Module java.base
Package java.time.chrono

Class HijrahChronology

java.lang.Object
java.time.chrono.AbstractChronology
java.time.chrono.HijrahChronology
All Implemented Interfaces:
Serializable, Comparable<Chronology>, Chronology
public final class HijrahChronology extends AbstractChronology implements Serializable
The Hijrah calendar is a lunar calendar supporting Islamic calendars.

The HijrahChronology follows the rules of the Hijrah calendar system. The Hijrah calendar has several variants based on differences in when the new moon is determined to have occurred and where the observation is made. In some variants the length of each month is computed algorithmically from the astronomical data for the moon and earth and in others the length of the month is determined by an authorized sighting of the new moon. For the algorithmically based calendars the calendar can project into the future. For sighting based calendars only historical data from past sightings is available.

The length of each month is 29 or 30 days. Ordinary years have 354 days; leap years have 355 days.

CLDR and LDML identify variants:

Variants of Hijrah Calendars
Chronology ID Calendar Type Locale extension, see Locale Description
Hijrah-umalqura islamic-umalqura ca-islamic-umalqura Islamic - Umm Al-Qura calendar of Saudi Arabia

Additional variants may be available through Chronology.getAvailableChronologies().

Example

Selecting the chronology from the locale uses Chronology.ofLocale(java.util.Locale) to find the Chronology based on Locale supported BCP 47 extension mechanism to request a specific calendar ("ca"). For example, 

      Locale locale = Locale.forLanguageTag("en-US-u-ca-islamic-umalqura");
      Chronology chrono = Chronology.ofLocale(locale);
Implementation Requirements:
This class is immutable and thread-safe.
Implementation Note:
Each Hijrah variant is configured individually. Each variant is defined by a property resource that defines the ID, the calendar type, the start of the calendar, the alignment with the ISO calendar, and the length of each month for a range of years. The variants are loaded by HijrahChronology as a resource from hijrah-config-<calendar type>.properties.

The Hijrah property resource is a set of properties that describe the calendar. The syntax is defined by java.util.Properties#load(Reader).

Configuration of Hijrah Calendar
Property Name Property value Description
id Chronology Id, for example, "Hijrah-umalqura" The Id of the calendar in common usage
type Calendar type, for example, "islamic-umalqura" LDML defines the calendar types
version Version, for example: "1.8.0_1" The version of the Hijrah variant data
iso-start ISO start date, formatted as yyyy-MM-dd, for example: "1900-04-30" The ISO date of the first day of the minimum Hijrah year.
yyyy - a numeric 4 digit year, for example "1434" The value is a sequence of 12 month lengths, for example: "29 30 29 30 29 30 30 30 29 30 29 29" The lengths of the 12 months of the year separated by whitespace. A numeric year property must be present for every year without any gaps. The month lengths must be between 29-32 inclusive.

Additional variants may be added by providing configuration properties files in <JAVA_HOME>/conf/chronology directory. The properties files should follow the naming convention of hijrah-config-<chronology id>_<calendar type>.properties.

Since:
1.8
See Also:
Serialized Form

  • Field Details

  • Method Details

    • getId

      public String getId()
      Gets the ID of the chronology.

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

      Specified by:
      getId in interface Chronology
      Returns:
      the chronology ID, non-null
      See Also:
      getCalendarType()

    • getCalendarType

      public String getCalendarType()
      Gets the calendar type of the Islamic calendar.

      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 Chronology.of(String).

      Specified by:
      getCalendarType in interface Chronology
      Returns:
      the calendar system type; non-null if the calendar has a standard type, otherwise null
      See Also:
      getId()

    • date

      public HijrahDate date​(Era era, int yearOfEra, int month, int dayOfMonth)
      Obtains a local date in Hijrah calendar system from the era, year-of-era, month-of-year and day-of-month fields.
      Specified by:
      date in interface Chronology
      Parameters:
      era - the Hijrah era, not null
      yearOfEra - the year-of-era
      month - the month-of-year
      dayOfMonth - the day-of-month
      Returns:
      the Hijrah local date, not null
      Throws:
      DateTimeException - if unable to create the date
      ClassCastException - if the era is not a HijrahEra

