Package org.threeten.bp.chrono

Class HijrahDate

  • All Implemented Interfaces:
    Serializable, Comparable<ChronoLocalDate>, Temporal, TemporalAccessor, TemporalAdjuster
    public final class HijrahDate
extends ChronoLocalDate
implements Serializable
    A date in the Hijrah calendar system.

    This implements ChronoLocalDate for the Hijrah calendar.

    The Hijrah calendar has a different total of days in a year than Gregorian calendar, and a month is based on the period of a complete revolution of the moon around the earth (as between successive new moons). The calendar cycles becomes longer and unstable, and sometimes a manual adjustment (for entering deviation) is necessary for correctness because of the complex algorithm.

    HijrahDate supports the manual adjustment feature by providing a configuration file. The configuration file contains the adjustment (deviation) data with following format. 

       StartYear/StartMonth(0-based)-EndYear/EndMonth(0-based):Deviation day (1, 2, -1, or -2)
   Line separator or ";" is used for the separator of each deviation data.
    Here is the example. 
         1429/0-1429/1:1
     1429/2-1429/7:1;1429/6-1429/11:1
     1429/11-9999/11:1
    The default location of the configuration file is: 
       $CLASSPATH/org/threeten/bp/chrono
    And the default file name is: 
       hijrah_deviation.cfg
    The default location and file name can be overriden by setting following two Java's system property. 
       Location: org.threeten.bp.i18n.HijrahDate.deviationConfigDir
   File name: org.threeten.bp.i18n.HijrahDate.deviationConfigFile

    Specification for implementors

    This class is immutable and thread-safe.
    See Also:
    Serialized Form

    • Field Detail

      • MIN_VALUE_OF_ERA

        public static final int MIN_VALUE_OF_ERA
        The minimum valid year-of-era.
        See Also:
        Constant Field Values

      • MAX_VALUE_OF_ERA

        public static final int MAX_VALUE_OF_ERA
        The maximum valid year-of-era. This is currently set to 9999 but may be changed to increase the valid range in a future version of the specification.
        See Also:
        Constant Field Values

    • Method Detail

      • now

        public static HijrahDate now()
        Obtains the current HijrahDate of the Islamic Umm Al-Qura calendar 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.

        Returns:
        the current date using the system clock and default time-zone, not null

      • now

        public static HijrahDate now​(ZoneId zone)
        Obtains the current HijrahDate of the Islamic Umm Al-Qura calendar 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.

        Parameters:
        zone - the zone ID to use, not null
        Returns:
        the current date using the system clock, not null

      • now

        public static HijrahDate now​(Clock clock)
        Obtains the current HijrahDate of the Islamic Umm Al-Qura calendar 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.

        Parameters:
        clock - the clock to use, not null
        Returns:
        the current date, not null
        Throws:
        DateTimeException - if the current date cannot be obtained

      • of

        public static HijrahDate of​(int prolepticYear,
                            int monthOfYear,
                            int dayOfMonth)
        Obtains an instance of HijrahDate from the Hijrah era year, month-of-year and day-of-month. This uses the Hijrah era.
        Parameters:
        prolepticYear - the proleptic year to represent in the Hijrah
        monthOfYear - the month-of-year to represent, from 1 to 12
        dayOfMonth - the day-of-month to represent, from 1 to 30
        Returns:
        the Hijrah date, never null
        Throws:
        IllegalCalendarFieldValueException - if the value of any field is out of range
        InvalidCalendarFieldException - if the day-of-month is invalid for the month-year

      • from

        public static HijrahDate from​(TemporalAccessor temporal)
        Obtains a HijrahDate of the Islamic Umm Al-Qura calendar from a temporal object.

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

        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, HijrahDate::from.

        Parameters:
        temporal - the temporal object to convert, not null
        Returns:
        the date in Hijrah calendar system, not null
        Throws:
        DateTimeException - if unable to convert to a HijrahDate

      • getChronology

        public HijrahChronology getChronology()
        Description copied from class: ChronoLocalDate
        Gets the chronology of this date.

