Obtains a local date in this chronology from another temporal object.
Obtains a local date in this chronology from another temporal object.
This creates a date in this chronology based on the specified TemporalAccessor
.
The standard mechanism for conversion between date types is the
ChronoField#EPOCH_DAY local epoch-day
field.
the temporal object to convert, not null
the local date in this chronology, not null
if unable to create the date
Obtains a local date in this chronology from the proleptic-year, month-of-year and day-of-month fields.
Obtains a local date in this chronology from the proleptic-year, month-of-year and day-of-month fields.
the chronology proleptic-year
the chronology month-of-year
the chronology day-of-month
the local date in this chronology, not null
if unable to create the date
Obtains a local date in this chronology from the epoch-day.
Obtains a local date in this chronology from the epoch-day.
The definition of ChronoField#EPOCH_DAY EPOCH_DAY
is the same
for all calendar systems, thus it can be used for conversion.
the epoch day
the local date in this chronology, not null
if unable to create the date
Obtains a local date in this chronology from the proleptic-year and day-of-year fields.
Obtains a local date in this chronology from the proleptic-year and day-of-year fields.
the chronology proleptic-year
the chronology day-of-year
the local date in this chronology, not null
if unable to create the date
Creates the chronology era object from the numeric value.
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.
the era value
the calendar system era, not null
if unable to create the era
Gets the list of eras for the 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.
the list of eras for the chronology, may be immutable, not null
Gets the calendar type of the underlying calendar system.
Gets the calendar type of the underlying calendar system.
The calendar type is an identifier defined by the
Unicode Locale Data Markup Language (LDML) specification.
It can be used to lookup the Chronology
using #of(String)
.
It can also be used as part of a locale, accessible via
Locale#getUnicodeLocaleType(String)
with the key 'ca'.
the calendar system type, null if the calendar is not defined by LDML
#getId()
Gets the ID of the chronology.
Gets the ID of the chronology.
The ID uniquely identifies the Chronology
.
It can be used to lookup the Chronology
using #of(String)
.
the chronology ID, not null
#getCalendarType()
Checks if the specified year is a leap year.
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.
the proleptic-year to check, not validated for range
true if the year is a leap year
Calculates the proleptic-year given the era and year-of-era.
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.
the era of the correct type for the chronology, not null
the chronology year-of-era
the proleptic-year
if the { @code era} is not of the correct type for the chronology
DateTimeExceptionif unable to convert
Gets the range of valid values for the specified 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.
the field to get the range for, not null
the range of valid values for the field, not null
if the range for the field cannot be obtained
Resolves parsed ChronoField
values into a date during parsing.
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
.
the map of fields to values, which can be updated, not null
the requested type of resolve, not null
the resolved date, null if insufficient information to create a date
if the date cannot be resolved, typically because of a conflict in the input data
Compares this chronology to another chronology.
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
.
The default implementation compares the chronology ID. Subclasses must compare any additional state that they store.
the other chronology to compare to, not null
the comparator value, negative if less, positive if greater
Obtains a local date in this chronology from the era, year-of-era, month-of-year and day-of-month fields.
Obtains a local date in this chronology from the era, year-of-era, month-of-year and day-of-month fields.
the era of the correct type for the chronology, not null
the chronology year-of-era
the chronology month-of-year
the chronology day-of-month
the local date in this chronology, not null
if the { @code era} is not of the correct type for the chronology
DateTimeExceptionif unable to create the date
Obtains the current local date in this chronology from the specified 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 Clock dependency injection
.
the clock to use, not null
the current local date, not null
if unable to create the date
Obtains the current local date in this chronology from the system clock in the specified time-zone.
Obtains the current local date in this chronology from the system clock in the specified time-zone.
This will query the Clock#system(ZoneId) 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.
the zone ID to use, not null
the current local date using the system clock, not null
if unable to create the date
Obtains the current local date in this chronology from the system clock in the default time-zone.
Obtains the current local date in this chronology from the system clock in the default time-zone.
This will query the Clock#systemDefaultZone() 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.
This implementation uses #dateNow(Clock)
.
the current local date using the system clock and default time-zone, not null
if unable to create the date
Obtains a local date in this chronology from the era, year-of-era and day-of-year fields.
Obtains a local date in this chronology from the era, year-of-era and day-of-year fields.
the era of the correct type for the chronology, not null
the chronology year-of-era
the chronology day-of-year
the local date in this chronology, not null
if the { @code era} is not of the correct type for the chronology
DateTimeExceptionif unable to create the date
Checks if this chronology is equal to another chronology.
Checks if this chronology is equal to another chronology.
The comparison is based on the entire state of the object.
The default implementation checks the type and calls #compareTo(Chronology)
.
the object to check, null returns false
true if this is equal to the other chronology
Gets the textual representation of this chronology.
Gets the textual representation of this chronology.
