Class Month

All Implemented Interfaces:
Serializable, Comparable, MonthConstants, TimePeriod

public class Month extends RegularTimePeriod implements Serializable
Represents a single month. This class is immutable, which is a requirement for all RegularTimePeriod subclasses.
See Also:
  • Constructor Details

    • Month

      public Month()
      Constructs a new Month, based on the current system time. The time zone and locale are determined by the calendar returned by RegularTimePeriod.getCalendarInstance().
    • Month

      public Month(int month, int year)
      Constructs a new month instance. The time zone and locale are determined by the calendar returned by RegularTimePeriod.getCalendarInstance().
      Parameters:
      month - the month (in the range 1 to 12).
      year - the year.
    • Month

      public Month(int month, Year year)
      Constructs a new month instance. The time zone and locale are determined by the calendar returned by RegularTimePeriod.getCalendarInstance().
      Parameters:
      month - the month (in the range 1 to 12).
      year - the year.
    • Month

      public Month(Date time)
      Constructs a new Month instance, based on a date/time. The time zone and locale are determined by the calendar returned by RegularTimePeriod.getCalendarInstance().
      Parameters:
      time - the date/time (null not permitted).
      See Also:
    • Month

      public Month(Date time, TimeZone zone, Locale locale)
      Creates a new Month instance, based on the specified time, zone and locale.
      Parameters:
      time - the current time.
      zone - the time zone.
      locale - the locale.
    • Month

      public Month(Date time, Calendar calendar)
      Constructs a new instance, based on a particular date/time. The time zone and locale are determined by the calendar parameter.
      Parameters:
      time - the date/time (null not permitted).
      calendar - the calendar to use for calculations (null not permitted).
  • Method Details

    • getYear

      public Year getYear()
      Returns the year in which the month falls.
      Returns:
      The year in which the month falls (as a Year object).
    • getYearValue

      public int getYearValue()
      Returns the year in which the month falls.
      Returns:
      The year in which the month falls (as an int).
    • getMonth

      public int getMonth()
      Returns the month. Note that 1=JAN, 2=FEB, ...
      Returns:
      The month.
    • getFirstMillisecond

      public long getFirstMillisecond()
      Returns the first millisecond of the month. This will be determined relative to the time zone specified in the constructor, or in the calendar instance passed in the most recent call to the peg(Calendar) method.
      Specified by:
      getFirstMillisecond in class RegularTimePeriod
      Returns:
      The first millisecond of the month.
      See Also:
    • getLastMillisecond

      public long getLastMillisecond()
      Returns the last millisecond of the month. This will be determined relative to the time zone specified in the constructor, or in the calendar instance passed in the most recent call to the peg(Calendar) method.
      Specified by:
      getLastMillisecond in class RegularTimePeriod
      Returns:
      The last millisecond of the month.
      See Also:
    • peg

      public void peg(Calendar calendar)
      Recalculates the start date/time and end date/time for this time period relative to the supplied calendar (which incorporates a time zone).
      Specified by:
      peg in class RegularTimePeriod
      Parameters:
      calendar - the calendar (null not permitted).
    • previous

      Returns the month preceding this one. Note that the returned Month is "pegged" using the default calendar, obtained with RegularTimePeriod.getCalendarInstance(), irrespective of the time-zone used to peg of the current month (which is not recorded anywhere). See the peg(Calendar) method.
      Specified by:
      previous in class RegularTimePeriod
      Returns:
      The month preceding this one.
    • next

      Returns the month following this one. Note that the returned Month is "pegged" using the default calendar, obtained with RegularTimePeriod.getCalendarInstance(), irrespective of the time-zone used to peg of the current month (which is not recorded anywhere). See the peg(Calendar) method.
      Specified by:
      next in class RegularTimePeriod
      Returns:
      The month following this one.
    • getSerialIndex

      public long getSerialIndex()
      Returns a serial index number for the month.
      Specified by:
      getSerialIndex in class RegularTimePeriod
      Returns:
      The serial index number.
    • toString

      public String toString()
      Returns a string representing the month (e.g. "January 2002").

      To do: look at internationalisation.

      Overrides:
      toString in class RegularTimePeriod
      Returns:
      A string representing the month.
    • equals

      public boolean equals(Object obj)
      Tests the equality of this Month object to an arbitrary object. Returns true if the target is a Month instance representing the same month as this object. In all other cases, returns false.
      Overrides:
      equals in class Object
      Parameters:
      obj - the object (null permitted).
      Returns:
      true if month and year of this and object are the same.
    • hashCode

      public int hashCode()
      Returns a hash code for this object instance. The approach described by Joshua Bloch in "Effective Java" has been used here:

      http://developer.java.sun.com/developer/Books/effectivejava /Chapter3.pdf

      Overrides:
      hashCode in class Object
      Returns:
      A hash code.
    • compareTo

      public int compareTo(Object o1)
      Returns an integer indicating the order of this Month object relative to the specified object: negative == before, zero == same, positive == after.
      Specified by:
      compareTo in interface Comparable
      Parameters:
      o1 - the object to compare.
      Returns:
      negative == before, zero == same, positive == after.
    • getFirstMillisecond

      public long getFirstMillisecond(Calendar calendar)
      Returns the first millisecond of the month, evaluated using the supplied calendar (which determines the time zone).
      Specified by:
      getFirstMillisecond in class RegularTimePeriod
      Parameters:
      calendar - the calendar (null not permitted).
      Returns:
      The first millisecond of the month.
      Throws:
      NullPointerException - if calendar is null.
      See Also:
    • getLastMillisecond

      public long getLastMillisecond(Calendar calendar)
      Returns the last millisecond of the month, evaluated using the supplied calendar (which determines the time zone).
      Specified by:
      getLastMillisecond in class RegularTimePeriod
      Parameters:
      calendar - the calendar (null not permitted).
      Returns:
      The last millisecond of the month.
      Throws:
      NullPointerException - if calendar is null.
      See Also:
    • parseMonth

      public static Month parseMonth(String s)
      Parses the string argument as a month. This method is required to accept the format "YYYY-MM". It will also accept "MM-YYYY". Anything else, at the moment, is a bonus.
      Parameters:
      s - the string to parse (null permitted).
      Returns:
      null if the string is not parseable, the month otherwise.