Chronology

compareTo

public abstract int compareTo (Chronology other)

Compares this chronology to another chronology.

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 Comparable.

date

public ChronoLocalDate date (Era era, 
                int yearOfEra, 
                int month, 
                int dayOfMonth)

Obtains a local date in this chronology from the era, year-of-era, month-of-year and day-of-month fields.

date

public abstract ChronoLocalDate date (int prolepticYear, 
                int month, 
                int dayOfMonth)

Obtains a local date in this chronology from the proleptic-year, month-of-year and day-of-month fields.

date

public abstract ChronoLocalDate date (TemporalAccessor temporal)

Obtains a local date in this chronology from another temporal object.

This obtains a date in this chronology based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of ChronoLocalDate.

The conversion typically uses the EPOCH_DAY field, which is standardized across calendar systems.

This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, aChronology::date.

dateEpochDay

public abstract ChronoLocalDate dateEpochDay (long epochDay)

Obtains a local date in this chronology from the epoch-day.

The definition of EPOCH_DAY is the same for all calendar systems, thus it can be used for conversion.

dateNow

public ChronoLocalDate dateNow (Clock clock)

Obtains the current local date in this chronology from the specified clock.

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 dependency injection.

dateNow

public ChronoLocalDate dateNow (ZoneId zone)

Obtains the current local date in this chronology from the system clock in the specified time-zone.

This will query the system clock to obtain the current date. Specifying the time-zone avoids dependence on the default time-zone.

Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

dateNow

public ChronoLocalDate dateNow ()

Obtains the current local date in this chronology from the system clock in the default time-zone.

This will query the system clock in the default time-zone to obtain the current date.

Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

dateYearDay

public ChronoLocalDate dateYearDay (Era era, 
                int yearOfEra, 
                int dayOfYear)

Obtains a local date in this chronology from the era, year-of-era and day-of-year fields.

dateYearDay

public abstract ChronoLocalDate dateYearDay (int prolepticYear, 
                int dayOfYear)

Obtains a local date in this chronology from the proleptic-year and day-of-year fields.

epochSecond

public long epochSecond (int prolepticYear, 
                int month, 
                int dayOfMonth, 
                int hour, 
                int minute, 
                int second, 
                ZoneOffset zoneOffset)

Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z.

The number of seconds is calculated using the proleptic-year, month, day-of-month, hour, minute, second, and zoneOffset.

epochSecond

public long epochSecond (Era era, 
                int yearOfEra, 
                int month, 
                int dayOfMonth, 
                int hour, 
                int minute, 
                int second, 
                ZoneOffset zoneOffset)

Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z.

The number of seconds is calculated using the era, year-of-era, month, day-of-month, hour, minute, second, and zoneOffset.

equals

public abstract boolean equals (Object obj)

Checks if this chronology is equal to another chronology.

The comparison is based on the entire state of the object.

eraOf

public abstract Era eraOf (int eraValue)

Creates the chronology era object from the numeric value.

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.

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.

This method returns the singleton era of the correct type for the specified era value.

eras

public abstract List<Era> eras ()

Gets the list of eras for the chronology.

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.

from

public static Chronology from (TemporalAccessor temporal)

Obtains an instance of Chronology from a temporal object.

This obtains a chronology based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of Chronology.

The conversion will obtain the chronology using TemporalQueries#chronology(). If the specified temporal object does not have a chronology, IsoChronology is returned.

This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, Chronology::from.

getAvailableChronologies

public static Set<Chronology> getAvailableChronologies ()

Returns the available chronologies.

Each returned 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.

getCalendarType

public abstract String getCalendarType ()

Gets the calendar type of the calendar system.

The calendar type is an identifier defined by the CLDR and Unicode Locale Data Markup Language (LDML) specifications to uniquely identify a calendar. The 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 Chronology using of(java.lang.String).

getDisplayName

public String getDisplayName (TextStyle style, 
                Locale locale)

Gets the textual representation of this chronology.

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.

getId

public abstract String getId ()

Gets the ID of the chronology.

The ID uniquely identifies the Chronology. It can be used to lookup the Chronology using of(java.lang.String).

hashCode

public abstract int hashCode ()

A hash code for this chronology.

