Package com.ibm.icu.util

Class ChineseCalendar

  • All Implemented Interfaces:
    Serializable, Cloneable, Comparable<Calendar>
    Direct Known Subclasses:
    DangiCalendar
    public class ChineseCalendar
extends Calendar
    ChineseCalendar is a concrete subclass of Calendar that implements a traditional Chinese calendar. The traditional Chinese calendar is a lunisolar calendar: Each month starts on a new moon, and the months are numbered according to solar events, specifically, to guarantee that month 11 always contains the winter solstice. In order to accomplish this, leap months are inserted in certain years. Leap months are numbered the same as the month they follow. The decision of which month is a leap month depends on the relative movements of the sun and moon.

    All astronomical computations are performed with respect to a time zone of GMT+8:00 and a longitude of 120 degrees east. Although some calendars implement a historically more accurate convention of using Beijing's local longitude (116 degrees 25 minutes east) and time zone (GMT+7:45:40) for dates before 1929, we do not implement this here.

    Years are counted in two different ways in the Chinese calendar. The first method is by sequential numbering from the 61st year of the reign of Huang Di, 2637 BCE, which is designated year 1 on the Chinese calendar. The second method uses 60-year cycles from the same starting point, which is designated year 1 of cycle 1. In this class, the EXTENDED_YEAR field contains the sequential year count. The ERA field contains the cycle number, and the YEAR field contains the year of the cycle, a value between 1 and 60.

    There is some variation in what is considered the starting point of the calendar, with some sources starting in the first year of the reign of Huang Di, rather than the 61st. This gives continuous year numbers 60 years greater and cycle numbers one greater than what this class implements.

    Because ChineseCalendar defines an additional field and redefines the way the ERA field is used, it requires a new format class, ChineseDateFormat. As always, use the methods DateFormat.getXxxInstance(Calendar cal,...) to obtain a formatter for this calendar.

    References:

    This class should not be subclassed.

    ChineseCalendar usually should be instantiated using Calendar.getInstance(ULocale) passing in a ULocale with the tag "@calendar=chinese".

    See Also:
    Calendar, Serialized Form

    • Constructor Detail

      • ChineseCalendar

        public ChineseCalendar()
        Construct a ChineseCalendar with the default time zone and locale.

      • ChineseCalendar

        public ChineseCalendar​(Date date)
        Construct a ChineseCalendar with the give date set in the default time zone with the default locale.
        Parameters:
        date - The date to which the new calendar is set.

      • ChineseCalendar

        public ChineseCalendar​(int year,
                       int month,
                       int isLeapMonth,
                       int date)
        Constructs a ChineseCalendar with the given date set in the default time zone with the default FORMAT locale.
        Parameters:
        year - The value used to set the calendar's YEAR time field.
        month - The value used to set the calendar's MONTH time field. The value is 0-based. e.g., 0 for January.
        isLeapMonth - The value used to set the Chinese calendar's (@link #IS_LEAP_MONTH) time field.
        date - The value used to set the calendar's DATE time field.
        See Also:
        ULocale.Category.FORMAT

      • ChineseCalendar

        public ChineseCalendar​(int year,
                       int month,
                       int isLeapMonth,
                       int date,
                       int hour,
                       int minute,
                       int second)
        Constructs a ChineseCalendar with the given date and time set for the default time zone with the default FORMAT locale.
        Parameters:
        year - the value used to set the YEAR time field in the calendar.
        month - the value used to set the MONTH time field in the calendar. Note that the month value is 0-based. e.g., 0 for January.
        isLeapMonth - the value used to set the Calendar.IS_LEAP_MONTH time field in the calendar.
        date - the value used to set the DATE time field in the calendar.
        hour - the value used to set the HOUR_OF_DAY time field in the calendar.
        minute - the value used to set the MINUTE time field in the calendar.
        second - the value used to set the SECOND time field in the calendar.
        See Also:
        ULocale.Category.FORMAT

      • ChineseCalendar

        public ChineseCalendar​(int era,
                       int year,
                       int month,
                       int isLeapMonth,
                       int date)
        Constructs a ChineseCalendar with the given date set in the default time zone with the default FORMAT locale.
        Parameters:
        era - The value used to set the calendar's ERA time field.
        year - The value used to set the calendar's YEAR time field.
        month - The value used to set the calendar's MONTH time field. The value is 0-based. e.g., 0 for January.
        isLeapMonth - The value used to set the Chinese calendar's (@link #IS_LEAP_MONTH) time field.
        date - The value used to set the calendar's DATE time field.
        See Also:
        ULocale.Category.FORMAT

      • ChineseCalendar

        public ChineseCalendar​(int era,
                       int year,
                       int month,
                       int isLeapMonth,
                       int date,
                       int hour,
                       int minute,
                       int second)
        Constructs a ChineseCalendar with the given date and time set for the default time zone with the default FORMAT locale.
        Parameters:
        era - the value used to set the calendar's ERA time field.
        year - the value used to set the YEAR time field in the calendar.
        month - the value used to set the MONTH time field in the calendar. Note that the month value is 0-based. e.g., 0 for January.
        isLeapMonth - the value used to set the Calendar.IS_LEAP_MONTH time field in the calendar.
        date - the value used to set the DATE time field in the calendar.
        hour - the value used to set the HOUR_OF_DAY time field in the calendar.
        minute - the value used to set the MINUTE time field in the calendar.
        second - the value used to set the SECOND time field in the calendar.
        See Also:
        ULocale.Category.FORMAT

      • ChineseCalendar

        public ChineseCalendar​(Locale aLocale)
        Constructs a ChineseCalendar based on the current time in the default time zone with the given locale.
        Parameters:
        aLocale - The given locale