        The Chronology represents the calendar system in use. The era and other fields in ChronoField are defined by the chronology.

        Specified by:
        getChronology in class ChronoLocalDate
        Returns:
        the chronology, not null

      • getEra

        public HijrahEra getEra()
        Description copied from class: ChronoLocalDate
        Gets the era, as defined by the chronology.

        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.

        All correctly implemented Era classes are singletons, thus it is valid code to write date.getEra() == SomeEra.NAME).

        Overrides:
        getEra in class ChronoLocalDate
        Returns:
        the chronology specific era constant applicable at this date, not null

      • range

        public ValueRange range​(TemporalField field)
        Description copied from interface: TemporalAccessor
        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. The value of this temporal object is used to enhance the accuracy of the returned range. If the date-time cannot return the range, because the field is unsupported or for some other reason, an exception will be thrown.

        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.

        Specification for implementors

        Implementations must check and handle all fields defined in ChronoField. If the field is supported, then the range of the field must be returned. If unsupported, then a DateTimeException must be thrown.

        If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessorl) passing this as the argument.

        Implementations must not alter either this object.

        Specified by:
        range in interface TemporalAccessor
        Overrides:
        range in class DefaultInterfaceTemporalAccessor
        Parameters:
        field - the field to query the range for, not null
        Returns:
        the range of valid values for the field, not null

      • getLong

        public long getLong​(TemporalField field)
        Description copied from interface: TemporalAccessor
        Gets the value of the specified field as a long.

        This queries the date-time for the value for the specified field. The returned value may be outside the valid range of values for the field. If the date-time cannot return the value, because the field is unsupported or for some other reason, an exception will be thrown.

        Specification for implementors

        Implementations must check and handle all fields defined in ChronoField. If the field is supported, then the value of the field must be returned. If unsupported, then a DateTimeException must be thrown.

        If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument.

        Implementations must not alter either this object.

        Specified by:
        getLong in interface TemporalAccessor
        Parameters:
        field - the field to get, not null
        Returns:
        the value for the field

      • with

        public HijrahDate with​(TemporalAdjuster adjuster)
        Description copied from interface: Temporal
        Returns an adjusted object of the same type as this object with the adjustment made.

        This adjusts this date-time according to the rules of the specified adjuster. A simple adjuster might simply set the one of the fields, such as the year field. A more complex adjuster might set the date to the last day of the month. A selection of common adjustments is provided in TemporalAdjusters. These include finding the "last day of the month" and "next Wednesday". The adjuster is responsible for handling special cases, such as the varying lengths of month and leap years.

        Some example code indicating how and why this method is used: 

          date = date.with(Month.JULY);        // most key classes implement TemporalAdjuster
  date = date.with(lastDayOfMonth());  // static import from TemporalAdjusters
  date = date.with(next(WEDNESDAY));   // static import from TemporalAdjusters and DayOfWeek

        Specification for implementors

        Implementations must not alter either this object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
        Specified by:
        with in interface Temporal
        Overrides:
        with in class ChronoLocalDate
        Parameters:
        adjuster - the adjuster to use, not null
        Returns:
        an object of the same type with the specified adjustment made, not null

      • with

        public HijrahDate with​(TemporalField field,
                       long newValue)
        Description copied from interface: Temporal
        Returns an object of the same type as this object with the specified field altered.

        This returns a new object based on this one with the value for the specified field changed. For example, on a LocalDate, this could be used to set the year, month or day-of-month. The returned object will have the same observable type as this object.

        In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st January, then changing the month to February would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

        Specification for implementors

        Implementations must check and handle all fields defined in ChronoField. If the field is supported, then the adjustment must be performed. If unsupported, then a DateTimeException must be thrown.

        If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.adjustInto(Temporal, long) passing this as the first argument.

        Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

        Specified by:
        with in interface Temporal
        Specified by:
        with in class ChronoLocalDate
        Parameters:
        field - the field to set in the result, not null
        newValue - the new value of the field in the result
        Returns:
        an object of the same type with the specified field set, not null

      • plus

        public HijrahDate plus​(TemporalAmount amount)
        Description copied from interface: Temporal
        Returns an object of the same type as this object with an amount added.

