Class IsoChronology
- All Implemented Interfaces:
Serializable
,Comparable<Chronology>
This chronology defines the rules of the ISO calendar system. This calendar system is based on the ISO-8601 standard, which is the de facto world calendar.
The fields are defined as follows:
- era - There are two eras, 'Current Era' (CE) and 'Before Current Era' (BCE).
- year-of-era - The year-of-era is the same as the proleptic-year for the current CE era. For the BCE era before the ISO epoch the year increases from 1 upwards as time goes backwards.
- 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.
- month-of-year - There are 12 months in an ISO year, numbered from 1 to 12.
- day-of-month - There are between 28 and 31 days in each of the ISO month, numbered from 1 to 31. Months 4, 6, 9 and 11 have 30 days, Months 1, 3, 5, 7, 8, 10 and 12 have 31 days. Month 2 has 28 days, or 29 in a leap year.
- day-of-year - There are 365 days in a standard ISO year and 366 in a leap year. The days are numbered from 1 to 365 or 1 to 366.
- leap-year - Leap years occur every 4 years, except where the year is divisble by 100 and not divisble by 400.
Specification for implementors
This class is immutable and thread-safe.- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final IsoChronology
Singleton instance of the ISO chronology. -
Method Summary
Modifier and TypeMethodDescriptiondate
(int prolepticYear, int month, int dayOfMonth) Obtains an ISO local date from the proleptic-year, month-of-year and day-of-month fields.Obtains an ISO local date from the era, year-of-era, month-of-year and day-of-month fields.date
(TemporalAccessor temporal) Obtains an ISO local date from another date-time object.dateEpochDay
(long epochDay) Obtains a local date in this chronology from the epoch-day.dateNow()
Obtains the current ISO local date from the system clock in the default time-zone.Obtains the current ISO local date from the specified clock.Obtains the current ISO local date from the system clock in the specified time-zone.dateYearDay
(int prolepticYear, int dayOfYear) Obtains an ISO local date from the proleptic-year and day-of-year fields.dateYearDay
(Era era, int yearOfEra, int dayOfYear) Obtains an ISO local date from the era, year-of-era and day-of-year fields.eraOf
(int eraValue) Creates the chronology era object from the numeric value.eras()
Gets the list of eras for the chronology.Gets the calendar type of the underlying calendar system - 'iso8601'.getId()
Gets the ID of the chronology - 'ISO'.boolean
isLeapYear
(long prolepticYear) Checks if the year is a leap year, according to the ISO proleptic calendar system rules.localDateTime
(TemporalAccessor temporal) Obtains an ISO local date-time from another date-time object.int
prolepticYear
(Era era, int yearOfEra) Calculates the proleptic-year given the era and year-of-era.range
(ChronoField field) Gets the range of valid values for the specified field.resolveDate
(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) Resolves parsedChronoField
values into a date during parsing.zonedDateTime
(Instant instant, ZoneId zone) Obtains an ISO zoned date-time from an instant.zonedDateTime
(TemporalAccessor temporal) Obtains an ISO zoned date-time from another date-time object.Methods inherited from class org.threeten.bp.chrono.Chronology
compareTo, equals, from, getAvailableChronologies, getDisplayName, hashCode, of, ofLocale, period, toString
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Field Details
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INSTANCE
Singleton instance of the ISO chronology.
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Method Details
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getId
Gets the ID of the chronology - 'ISO'.The ID uniquely identifies the
Chronology
. It can be used to lookup theChronology
usingChronology.of(String)
.- Specified by:
getId
in classChronology
- Returns:
- the chronology ID - 'ISO'
- See Also:
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getCalendarType
Gets the calendar type of the underlying calendar system - 'iso8601'.The calendar type is an identifier defined by the Unicode Locale Data Markup Language (LDML) specification. It can be used to lookup the
Chronology
usingChronology.of(String)
. It can also be used as part of a locale, accessible viaLocale.getUnicodeLocaleType(String)
with the key 'ca'.- Specified by:
getCalendarType
in classChronology
- Returns:
- the calendar system type - 'iso8601'
- See Also:
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date
Obtains an ISO local date from the era, year-of-era, month-of-year and day-of-month fields.- Overrides:
date
in classChronology
- Parameters:
era
- the ISO era, not nullyearOfEra
- the ISO year-of-eramonth
- the ISO month-of-yeardayOfMonth
- the ISO day-of-month- Returns:
- the ISO local date, not null
- Throws:
DateTimeException
- if unable to create the date
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date
Obtains an ISO local date from the proleptic-year, month-of-year and day-of-month fields.This is equivalent to
LocalDate.of(int, int, int)
.- Specified by:
date
in classChronology
- Parameters:
prolepticYear
- the ISO proleptic-yearmonth
- the ISO month-of-yeardayOfMonth
- the ISO day-of-month- Returns:
- the ISO local date, not null
- Throws:
DateTimeException
- if unable to create the date
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dateYearDay
Obtains an ISO local date from the era, year-of-era and day-of-year fields.- Overrides:
dateYearDay
in classChronology
- Parameters:
era
- the ISO era, not nullyearOfEra
- the ISO year-of-eradayOfYear
- the ISO day-of-year- Returns:
- the ISO local date, not null
- Throws:
DateTimeException
- if unable to create the date
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dateYearDay
Obtains an ISO local date from the proleptic-year and day-of-year fields.This is equivalent to
LocalDate.ofYearDay(int, int)
.- Specified by:
dateYearDay
in classChronology
- Parameters:
