Class SerialDate

java.lang.Object
org.jfree.chart.date.SerialDate
All Implemented Interfaces:
Serializable, Comparable, MonthConstants
Direct Known Subclasses:
SpreadsheetDate

public abstract class SerialDate
extends Object
implements Comparable, Serializable, MonthConstants
An abstract class that defines our requirements for manipulating dates, without tying down a particular implementation.

Requirement 1 : match at least what Excel does for dates; Requirement 2 : the date represented by the class is immutable;

Why not just use java.util.Date? We will, when it makes sense. At times, java.util.Date can be *too* precise - it represents an instant in time, accurate to 1/1000th of a second (with the date itself depending on the time-zone). Sometimes we just want to represent a particular day (e.g. 21 January 2015) without concerning ourselves about the time of day, or the time-zone, or anything else. That's what we've defined SerialDate for.

You can call getInstance() to get a concrete subclass of SerialDate, without worrying about the exact implementation.

See Also:
Serialized Form
  • Field Details

  • Constructor Details

    • SerialDate

      protected SerialDate()
      Default constructor.
  • Method Details

    • isValidWeekdayCode

      public static boolean isValidWeekdayCode​(int code)
      Returns true if the supplied integer code represents a valid day-of-the-week, and false otherwise.
      Parameters:
      code - the code being checked for validity.
      Returns:
      true if the supplied integer code represents a valid day-of-the-week, and false otherwise.
    • stringToWeekdayCode

      public static int stringToWeekdayCode​(String s)
      Converts the supplied string to a day of the week.
      Parameters:
      s - a string representing the day of the week.
      Returns:
      -1 if the string is not convertable, the day of the week otherwise.
    • weekdayCodeToString

      public static String weekdayCodeToString​(int weekday)
      Returns a string representing the supplied day-of-the-week.

      Need to find a better approach.

      Parameters:
      weekday - the day of the week.
      Returns:
      a string representing the supplied day-of-the-week.
    • getMonths

      public static String[] getMonths()
      Returns an array of month names.
      Returns:
      an array of month names.
    • getMonths

      public static String[] getMonths​(boolean shortened)
      Returns an array of month names.
      Parameters:
      shortened - a flag indicating that shortened month names should be returned.
      Returns:
      an array of month names.
    • isValidMonthCode

      public static boolean isValidMonthCode​(int code)
      Returns true if the supplied integer code represents a valid month.
      Parameters:
      code - the code being checked for validity.
      Returns:
      true if the supplied integer code represents a valid month.
    • monthCodeToQuarter

      public static int monthCodeToQuarter​(int code)
      Returns the quarter for the specified month.
      Parameters:
      code - the month code (1-12).
      Returns:
      the quarter that the month belongs to.
    • monthCodeToString

      public static String monthCodeToString​(int month)
      Returns a string representing the supplied month.

      The string returned is the long form of the month name taken from the default locale.

      Parameters:
      month - the month.
      Returns:
      a string representing the supplied month.
    • monthCodeToString

      public static String monthCodeToString​(int month, boolean shortened)
      Returns a string representing the supplied month.

      The string returned is the long or short form of the month name taken from the default locale.

      Parameters:
      month - the month.
      shortened - if true return the abbreviation of the month.
      Returns:
      a string representing the supplied month.
    • stringToMonthCode

      public static int stringToMonthCode​(String s)
      Converts a string to a month code.

      This method will return one of the constants JANUARY, FEBRUARY, ..., DECEMBER that corresponds to the string. If the string is not recognised, this method returns -1.

      Parameters:
      s - the string to parse.
      Returns:
      -1 if the string is not parseable, the month of the year otherwise.
    • isValidWeekInMonthCode

      public static boolean isValidWeekInMonthCode​(int code)
      Returns true if the supplied integer code represents a valid week-in-the-month, and false otherwise.
      Parameters:
      code - the code being checked for validity.
      Returns:
      true if the supplied integer code represents a valid week-in-the-month.
    • isLeapYear

      public static boolean isLeapYear​(int yyyy)
      Determines whether or not the specified year is a leap year.
      Parameters:
      yyyy - the year (in the range 1900 to 9999).
      Returns:
      true if the specified year is a leap year.
    • leapYearCount

      public static int leapYearCount​(int yyyy)
      Returns the number of leap years from 1900 to the specified year INCLUSIVE.

      Note that 1900 is not a leap year.