        This adjusts this temporal, adding according to the rules of the specified amount. The amount is typically a Period but may be any other type implementing the TemporalAmount interface, such as Duration.

        Some example code indicating how and why this method is used: 

          date = date.plus(period);                  // add a Period instance
  date = date.plus(duration);                // add a Duration instance
  date = date.plus(workingDays(6));          // example user-written workingDays method

        Note that calling plus followed by minus is not guaranteed to return the same date-time.

        Specification for implementors

        Implementations must not alter either this object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
        Specified by:
        plus in interface Temporal
        Overrides:
        plus in class ChronoLocalDate
        Parameters:
        amount - the amount to add, not null
        Returns:
        an object of the same type with the specified adjustment made, not null

      • plus

        public HijrahDate plus​(long amountToAdd,
                       TemporalUnit unit)
        Description copied from interface: Temporal
        Returns an object of the same type as this object with the specified period added.

        This method returns a new object based on this one with the specified period added. For example, on a LocalDate, this could be used to add a number of years, months or days. The returned object will have the same observable type as this object.

        In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st January, then adding one month would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

        If the implementation represents a date-time that has boundaries, such as LocalTime, then the permitted units must include the boundary unit, but no multiples of the boundary unit. For example, LocalTime must accept DAYS but not WEEKS or MONTHS.

        Specification for implementors

        Implementations must check and handle all units defined in ChronoUnit. If the unit is supported, then the addition must be performed. If unsupported, then a DateTimeException must be thrown.

        If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.addTo(Temporal, long) passing this as the first argument.

        Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

        Specified by:
        plus in interface Temporal
        Parameters:
        amountToAdd - the amount of the specified unit to add, may be negative
        unit - the unit of the period to add, not null
        Returns:
        an object of the same type with the specified period added, not null

      • minus

        public HijrahDate minus​(TemporalAmount amount)
        Description copied from interface: Temporal
        Returns an object of the same type as this object with an amount subtracted.

        This adjusts this temporal, subtracting according to the rules of the specified amount. The amount is typically a Period but may be any other type implementing the TemporalAmount interface, such as Duration.

        Some example code indicating how and why this method is used: 

          date = date.minus(period);                  // subtract a Period instance
  date = date.minus(duration);                // subtract a Duration instance
  date = date.minus(workingDays(6));          // example user-written workingDays method

        Note that calling plus followed by minus is not guaranteed to return the same date-time.

        Specification for implementors

        Implementations must not alter either this object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
        Specified by:
        minus in interface Temporal
        Overrides:
        minus in class ChronoLocalDate
        Parameters:
        amount - the amount to subtract, not null
        Returns:
        an object of the same type with the specified adjustment made, not null

      • minus

        public HijrahDate minus​(long amountToAdd,
                        TemporalUnit unit)
        Description copied from interface: Temporal
        Returns an object of the same type as this object with the specified period subtracted.

        This method returns a new object based on this one with the specified period subtracted. For example, on a LocalDate, this could be used to subtract a number of years, months or days. The returned object will have the same observable type as this object.

        In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st March, then subtracting one month would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

        If the implementation represents a date-time that has boundaries, such as LocalTime, then the permitted units must include the boundary unit, but no multiples of the boundary unit. For example, LocalTime must accept DAYS but not WEEKS or MONTHS.

        Specification for implementors

        Implementations must behave in a manor equivalent to the default method behavior.

        Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

        Specified by:
        minus in interface Temporal
        Overrides:
        minus in class ChronoLocalDate
        Parameters:
        amountToAdd - the amount of the specified unit to subtract, may be negative
        unit - the unit of the period to subtract, not null
        Returns:
        an object of the same type with the specified period subtracted, not null

      • atTime

        public final ChronoLocalDateTime<HijrahDate> atTime​(LocalTime localTime)
        Description copied from class: ChronoLocalDate
        Combines this date with a time to create a ChronoLocalDateTime.

        This returns a ChronoLocalDateTime formed from this date at the specified time. All possible combinations of date and time are valid.