      • ChineseCalendar

        public ChineseCalendar​(TimeZone zone)
        Construct a ChineseCalendar based on the current time in the given time zone with the default FORMAT locale.
        Parameters:
        zone - the given time zone
        See Also:
        ULocale.Category.FORMAT

      • ChineseCalendar

        public ChineseCalendar​(TimeZone zone,
                       Locale aLocale)
        Construct a ChineseCalendar based on the current time in the given time zone with the given locale.
        Parameters:
        zone - the given time zone
        aLocale - the given locale

      • ChineseCalendar

        public ChineseCalendar​(ULocale locale)
        Constructs a ChineseCalendar based on the current time in the default time zone with the given locale.
        Parameters:
        locale - the given ulocale

      • ChineseCalendar

        public ChineseCalendar​(TimeZone zone,
                       ULocale locale)
        Construct a ChineseCalendar based on the current time with the given time zone with the given locale.
        Parameters:
        zone - the given time zone
        locale - the given ulocale

      • ChineseCalendar

        @Deprecated
protected ChineseCalendar​(TimeZone zone,
                          ULocale locale,
                          int epochYear,
                          TimeZone zoneAstroCalc)
        Deprecated.
        This API is ICU internal only.
        Construct a ChineseCalenar based on the current time with the given time zone, the locale, the epoch year and the time zone used for astronomical calculation.

    • Method Detail

      • handleGetLimit

        protected int handleGetLimit​(int field,
                             int limitType)
        Override Calendar to return the limit value for the given field.
        Specified by:
        handleGetLimit in class Calendar
        Parameters:
        field - one of the above field numbers
        limitType - one of MINIMUM, GREATEST_MINIMUM, LEAST_MAXIMUM, or MAXIMUM

      • handleGetExtendedYear

        protected int handleGetExtendedYear()
        Implement abstract Calendar method to return the extended year defined by the current fields. This will use either the ERA and YEAR field as the cycle and year-of-cycle, or the EXTENDED_YEAR field as the continuous year count, depending on which is newer.
        Specified by:
        handleGetExtendedYear in class Calendar
        Returns:
        the extended year

      • handleGetMonthLength

        protected int handleGetMonthLength​(int extendedYear,
                                   int month)
        Override Calendar method to return the number of days in the given extended year and month.

        Note: This method also reads the IS_LEAP_MONTH field to determine whether or not the given month is a leap month.

        Overrides:
        handleGetMonthLength in class Calendar

      • handleGetDateFormat

        protected DateFormat handleGetDateFormat​(String pattern,
                                         String override,
                                         ULocale locale)
        Creates a DateFormat appropriate to this calendar. This is a framework method for subclasses to override. This method is responsible for creating the calendar-specific DateFormat and DateFormatSymbols objects as needed.
        Overrides:
        handleGetDateFormat in class Calendar
        Parameters:
        pattern - the pattern, specific to the DateFormat subclass
        locale - the locale for which the symbols should be drawn
        Returns:
        a DateFormat appropriate to this calendar

      • add

        public void add​(int field,
                int amount)
        Override Calendar to handle leap months properly.
        Overrides:
        add in class Calendar
        Parameters:
        field - the time field.
        amount - the amount to add to the field.
        See Also:
        Calendar.roll(int, int)

      • roll

        public void roll​(int field,
                 int amount)
        Override Calendar to handle leap months properly.
        Overrides:
        roll in class Calendar
        Parameters:
        field - the calendar field to roll.
        amount - the amount by which the field should be rolled.
        See Also:
        Calendar.roll(int, boolean), Calendar.add(int, int)

      • handleComputeFields

        protected void handleComputeFields​(int julianDay)
        Override Calendar to compute several fields specific to the Chinese calendar system. These are:
        • ERA
        • YEAR
        • MONTH
        • DAY_OF_MONTH
        • DAY_OF_YEAR
        • EXTENDED_YEAR
        The DAY_OF_WEEK and DOW_LOCAL fields are already set when this method is called. The getGregorianXxx() methods return Gregorian calendar equivalents for the given Julian day.

        Compute the ChineseCalendar-specific field IS_LEAP_MONTH.

        Overrides:
        handleComputeFields in class Calendar

      • handleComputeMonthStart

        protected int handleComputeMonthStart​(int eyear,
                                      int month,
                                      boolean useMonth)
        Return the Julian day number of day before the first day of the given month in the given extended year.

        Note: This method reads the IS_LEAP_MONTH field to determine whether the given month is a leap month.

        Specified by:
        handleComputeMonthStart in class Calendar
        Parameters:
        eyear - the extended year
        month - the zero-based month. The month is also determined by reading the IS_LEAP_MONTH field.
        useMonth - if false, compute the day before the first day of the given year, otherwise, compute the day before the first day of the given month
        Returns:
        the Julian day number of the day before the first day of the given month and year

      • getType

        public String getType()
        Returns the calendar type name string for this Calendar object. The returned string is the legacy ICU calendar attribute value, for example, "gregorian" or "japanese".

        See type="old type name" for the calendar attribute of locale IDs at http://www.unicode.org/reports/tr35/#Key_Type_Definitions

        Overrides:
        getType in class Calendar
        Returns:
        legacy calendar type name string

      • haveDefaultCentury

        @Deprecated
public boolean haveDefaultCentury()
        Deprecated.
        This API is ICU internal only.
        Returns if two digit representation of year in this calendar type customarily implies a default century (i.e. 03 -> 2003). The default implementation returns true. A subclass may return false if such practice is not applicable (for example, Chinese calendar and Japanese calendar).
        Overrides:
        haveDefaultCentury in class Calendar
        Returns:
        true if this calendar has a default century.