      Parameters:
      yyyy - the year (in the range 1900 to 9999).
      Returns:
      the number of leap years from 1900 to the specified year.
    • lastDayOfMonth

      public static int lastDayOfMonth​(int month, int yyyy)
      Returns the number of the last day of the month, taking into account leap years.
      Parameters:
      month - the month.
      yyyy - the year (in the range 1900 to 9999).
      Returns:
      the number of the last day of the month.
    • addDays

      public static SerialDate addDays​(int days, SerialDate base)
      Creates a new date by adding the specified number of days to the base date.
      Parameters:
      days - the number of days to add (can be negative).
      base - the base date.
      Returns:
      a new date.
    • addMonths

      public static SerialDate addMonths​(int months, SerialDate base)
      Creates a new date by adding the specified number of months to the base date.

      If the base date is close to the end of the month, the day on the result may be adjusted slightly: 31 May + 1 month = 30 June.

      Parameters:
      months - the number of months to add (can be negative).
      base - the base date.
      Returns:
      a new date.
    • addYears

      public static SerialDate addYears​(int years, SerialDate base)
      Creates a new date by adding the specified number of years to the base date.
      Parameters:
      years - the number of years to add (can be negative).
      base - the base date.
      Returns:
      A new date.
    • getPreviousDayOfWeek

      public static SerialDate getPreviousDayOfWeek​(int targetWeekday, SerialDate base)
      Returns the latest date that falls on the specified day-of-the-week and is BEFORE the base date.
      Parameters:
      targetWeekday - a code for the target day-of-the-week.
      base - the base date.
      Returns:
      the latest date that falls on the specified day-of-the-week and is BEFORE the base date.
    • getFollowingDayOfWeek

      public static SerialDate getFollowingDayOfWeek​(int targetWeekday, SerialDate base)
      Returns the earliest date that falls on the specified day-of-the-week and is AFTER the base date.
      Parameters:
      targetWeekday - a code for the target day-of-the-week.
      base - the base date.
      Returns:
      the earliest date that falls on the specified day-of-the-week and is AFTER the base date.
    • getNearestDayOfWeek

      public static SerialDate getNearestDayOfWeek​(int targetDOW, SerialDate base)
      Returns the date that falls on the specified day-of-the-week and is CLOSEST to the base date.
      Parameters:
      targetDOW - a code for the target day-of-the-week.
      base - the base date.
      Returns:
      the date that falls on the specified day-of-the-week and is CLOSEST to the base date.
    • getEndOfCurrentMonth

      Rolls the date forward to the last day of the month.
      Parameters:
      base - the base date.
      Returns:
      a new serial date.
    • weekInMonthToString

      public static String weekInMonthToString​(int count)
      Returns a string corresponding to the week-in-the-month code.

      Need to find a better approach.

      Parameters:
      count - an integer code representing the week-in-the-month.
      Returns:
      a string corresponding to the week-in-the-month code.
    • relativeToString

      public static String relativeToString​(int relative)
      Returns a string representing the supplied 'relative'.

      Need to find a better approach.

      Parameters:
      relative - a constant representing the 'relative'.
      Returns:
      a string representing the supplied 'relative'.
    • createInstance

      public static SerialDate createInstance​(int day, int month, int yyyy)
      Factory method that returns an instance of some concrete subclass of SerialDate.
      Parameters:
      day - the day (1-31).
      month - the month (1-12).
      yyyy - the year (in the range 1900 to 9999).
      Returns:
      An instance of SerialDate.
    • createInstance

      public static SerialDate createInstance​(int serial)
      Factory method that returns an instance of some concrete subclass of SerialDate.
      Parameters:
      serial - the serial number for the day (1 January 1900 = 2).
      Returns:
      a instance of SerialDate.
    • createInstance

      public static SerialDate createInstance​(Date date)
      Factory method that returns an instance of a subclass of SerialDate.
      Parameters:
      date - A Java date object.
      Returns:
      a instance of SerialDate.
    • toSerial

      public abstract int toSerial()
      Returns the serial number for the date, where 1 January 1900 = 2 (this corresponds, almost, to the numbering system used in Microsoft Excel for Windows and Lotus 1-2-3).
      Returns:
      the serial number for the date.
    • toDate

      public abstract Date toDate()
      Returns a java.util.Date. Since java.util.Date has more precision than SerialDate, we need to define a convention for the 'time of day'.
      Returns:
      this as java.util.Date.
    • getDescription