        Parameters:
        localTime - the local time to use, not null
        Returns:
        the local date-time formed from this date and the specified time, not null

      • toEpochDay

        public long toEpochDay()
        Description copied from class: ChronoLocalDate
        Converts this date to the Epoch Day.

        The Epoch Day count is a simple incrementing count of days where day 0 is 1970-01-01 (ISO). This definition is the same for all chronologies, enabling conversion.

        Overrides:
        toEpochDay in class ChronoLocalDate
        Returns:
        the Epoch Day equivalent to this date

      • isLeapYear

        public boolean isLeapYear()
        Checks if the year is a leap year, according to the Hijrah calendar system rules.
        Overrides:
        isLeapYear in class ChronoLocalDate
        Returns:
        true if this date is in a leap year

      • lengthOfMonth

        public int lengthOfMonth()
        Description copied from class: ChronoLocalDate
        Returns the length of the month represented by this date, as defined by the calendar system.

        This returns the length of the month in days.

        Specified by:
        lengthOfMonth in class ChronoLocalDate
        Returns:
        the length of the month in days

      • lengthOfYear

        public int lengthOfYear()
        Description copied from class: ChronoLocalDate
        Returns the length of the year represented by this date, as defined by the calendar system.

        This returns the length of the year in days.

        The default implementation uses ChronoLocalDate.isLeapYear() and returns 365 or 366.

        Overrides:
        lengthOfYear in class ChronoLocalDate
        Returns:
        the length of the year in days

      • until

        public long until​(Temporal endExclusive,
                  TemporalUnit unit)
        Description copied from interface: Temporal
        Calculates the period between this temporal and another temporal in terms of the specified unit.

        This calculates the period between two temporals in terms of a single unit. The start and end points are this and the specified temporal. The result will be negative if the end is before the start. For example, the period in hours between two temporal objects can be calculated using startTime.until(endTime, HOURS).

        The calculation returns a whole number, representing the number of complete units between the two temporals. For example, the period in hours between the times 11:30 and 13:29 will only be one hour as it is one minute short of two hours.

        There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use TemporalUnit.between(Temporal, Temporal): 

           // these two lines are equivalent
   between = thisUnit.between(start, end);
   between = start.until(end, thisUnit);
        The choice should be made based on which makes the code more readable.

        For example, this method allows the number of days between two dates to be calculated: 

           long daysBetween = DAYS.between(start, end);
   // or alternatively
   long daysBetween = start.until(end, DAYS);

        Specification for implementors

        Implementations must begin by checking to ensure that the input temporal object is of the same observable type as the implementation. They must then perform the calculation for all instances of ChronoUnit. A DateTimeException must be thrown for ChronoUnit instances that are unsupported.

        If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.between(Temporal, Temporal) passing this as the first argument and the input temporal as the second argument.

        In summary, implementations must behave in a manner equivalent to this code: 

          // check input temporal is the same type as this class
  if (unit instanceof ChronoUnit) {
    // if unit is supported, then calculate and return result
    // else throw DateTimeException for unsupported units
  }
  return unit.between(this, endTemporal);

        The target object must not be altered by this method.

        Specified by:
        until in interface Temporal
        Parameters:
        endExclusive - the end temporal, of the same type as this object, not null
        unit - the unit to measure the period in, not null
        Returns:
        the amount of the period between this and the end

      • until

        public ChronoPeriod until​(ChronoLocalDate endDate)
        Description copied from class: ChronoLocalDate
        Calculates the period between this date and another date as a ChronoPeriod.

        This calculates the period between two dates. All supplied chronologies calculate the period using years, months and days, however the ChronoPeriod API allows the period to be represented using other units.

        The start and end points are this and the specified date. The result will be negative if the end is before the start. The negative sign will be the same in each of year, month and day.

        The calculation is performed using the chronology of this date. If necessary, the input date will be converted to match.

        This instance is immutable and unaffected by this method call.

        Specified by:
        until in class ChronoLocalDate
        Parameters:
        endDate - the end date, exclusive, which may be in any chronology, not null
        Returns:
        the period between this date and the end date, not null