    • date

      public HijrahDate date​(int prolepticYear, int month, int dayOfMonth)
      Obtains a local date in Hijrah calendar system from the proleptic-year, month-of-year and day-of-month fields.
      Specified by:
      date in interface Chronology
      Parameters:
      prolepticYear - the proleptic-year
      month - the month-of-year
      dayOfMonth - the day-of-month
      Returns:
      the Hijrah local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateYearDay

      public HijrahDate dateYearDay​(Era era, int yearOfEra, int dayOfYear)
      Obtains a local date in Hijrah calendar system from the era, year-of-era and day-of-year fields.
      Specified by:
      dateYearDay in interface Chronology
      Parameters:
      era - the Hijrah era, not null
      yearOfEra - the year-of-era
      dayOfYear - the day-of-year
      Returns:
      the Hijrah local date, not null
      Throws:
      DateTimeException - if unable to create the date
      ClassCastException - if the era is not a HijrahEra

    • dateYearDay

      public HijrahDate dateYearDay​(int prolepticYear, int dayOfYear)
      Obtains a local date in Hijrah calendar system from the proleptic-year and day-of-year fields.
      Specified by:
      dateYearDay in interface Chronology
      Parameters:
      prolepticYear - the proleptic-year
      dayOfYear - the day-of-year
      Returns:
      the Hijrah local date, not null
      Throws:
      DateTimeException - if the value of the year is out of range, or if the day-of-year is invalid for the year

    • dateEpochDay

      public HijrahDate dateEpochDay​(long epochDay)
      Obtains a local date in the Hijrah calendar system from the epoch-day.
      Specified by:
      dateEpochDay in interface Chronology
      Parameters:
      epochDay - the epoch day
      Returns:
      the Hijrah local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateNow

      public HijrahDate dateNow()
      Description copied from interface: Chronology
      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.

      Specified by:
      dateNow in interface Chronology
      Returns:
      the current local date using the system clock and default time-zone, not null

    • dateNow

      public HijrahDate dateNow​(ZoneId zone)
      Description copied from interface: Chronology
      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.

      Specified by:
      dateNow in interface Chronology
      Parameters:
      zone - the zone ID to use, not null
      Returns:
      the current local date using the system clock, not null

    • dateNow

      public HijrahDate dateNow​(Clock clock)
      Description copied from interface: Chronology
      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.

      Specified by:
      dateNow in interface Chronology
      Parameters:
      clock - the clock to use, not null
      Returns:
      the current local date, not null

    • date

      public HijrahDate date​(TemporalAccessor temporal)
      Description copied from interface: Chronology
      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.

      Specified by:
      date in interface Chronology
      Parameters:
      temporal - the temporal object to convert, not null
      Returns:
      the local date in this chronology, not null
      See Also:
      ChronoLocalDate.from(TemporalAccessor)

    • localDateTime

      public ChronoLocalDateTime<HijrahDate> localDateTime​(TemporalAccessor temporal)
      Description copied from interface: Chronology
      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.

      Specified by:
      localDateTime in interface Chronology
      Parameters:
      temporal - the temporal object to convert, not null
      Returns:
      the local date-time in this chronology, not null
      See Also:
      ChronoLocalDateTime.from(TemporalAccessor)

    • zonedDateTime

      public ChronoZonedDateTime<HijrahDate> zonedDateTime​(TemporalAccessor temporal)
      Description copied from interface: Chronology
      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.

      Specified by:
      zonedDateTime in interface Chronology
      Parameters:
      temporal - the temporal object to convert, not null
      Returns:
      the zoned date-time in this chronology, not null
      See Also:
      ChronoZonedDateTime.from(TemporalAccessor)

    • zonedDateTime

      public ChronoZonedDateTime<HijrahDate> zonedDateTime​(Instant instant, ZoneId zone)
      Description copied from interface: Chronology
      Obtains a ChronoZonedDateTime in this chronology from an Instant.

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

      Specified by:
      zonedDateTime in interface Chronology
      Parameters:
      instant - the instant to create the date-time from, not null
      zone - the time-zone, not null
      Returns:
      the zoned date-time, not null

    • isLeapYear

      public boolean isLeapYear​(long prolepticYear)
      Description copied from interface: Chronology
      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.

      Specified by:
      isLeapYear in interface Chronology
      Parameters:
      prolepticYear - the proleptic-year to check, not validated for range
      Returns:
      true if the year is a leap year

    • prolepticYear

      public int prolepticYear​(Era era, int yearOfEra)
      Description copied from interface: 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.

      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.

