Enum DayOfWeek

  • All Implemented Interfaces:
    Serializable, Comparable<DayOfWeek>, Calendrical

    public enum DayOfWeek
    extends Enum<DayOfWeek>
    implements Calendrical
    A day-of-week, such as 'Tuesday'.

    DayOfWeek is an enum representing the 7 days of the week - Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.

    The calendrical framework requires date-time fields to have an int value. The int value follows the ISO-8601 standard, from 1 (Monday) to 7 (Sunday). It is recommended that applications use the enum rather than the int value to ensure code clarity.

    Do not use ordinal() to obtain the numeric representation of DayOfWeek. Use getValue() instead.

    This enum represents a common concept that is found in many calendar systems. As such, this enum may be used by any calendar system that has the day-of-week concept with a seven day week where the names are equivalent to those defined. Note that the implementation of DateTimeFieldRule for day-of-week may vary by calendar system.

    DayOfWeek is an immutable and thread-safe enum.

    Author:
    Michael Nascimento Santos, Stephen Colebourne
    • Enum Constant Detail

      • MONDAY

        public static final DayOfWeek MONDAY
        The singleton instance for the day-of-week of Monday. This has the numeric value of 1.
      • TUESDAY

        public static final DayOfWeek TUESDAY
        The singleton instance for the day-of-week of Tuesday. This has the numeric value of 2.
      • WEDNESDAY

        public static final DayOfWeek WEDNESDAY
        The singleton instance for the day-of-week of Wednesday. This has the numeric value of 3.
      • THURSDAY

        public static final DayOfWeek THURSDAY
        The singleton instance for the day-of-week of Thursday. This has the numeric value of 4.
      • FRIDAY

        public static final DayOfWeek FRIDAY
        The singleton instance for the day-of-week of Friday. This has the numeric value of 5.
      • SATURDAY

        public static final DayOfWeek SATURDAY
        The singleton instance for the day-of-week of Saturday. This has the numeric value of 6.
      • SUNDAY

        public static final DayOfWeek SUNDAY
        The singleton instance for the day-of-week of Sunday. This has the numeric value of 7.
    • Method Detail

      • values

        public static DayOfWeek[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
        for (DayOfWeek c : DayOfWeek.values())
            System.out.println(c);
        
        Returns:
        an array containing the constants of this enum type, in the order they are declared
      • valueOf

        public static DayOfWeek valueOf​(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        IllegalArgumentException - if this enum type has no constant with the specified name
        NullPointerException - if the argument is null
      • of

        public static DayOfWeek of​(int dayOfWeek)
        Obtains an instance of DayOfWeek from an int value.

        DayOfWeek is an enum representing the 7 days of the week. This factory allows the enum to be obtained from the int value. The int value follows the ISO-8601 standard, from 1 (Monday) to 7 (Sunday).

        An exception is thrown if the value is invalid. The exception uses the ISOChronology day-of-week rule to indicate the failed rule.

        Parameters:
        dayOfWeek - the day-of-week to represent, from 1 (Monday) to 7 (Sunday)
        Returns:
        the DayOfWeek singleton, never null
        Throws:
        IllegalCalendarFieldValueException - if the day-of-week is invalid
      • firstDayOfWeekFor

        public static DayOfWeek firstDayOfWeekFor​(Locale locale)
        Returns the DayOfWeek instance that corresponds to the first day-of-week for a given locale.

        If there is no information for a locale, MONDAY is returned.

        Parameters:
        locale - the locale to use, not null
        Returns:
        the DayOfWeek singleton, never null
      • getValue

        public int getValue()
        Gets the day-of-week int value.

        The values are numbered following the ISO-8601 standard, from 1 (Monday) to 7 (Sunday).

        Returns:
        the day-of-week, from 1 (Monday) to 7 (Sunday)
      • get

        public <T> T get​(CalendricalRule<T> rule)
        Gets the value of the specified calendrical rule.

        This returns the one of the day-of-week values if the type of the rule is DayOfWeek. Other rules will return null.

        Specified by:
        get in interface Calendrical
        Parameters:
        rule - the rule to use, not null
        Returns:
        the value for the rule, null if the value cannot be returned
      • getShortText

        public String getShortText​(Locale locale)
        Gets the short textual representation of this day-of-week, such as 'Mon' or 'Fri'.

        This method is notionally specific to ISOChronology as it uses the day-of-week rule to obtain the text. However, it is expected that the text will be equivalent for all day-of-week rules, thus this aspect of the implementation should be irrelevant to applications.

        If there is no textual mapping for the locale, then the ISO-8601 value is returned as per Integer.toString().

        Parameters:
        locale - the locale to use, not null
        Returns:
        the short text value of the day-of-week, never null
      • getText

        public String getText​(Locale locale)
        Gets the full textual representation of this day-of-week, such as 'Monday' or 'Friday'.

        This method is notionally specific to ISOChronology as it uses the day-of-week rule to obtain the text. However, it is expected that the text will be equivalent for all day-of-week rules, thus this aspect of the implementation should be irrelevant to applications.

        If there is no textual mapping for the locale, then the ISO-8601 value is returned as per Integer.toString().

        Parameters:
        locale - the locale to use, not null
        Returns:
        the full text value of the day-of-week, never null
      • isMonday

        public boolean isMonday()
        Is this instance representing Monday.
        Returns:
        true if this instance represents Monday
      • isTuesday

        public boolean isTuesday()
        Is this instance representing Tuesday.
        Returns:
        true if this instance represents Tuesday
      • isWednesday

        public boolean isWednesday()
        Is this instance representing Wednesday.
        Returns:
        true if this instance represents Wednesday
      • isThursday

        public boolean isThursday()
        Is this instance representing Thursday.
        Returns:
        true if this instance represents Thursday
      • isFriday

        public boolean isFriday()
        Is this instance representing Friday.
        Returns:
        true if this instance represents Friday
      • isSaturday

        public boolean isSaturday()
        Is this instance representing Saturday.
        Returns:
        true if this instance represents Saturday
      • isSunday

        public boolean isSunday()
        Is this instance representing Sunday.
        Returns:
        true if this instance represents Sunday
      • next

        public DayOfWeek next()
        Gets the next day-of-week.

        This calculates based on the time-line, thus it rolls around the end of the week. The next day after Sunday is Monday.

        Returns:
        the next day-of-week, never null
      • previous

        public DayOfWeek previous()
        Gets the previous day-of-week.

        This calculates based on the time-line, thus it rolls around the end of the week. The previous day before Monday is Sunday.

        Returns:
        the previous day-of-week, never null
      • roll

        public DayOfWeek roll​(int days)
        Rolls the day-of-week, adding the specified number of days.

        This calculates based on the time-line, thus it rolls around the end of the week from Sunday to Monday. The days to roll by may be negative.

        This instance is immutable and unaffected by this method call.

        Parameters:
        days - the days to roll by, positive or negative
        Returns:
        the resulting day-of-week, never null