prolepticYear
- the ISO proleptic-yeardayOfYear
- the ISO day-of-year- Returns:
- the ISO local date, not null
- Throws:
DateTimeException
- if unable to create the date
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dateEpochDay
Description copied from class:Chronology
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.- Specified by:
dateEpochDay
in classChronology
- Parameters:
epochDay
- the epoch day- Returns:
- the local date in this chronology, not null
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date
Obtains an ISO local date from another date-time object.This is equivalent to
LocalDate.from(TemporalAccessor)
.- Specified by:
date
in classChronology
- Parameters:
temporal
- the date-time object to convert, not null- Returns:
- the ISO local date, not null
- Throws:
DateTimeException
- if unable to create the date
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localDateTime
Obtains an ISO local date-time from another date-time object.This is equivalent to
LocalDateTime.from(TemporalAccessor)
.- Overrides:
localDateTime
in classChronology
- Parameters:
temporal
- the date-time object to convert, not null- Returns:
- the ISO local date-time, not null
- Throws:
DateTimeException
- if unable to create the date-time
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zonedDateTime
Obtains an ISO zoned date-time from another date-time object.This is equivalent to
ZonedDateTime.from(TemporalAccessor)
.- Overrides:
zonedDateTime
in classChronology
- Parameters:
temporal
- the date-time object to convert, not null- Returns:
- the ISO zoned date-time, not null
- Throws:
DateTimeException
- if unable to create the date-time
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zonedDateTime
Obtains an ISO zoned date-time from an instant.This is equivalent to
ZonedDateTime.ofInstant(Instant, ZoneId)
.- Overrides:
zonedDateTime
in classChronology
- Parameters:
instant
- the instant to convert, not nullzone
- the zone to use, not null- Returns:
- the ISO zoned date-time, not null
- Throws:
DateTimeException
- if unable to create the date-time
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dateNow
Obtains the current ISO local date 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.
- Overrides:
dateNow
in classChronology
- Returns:
- the current ISO local date using the system clock and default time-zone, not null
- Throws:
DateTimeException
- if unable to create the date
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dateNow
Obtains the current ISO local date 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.
- Overrides:
dateNow
in classChronology
- Parameters:
zone
- the zone ID to use, not null- Returns:
- the current ISO local date using the system clock, not null
- Throws:
DateTimeException
- if unable to create the date
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dateNow
Obtains the current ISO local date 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
.- Overrides:
dateNow
in classChronology
- Parameters:
clock
- the clock to use, not null- Returns:
- the current ISO local date, not null
- Throws:
DateTimeException
- if unable to create the date
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isLeapYear
public boolean isLeapYear(long prolepticYear) Checks if the year is a leap year, according to the ISO proleptic calendar system rules.This method applies the current rules for leap years across the whole time-line. In general, a year is a leap year if it is divisible by four without remainder. However, years divisible by 100, are not leap years, with the exception of years divisible by 400 which are.
For example, 1904 is a leap year it is divisible by 4. 1900 was not a leap year as it is divisible by 100, however 2000 was a leap year as it is divisible by 400.
The calculation is proleptic - applying the same rules into the far future and far past. This is historically inaccurate, but is correct for the ISO-8601 standard.
- Specified by:
isLeapYear
in classChronology
- Parameters:
prolepticYear
- the ISO proleptic year to check- Returns:
- true if the year is leap, false otherwise
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prolepticYear
Description copied from class:Chronology
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.
- Specified by:
prolepticYear
in classChronology
- Parameters:
era
- the era of the correct type for the chronology, not nullyearOfEra
- the chronology year-of-era- Returns:
- the proleptic-year
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eraOf
Description copied from class:Chronology
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.
- Specified by:
eraOf
in classChronology
- Parameters:
eraValue
- the era value- Returns:
- the calendar system era, not null
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eras
Description copied from class:Chronology
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.
- Specified by:
eras
in classChronology
- Returns:
- the list of eras for the chronology, may be immutable, not null
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range
Description copied from class:Chronology
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.
- Specified by:
range
in classChronology
- Parameters:
field
- the field to get the range for, not null- Returns:
- the range of valid values for the field, not null
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resolveDate
Description copied from class:Chronology
Resolves parsedChronoField
values into a date during parsing.Most
TemporalField
implementations are resolved using the resolve method on the field. By contrast, theChronoField
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
.- Specified by:
resolveDate
in classChronology
- Parameters:
fieldValues
- the map of fields to values, which can be updated, not nullresolverStyle
- the requested type of resolve, not null- Returns:
- the resolved date, null if insufficient information to create a date
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