      Specified by:
      prolepticYear in interface Chronology
      Parameters:
      era - the era of the correct type for the chronology, not null
      yearOfEra - the chronology year-of-era
      Returns:
      the proleptic-year

    • eraOf

      public HijrahEra eraOf​(int eraValue)
      Creates the HijrahEra object from the numeric value. The Hijrah calendar system has only one era covering the proleptic years greater than zero. This method returns the singleton HijrahEra for the value 1.
      Specified by:
      eraOf in interface Chronology
      Parameters:
      eraValue - the era value
      Returns:
      the calendar system era, not null
      Throws:
      DateTimeException - if unable to create the era

    • eras

      public List<Era> eras()
      Description copied from interface: 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 interface Chronology
      Returns:
      the list of eras for the chronology, may be immutable, not null

    • range

      public ValueRange range​(ChronoField field)
      Description copied from interface: 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 interface Chronology
      Parameters:
      field - the field to get the range for, not null
      Returns:
      the range of valid values for the field, not null

    • resolveDate

      public HijrahDate resolveDate​(Map<TemporalField,​Long> fieldValues, ResolverStyle resolverStyle)
      Description copied from class: AbstractChronology
      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.

      ChronoField instances are resolved by this method, which may be overridden in subclasses.

      • EPOCH_DAY - If present, this is converted to a date and all other date fields are then cross-checked against the date.
      • PROLEPTIC_MONTH - If present, then it is split into the YEAR and MONTH_OF_YEAR. If the mode is strict or smart then the field is validated.
      • YEAR_OF_ERA and ERA - If both are present, then they are combined to form a YEAR. In lenient mode, the YEAR_OF_ERA range is not validated, in smart and strict mode it is. The ERA is validated for range in all three modes. If only the YEAR_OF_ERA is present, and the mode is smart or lenient, then the last available era is assumed. In strict mode, no era is assumed and the YEAR_OF_ERA is left untouched. If only the ERA is present, then it is left untouched.
      • YEAR, MONTH_OF_YEAR and DAY_OF_MONTH - If all three are present, then they are combined to form a date. In all three modes, the YEAR is validated. If the mode is smart or strict, then the month and day are validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the first month in the requested year, then adding the difference in months, then the difference in days. If the mode is smart, and the day-of-month is greater than the maximum for the year-month, then the day-of-month is adjusted to the last day-of-month. If the mode is strict, then the three fields must form a valid date.
      • YEAR and DAY_OF_YEAR - If both are present, then they are combined to form a date. In all three modes, the YEAR is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the requested year, then adding the difference in days. If the mode is smart or strict, then the two fields must form a valid date.
      • YEAR, MONTH_OF_YEAR, ALIGNED_WEEK_OF_MONTH and ALIGNED_DAY_OF_WEEK_IN_MONTH - If all four are present, then they are combined to form a date. In all three modes, the YEAR is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the first month in the requested year, then adding the difference in months, then the difference in weeks, then in days. If the mode is smart or strict, then the all four fields are validated to their outer ranges. The date is then combined in a manner equivalent to creating a date on the first day of the requested year and month, then adding the amount in weeks and days to reach their values. If the mode is strict, the date is additionally validated to check that the day and week adjustment did not change the month.
      • YEAR, MONTH_OF_YEAR, ALIGNED_WEEK_OF_MONTH and DAY_OF_WEEK - If all four are present, then they are combined to form a date. The approach is the same as described above for years, months and weeks in ALIGNED_DAY_OF_WEEK_IN_MONTH. The day-of-week is adjusted as the next or same matching day-of-week once the years, months and weeks have been handled.
      • YEAR, ALIGNED_WEEK_OF_YEAR and ALIGNED_DAY_OF_WEEK_IN_YEAR - If all three are present, then they are combined to form a date. In all three modes, the YEAR is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the requested year, then adding the difference in weeks, then in days. If the mode is smart or strict, then the all three fields are validated to their outer ranges. The date is then combined in a manner equivalent to creating a date on the first day of the requested year, then adding the amount in weeks and days to reach their values. If the mode is strict, the date is additionally validated to check that the day and week adjustment did not change the year.
      • YEAR, ALIGNED_WEEK_OF_YEAR and DAY_OF_WEEK - If all three are present, then they are combined to form a date. The approach is the same as described above for years and weeks in ALIGNED_DAY_OF_WEEK_IN_YEAR. The day-of-week is adjusted as the next or same matching day-of-week once the years and weeks have been handled.

      The default implementation is suitable for most calendar systems. If ChronoField.YEAR_OF_ERA is found without an ChronoField.ERA then the last era in Chronology.eras() is used. The implementation assumes a 7 day week, that the first day-of-month has the value 1, that first day-of-year has the value 1, and that the first of the month and year always exists.

      Specified by:
      resolveDate in interface Chronology
      Overrides:
      resolveDate in class AbstractChronology
      Parameters:
      fieldValues - the map of fields to values, which can be updated, not null
      resolverStyle - the requested type of resolve, not null
      Returns:
      the resolved date, null if insufficient information to create a date