java.util
Class GregorianCalendar

java.lang.Object
  java.util.Calendar
      java.util.GregorianCalendar

All Implemented Interfaces:

Serializable, Cloneable, Comparable<Calendar>

public class GregorianCalendar
extends Calendar

GregorianCalendar provides the conversion between Dates and integer calendar fields, such as the month, year or minute, for the Gregorian calendar. See Calendar for the defined fields.

See Also:

Calendar, TimeZone, SimpleTimeZone, Serialized Form

Field Summary

static int	AD Value for the AD era.
static int	BC Value for the BC era.
(package private) static byte[]	DaysInMonth

Fields inherited from class java.util.Calendar

AM, AM_PM, APRIL, areFieldsSet, AUGUST, DATE, DAY_OF_MONTH, DAY_OF_WEEK, DAY_OF_WEEK_IN_MONTH, DAY_OF_YEAR, DECEMBER, DST_OFFSET, ERA, FEBRUARY, FIELD_COUNT, fields, FRIDAY, HOUR, HOUR_OF_DAY, isSet, isTimeSet, JANUARY, JULY, JUNE, lastDateFieldSet, lastTimeFieldSet, MARCH, MAY, MILLISECOND, MINUTE, MONDAY, MONTH, NOVEMBER, OCTOBER, PM, SATURDAY, SECOND, SEPTEMBER, SUNDAY, THURSDAY, time, TUESDAY, UNDECIMBER, WEDNESDAY, WEEK_OF_MONTH, WEEK_OF_YEAR, YEAR, ZONE_OFFSET

Constructor Summary

GregorianCalendar()
Constructs a new GregorianCalendar initialized to the current date and time.

GregorianCalendar(boolean ignored)

GregorianCalendar(int year, int month, int day)
Constructs a new GregorianCalendar initialized to midnight in the default time zone on the specified date.

GregorianCalendar(int year, int month, int day, int hour, int minute)
Constructs a new GregorianCalendar initialized to the specified date and time.

GregorianCalendar(int year, int month, int day, int hour, int minute, int second)
Constructs a new GregorianCalendar initialized to the specified date and time.

GregorianCalendar(Locale locale)
Constructs a new GregorianCalendar initialized to the current date and time and using the specified Locale.

GregorianCalendar(long milliseconds)

GregorianCalendar(TimeZone timezone)
Constructs a new GregorianCalendar initialized to the current date and time and using the specified TimeZone.

GregorianCalendar(TimeZone timezone, Locale locale)
Constructs a new GregorianCalendar initialized to the current date and time and using the specified TimeZone and Locale.

Method Summary

void	add(int field, int value) Adds the specified amount to a Calendar field.
Object	clone() Creates new instance of GregorianCalendar with the same properties.
protected void	computeFields() Computes the Calendar fields from the time.
protected void	computeTime() Computes the time from the Calendar fields.
boolean	equals(Object object) Compares the specified object to this GregorianCalendar and answer if they are equal.
int	getActualMaximum(int field) Gets the maximum value of the specified field for the current date.
int	getActualMinimum(int field) Gets the minimum value of the specified field for the current date.
int	getGreatestMinimum(int field) Gets the greatest minimum value of the specified field.
Date	getGregorianChange() Returns the gregorian change date of this calendar.
int	getLeastMaximum(int field) Gets the smallest maximum value of the specified field.
int	getMaximum(int field) Gets the greatest maximum value of the specified field.
int	getMinimum(int field) Gets the smallest minimum value of the specified field.
(package private) int	getOffset(long localTime)
int	hashCode() Returns an integer hash code for the receiver.
boolean	isLeapYear(int year) Returns if the specified year is a leap year.
void	roll(int field, boolean increment) Increment or decrement the specified field and wrap the value of the field when it goes beyond the maximum or minimum value for the current date.
void	roll(int field, int value) Adds the specified amount the specified field and wrap the value of the field when it goes beyond the maximum or minimum value for the current date.
void	setFirstDayOfWeek(int value) Sets the first day of the week for this Calendar.
void	setGregorianChange(Date date) Sets the gregorian change date of this calendar.
void	setMinimalDaysInFirstWeek(int value) Sets the minimal days in the first week of the year.

Methods inherited from class java.util.Calendar

after, before, clear, clear, compareTo, complete, get, getAvailableLocales, getFirstDayOfWeek, getInstance, getInstance, getInstance, getInstance, getMinimalDaysInFirstWeek, getTime, getTimeInMillis, getTimeZone, internalGet, isLenient, isSet, set, set, set, set, setLenient, setTime, setTimeInMillis, setTimeZone, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

BC

public static final int BC

Value for the BC era.

See Also:

Constant Field Values

AD

public static final int AD

Value for the AD era.

See Also:

Constant Field Values

DaysInMonth

static byte[] DaysInMonth

Constructor Detail

GregorianCalendar

public GregorianCalendar()

Constructs a new GregorianCalendar initialized to the current date and time.

GregorianCalendar

public GregorianCalendar(int year,
                         int month,
                         int day)

Constructs a new GregorianCalendar initialized to midnight in the default time zone on the specified date.