The hash code should be based on the entire state of the object.

isLeapYear

public abstract boolean isLeapYear (long prolepticYear)

Checks if the specified year is a leap year.

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.

• a leap-year must imply a year-length longer than a non leap-year.
• a chronology that does not support the concept of a year must return false.
• the correct result must be returned for all years within the valid range of years for the chronology.

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.

localDateTime

public ChronoLocalDateTime<? extends ChronoLocalDate> localDateTime (TemporalAccessor temporal)

Obtains a local date-time in this chronology from another temporal object.

This obtains a date-time in this chronology based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of ChronoLocalDateTime.

The conversion extracts and combines the ChronoLocalDate and the 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.

This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, aChronology::localDateTime.

of

public static Chronology of (String id)

Obtains an instance of Chronology from a chronology ID or calendar system type.

This returns a chronology based on either the ID or the type. The chronology ID uniquely identifies the chronology. The calendar system type is defined by the CLDR specification.

The chronology may be a system chronology or a chronology provided by the application via ServiceLoader configuration.

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.

ofLocale

public static Chronology ofLocale (Locale locale)

Obtains an instance of Chronology from a locale.

This returns a Chronology based on the specified locale, typically returning IsoChronology. Other calendar systems are only returned if they are explicitly selected within the locale.

The 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.

The 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.

This method finds the desired calendar system in a manner equivalent to passing "ca" to Locale#getUnicodeLocaleType(String). If the "ca" key is not present, then IsoChronology is returned.

Note that the behavior of this method differs from the older Calendar.getInstance(Locale) method. If that method receives a locale of "th_TH" it will return BuddhistCalendar. By contrast, this method will return 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.

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 Locale to the modern and recommended form of "ja-JP-u-ca-japanese". Thus, there is no difference in behavior between this method and Calendar#getInstance(Locale).

period

public ChronoPeriod period (int years, 
                int months, 
                int days)

Obtains a period for this chronology based on years, months and days.

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 ChronoPeriod API allows the period to be represented using other units.

prolepticYear

public abstract int prolepticYear (Era era, 
                int yearOfEra)

Calculates the proleptic-year given the era and year-of-era.

This combines the era and year-of-era into the single proleptic-year field.

If the chronology makes active use of eras, such as JapaneseChronology then the year-of-era will be validated against the era. For other chronologies, validation is optional.

range

public abstract ValueRange range (ChronoField field)

Gets the range of valid values for the specified field.

All fields can be expressed as a long integer. This method returns an object that describes the valid range for that value.

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.

This method will return a result whether or not the chronology supports the field.

resolveDate

public abstract ChronoLocalDate resolveDate (Map<TemporalField, Long> fieldValues, 
                ResolverStyle resolverStyle)

Resolves parsed ChronoField values into a date during parsing.

Most TemporalField implementations are resolved using the resolve method on the field. By contrast, the ChronoField class defines fields that only have meaning relative to the chronology. As such, ChronoField date fields are resolved here in the context of a specific chronology.

The default implementation, which explains typical resolve behaviour, is provided in AbstractChronology.

toString

public abstract String toString ()

Outputs this chronology as a String.

The format should include the entire state of the object.

zonedDateTime

public ChronoZonedDateTime<? extends ChronoLocalDate> zonedDateTime (Instant instant, 
                ZoneId zone)

Obtains a ChronoZonedDateTime in this chronology from an Instant.

This obtains a zoned date-time with the same instant as that specified.

zonedDateTime

public ChronoZonedDateTime<? extends ChronoLocalDate> zonedDateTime (TemporalAccessor temporal)

Obtains a ChronoZonedDateTime in this chronology from another temporal object.

This obtains a zoned date-time in this chronology based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of ChronoZonedDateTime.

The conversion will first obtain a ZoneId from the temporal object, falling back to a ZoneOffset if necessary. It will then try to obtain an Instant, falling back to a ChronoLocalDateTime if necessary. The result will be either the combination of ZoneId or ZoneOffset with Instant or ChronoLocalDateTime. Implementations are permitted to perform optimizations such as accessing those fields that are equivalent to the relevant objects. The result uses this chronology.

This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, aChronology::zonedDateTime.