time from another date-time object.
*
* @param temporal the date-time object to convert, not null
* @return the Pax local date-time, not null
* @throws DateTimeException if unable to create the date-time
*/
@Override
@SuppressWarnings("unchecked")
public ChronoLocalDateTime<PaxDate> localDateTime(TemporalAccessor temporal) {
return (ChronoLocalDateTime<PaxDate>) super.localDateTime(temporal);
}
/**
* Obtains a Pax zoned date-time from another date-time object.
*
* @param temporal the date-time object to convert, not null
* @return the Pax zoned date-time, not null
* @throws DateTimeException if unable to create the date-time
*/
@Override
@SuppressWarnings("unchecked")
public ChronoZonedDateTime<PaxDate> zonedDateTime(TemporalAccessor temporal) {
return (ChronoZonedDateTime<PaxDate>) super.zonedDateTime(temporal);
}
/**
* Obtains a Pax zoned date-time in this chronology from an {@code Instant}.
*
* @param instant the instant to create the date-time from, not null
* @param zone the time-zone, not null
* @return the Pax zoned date-time, not null
* @throws DateTimeException if the result exceeds the supported range
*/
@Override
@SuppressWarnings("unchecked")
public ChronoZonedDateTime<PaxDate> zonedDateTime(Instant instant, ZoneId zone) {
return (ChronoZonedDateTime<PaxDate>) super.zonedDateTime(instant, zone);
}
//-----------------------------------------------------------------------
/**
* Checks if the specified year is a leap year.
* <p>
* In general, a year is a leap year if the last two digits are divisible by 6 without remainder, or are 99.
* Years with the last two digits of 00 are also leap years, with the exception of years divisible by 400, which are not.
* <p>
* For example, 2012 is a leap year because the last two digits (12) are divisible by 6.
* 1999 is a leap year as the last two digits are both 9's (99).
* 1900 is a leap year as the last two digits are both 0's (00), however 2000 was not a leap year as it is divisible by 400.
* The year 0 is not a leap year.
*
* @param prolepticYear the proleptic-year to check, not validated for range
* @return true if the year is a leap year
*/
@Override
public boolean isLeapYear(long prolepticYear) {
long lastTwoDigits = prolepticYear % 100;
return Math.abs(lastTwoDigits) == 99 || (prolepticYear % 400 != 0 && (lastTwoDigits == 0 || lastTwoDigits % 6 == 0));
}
@Override
public int prolepticYear(Era era, int yearOfEra) {
if (!(era instanceof PaxEra)) {
throw new ClassCastException("Era must be PaxEra");
}
return (era == PaxEra.CE ? yearOfEra : 1 - yearOfEra);
}
@Override
public PaxEra eraOf(int eraValue) {
return PaxEra.of(eraValue);
}
@Override
public List<Era> eras() {
return Arrays.<Era>asList(PaxEra.values());
}
//-----------------------------------------------------------------------
@Override
public ValueRange range(ChronoField field) {
switch (field) {
case ALIGNED_WEEK_OF_MONTH:
return ALIGNED_WEEK_OF_MONTH_RANGE;
case ALIGNED_WEEK_OF_YEAR:
return ALIGNED_WEEK_OF_YEAR_RANGE;
case DAY_OF_MONTH:
return DAY_OF_MONTH_RANGE;
case DAY_OF_YEAR:
return DAY_OF_YEAR_RANGE;
case MONTH_OF_YEAR:
return MONTH_OF_YEAR_RANGE;
default:
return field.range();
}
}
//-----------------------------------------------------------------------
@Override
public PaxDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
return (PaxDate) super.resolveDate(fieldValues, resolverStyle);
}
}