This returns the textual name used to identify the chronology. The parameters control the style of the returned text and the locale.
the style of the text required, not null
the locale to use, not null
the text value of the chronology, not null
A hash code for this chronology.
A hash code for this chronology.
The default implementation is based on the ID and class. Subclasses should add any additional state that they store.
a suitable hash code
Obtains a local date-time in this chronology from another temporal object.
Obtains a local date-time in this chronology from another temporal object.
This creates a date-time in this chronology based on the specified TemporalAccessor
.
The date of the date-time should be equivalent to that obtained by calling
#date(TemporalAccessor)
.
The standard mechanism for conversion between time types is the
ChronoField#NANO_OF_DAY nano-of-day
field.
the temporal object to convert, not null
the local date-time in this chronology, not null
if unable to create the date-time
Obtains a period for this chronology based on years, months and 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.
The default implementation returns an implementation class suitable
for most calendar systems. It is based solely on the three units.
Normalization, addition and subtraction derive the number of months
in a year from the #range(ChronoField)
. If the number of
months within a year is fixed, then the calculation approach for
addition, subtraction and normalization is slightly different.
If implementing an unusual calendar system that is not based on
years, months and days, or where you want direct control, then
the ChronoPeriod
interface must be directly implemented.
The returned period is immutable and thread-safe.
the number of years, may be negative
the number of years, may be negative
the number of years, may be negative
the period in terms of this chronology, not null
Outputs this chronology as a String
, using the ID.
Outputs this chronology as a String
, using the ID.
a string representation of this chronology, not null
Obtains a zoned date-time in this chronology from an Instant
.
Obtains a zoned date-time in this chronology from an Instant
.
This creates a zoned date-time with the same instant as that specified.
the instant to create the date-time from, not null
the time-zone, not null
the zoned date-time, not null
if the result exceeds the supported range
Obtains a zoned date-time in this chronology from another temporal object.
Obtains a zoned date-time in this chronology from another temporal object.
This creates a date-time in this chronology based on the specified TemporalAccessor
.
This should obtain a ZoneId
using ZoneId#from(TemporalAccessor)
.
The date-time should be obtained by obtaining an Instant
.
If that fails, the local date-time should be used.
the temporal object to convert, not null
the zoned date-time in this chronology, not null
if unable to create the date-time
A calendar system, used to organize and identify dates.
The main date and time API is built on the ISO calendar system. This class operates behind the scenes to represent the general concept of a calendar system. For example, the Japanese, Minguo, Thai Buddhist and others.
Most other calendar systems also operate on the shared concepts of year, month and day, linked to the cycles of the Earth around the Sun, and the Moon around the Earth. These shared concepts are defined by
ChronoField
and are availalbe for use by anyChronology
implementation:As shown, although the date objects are in different calendar systems, represented by different
Chronology
instances, both can be queried using the same constant onChronoField
. For a full discussion of the implications of this, seeChronoLocalDate
. In general, the advice is to use the known ISO-basedLocalDate
, rather thanChronoLocalDate
.While a
Chronology
object typically usesChronoField
and is based on an era, year-of-era, month-of-year, day-of-month model of a date, this is not required. AChronology
instance may represent a totally different kind of calendar system, such as the Mayan.In practical terms, the
Chronology
instance also acts as a factory. The#of(String)
method allows an instance to be looked up by identifier, while the#ofLocale(Locale)
method allows lookup by locale.The
Chronology
instance provides a set of methods to createChronoLocalDate
instances. The date classes are used to manipulate specific dates.#dateNow() dateNow()
#dateNow(Clock) dateNow(clock)
#dateNow(ZoneId) dateNow(zone)
#date(int, int, int) date(yearProleptic, month, day)
#date(Era, int, int, int) date(era, yearOfEra, month, day)
#dateYearDay(int, int) dateYearDay(yearProleptic, dayOfYear)
#dateYearDay(Era, int, int) dateYearDay(era, yearOfEra, dayOfYear)
#date(TemporalAccessor) date(TemporalAccessor)
Adding New Calendars The set of available chronologies can be extended by applications. Adding a new calendar system requires the writing of an implementation of
Chronology
,ChronoLocalDate
andEra
. The majority of the logic specific to the calendar system will be inChronoLocalDate
. TheChronology
subclass acts as a factory.To permit the discovery of additional chronologies, the
java.util.ServiceLoader ServiceLoader
is used. A file must be added to theMETA-INF/services
directory with the name 'org.threeten.bp.chrono.Chrono' listing the implementation classes. See the ServiceLoader for more details on service loading. For lookup by id or calendarType, the system provided calendars are found first followed by application provided calendars.Each chronology must define a chronology ID that is unique within the system. If the chronology represents a calendar system defined by the Unicode Locale Data Markup Language (LDML) specification then that calendar type should also be specified.
Specification for implementors
This class must be implemented with care to ensure other classes operate correctly. All implementations that can be instantiated must be final, immutable and thread-safe. Subclasses should be Serializable wherever possible.