      Returns the description that is attached to the date. It is not required that a date have a description, but for some applications it is useful.
      Returns:
      The description (possibly null).
    • setDescription

      public void setDescription​(String description)
      Sets the description for the date.
      Parameters:
      description - the description for this date (null permitted).
    • toString

      public String toString()
      Converts the date to a string.
      Overrides:
      toString in class Object
      Returns:
      a string representation of the date.
    • getYYYY

      public abstract int getYYYY()
      Returns the year (assume a valid range of 1900 to 9999).
      Returns:
      the year.
    • getMonth

      public abstract int getMonth()
      Returns the month (January = 1, February = 2, March = 3).
      Returns:
      the month of the year.
    • getDayOfMonth

      public abstract int getDayOfMonth()
      Returns the day of the month.
      Returns:
      the day of the month.
    • getDayOfWeek

      public abstract int getDayOfWeek()
      Returns the day of the week.
      Returns:
      the day of the week.
    • compare

      public abstract int compare​(SerialDate other)
      Returns the difference (in days) between this date and the specified 'other' date.

      The result is positive if this date is after the 'other' date and negative if it is before the 'other' date.

      Parameters:
      other - the date being compared to.
      Returns:
      the difference between this and the other date.
    • isOn

      public abstract boolean isOn​(SerialDate other)
      Returns true if this SerialDate represents the same date as the specified SerialDate.
      Parameters:
      other - the date being compared to.
      Returns:
      true if this SerialDate represents the same date as the specified SerialDate.
    • isBefore

      public abstract boolean isBefore​(SerialDate other)
      Returns true if this SerialDate represents an earlier date compared to the specified SerialDate.
      Parameters:
      other - The date being compared to.
      Returns:
      true if this SerialDate represents an earlier date compared to the specified SerialDate.
    • isOnOrBefore

      public abstract boolean isOnOrBefore​(SerialDate other)
      Returns true if this SerialDate represents the same date as the specified SerialDate.
      Parameters:
      other - the date being compared to.
      Returns:
      true if this SerialDate represents the same date as the specified SerialDate.
    • isAfter

      public abstract boolean isAfter​(SerialDate other)
      Returns true if this SerialDate represents the same date as the specified SerialDate.
      Parameters:
      other - the date being compared to.
      Returns:
      true if this SerialDate represents the same date as the specified SerialDate.
    • isOnOrAfter

      public abstract boolean isOnOrAfter​(SerialDate other)
      Returns true if this SerialDate represents the same date as the specified SerialDate.
      Parameters:
      other - the date being compared to.
      Returns:
      true if this SerialDate represents the same date as the specified SerialDate.
    • isInRange

      public abstract boolean isInRange​(SerialDate d1, SerialDate d2)
      Returns true if this SerialDate is within the specified range (INCLUSIVE). The date order of d1 and d2 is not important.
      Parameters:
      d1 - a boundary date for the range.
      d2 - the other boundary date for the range.
      Returns:
      A boolean.
    • isInRange

      public abstract boolean isInRange​(SerialDate d1, SerialDate d2, int include)
      Returns true if this SerialDate is within the specified range (caller specifies whether or not the end-points are included). The date order of d1 and d2 is not important.
      Parameters:
      d1 - a boundary date for the range.
      d2 - the other boundary date for the range.
      include - a code that controls whether or not the start and end dates are included in the range.
      Returns:
      A boolean.
    • getPreviousDayOfWeek

      public SerialDate getPreviousDayOfWeek​(int targetDOW)
      Returns the latest date that falls on the specified day-of-the-week and is BEFORE this date.
      Parameters:
      targetDOW - a code for the target day-of-the-week.
      Returns:
      the latest date that falls on the specified day-of-the-week and is BEFORE this date.
    • getFollowingDayOfWeek

      public SerialDate getFollowingDayOfWeek​(int targetDOW)
      Returns the earliest date that falls on the specified day-of-the-week and is AFTER this date.
      Parameters:
      targetDOW - a code for the target day-of-the-week.
      Returns:
      the earliest date that falls on the specified day-of-the-week and is AFTER this date.
    • getNearestDayOfWeek

      public SerialDate getNearestDayOfWeek​(int targetDOW)
      Returns the nearest date that falls on the specified day-of-the-week.
      Parameters:
      targetDOW - a code for the target day-of-the-week.
      Returns:
      the nearest date that falls on the specified day-of-the-week.