Parameters:

year - the year

month - the month

day - the day of the month

GregorianCalendar

public GregorianCalendar(int year,
                         int month,
                         int day,
                         int hour,
                         int minute)

Constructs a new GregorianCalendar initialized to the specified date and time.

Parameters:

year - the year

month - the month

day - the day of the month

hour - the hour

minute - the minute

GregorianCalendar

public GregorianCalendar(int year,
                         int month,
                         int day,
                         int hour,
                         int minute,
                         int second)

Constructs a new GregorianCalendar initialized to the specified date and time.

Parameters:

year - the year

month - the month

day - the day of the month

hour - the hour

minute - the minute

second - the second

GregorianCalendar

GregorianCalendar(long milliseconds)

GregorianCalendar

public GregorianCalendar(Locale locale)

Constructs a new GregorianCalendar initialized to the current date and time and using the specified Locale.

Parameters:

locale - the Locale

GregorianCalendar

public GregorianCalendar(TimeZone timezone)

Constructs a new GregorianCalendar initialized to the current date and time and using the specified TimeZone.

Parameters:

timezone - the TimeZone

GregorianCalendar

public GregorianCalendar(TimeZone timezone,
                         Locale locale)

Constructs a new GregorianCalendar initialized to the current date and time and using the specified TimeZone and Locale.

Parameters:

timezone - the TimeZone

locale - the Locale

GregorianCalendar

GregorianCalendar(boolean ignored)

Method Detail

add

public void add(int field,
                int value)

Adds the specified amount to a Calendar field.

Specified by:

add in class Calendar

Parameters:

field - the Calendar field to modify

value - the amount to add to the field

Throws:

IllegalArgumentException - when the specified field is DST_OFFSET or ZONE_OFFSET.

clone

public Object clone()

Creates new instance of GregorianCalendar with the same properties.

Overrides:

clone in class Calendar

Returns:

a shallow copy of this GregorianCalendar

See Also:

Cloneable

computeFields

protected void computeFields()

Computes the Calendar fields from the time.

Specified by:

computeFields in class Calendar

computeTime

protected void computeTime()

Computes the time from the Calendar fields.

Specified by:

computeTime in class Calendar

Throws:

IllegalArgumentException - when the time cannot be computed from the current field values

equals

public boolean equals(Object object)

Compares the specified object to this GregorianCalendar and answer if they are equal. The object must be an instance of GregorianCalendar and have the same properties.

Overrides:

equals in class Calendar

Parameters:

object - the object to compare with this object

Returns:

true if the specified object is equal to this GregorianCalendar, false otherwise

Throws:

IllegalArgumentException - when the time is not set and the time cannot be computed from the current field values

See Also:

hashCode()

getActualMaximum

public int getActualMaximum(int field)

Gets the maximum value of the specified field for the current date. For example, the maximum number of days in the current month.

Overrides:

getActualMaximum in class Calendar

Parameters:

field - the field

Returns:

the maximum value of the specified field

getActualMinimum

public int getActualMinimum(int field)

Gets the minimum value of the specified field for the current date. For the gregorian calendar, this value is the same as getMinimum().

Overrides:

getActualMinimum in class Calendar

Parameters:

field - the field

Returns:

the minimum value of the specified field

getGreatestMinimum

public int getGreatestMinimum(int field)

Gets the greatest minimum value of the specified field. For the gregorian calendar, this value is the same as getMinimum().

Specified by:

getGreatestMinimum in class Calendar

Parameters:

field - the field

Returns:

the greatest minimum value of the specified field

getGregorianChange

public final Date getGregorianChange()

Returns the gregorian change date of this calendar. This is the date on which the gregorian calendar came into effect.

Returns:

a Date which represents the gregorian change date

getLeastMaximum

public int getLeastMaximum(int field)

Gets the smallest maximum value of the specified field. For example, 28 for the day of month field.

Specified by:

getLeastMaximum in class Calendar

Parameters:

field - the field

Returns:

the smallest maximum value of the specified field

getMaximum

public int getMaximum(int field)

Gets the greatest maximum value of the specified field. For example, 31 for the day of month field.

Specified by:

getMaximum in class Calendar

Parameters:

field - the field

Returns:

the greatest maximum value of the specified field

getMinimum

public int getMinimum(int field)

Gets the smallest minimum value of the specified field.

Specified by:

getMinimum in class Calendar

Parameters:

field - the field

Returns:

the smallest minimum value of the specified field

getOffset

int getOffset(long localTime)

hashCode

public int hashCode()

Returns an integer hash code for the receiver. Objects which are equal answer the same value for this method.

Overrides:

hashCode in class Calendar

Returns:

the receiver's hash

See Also:

equals(java.lang.Object)

isLeapYear

public boolean isLeapYear(int year)

Returns if the specified year is a leap year.

Parameters:

year - the year

Returns:

true if the specified year is a leap year, false otherwise

roll

public void roll(int field,
                 int value)

Adds the specified amount the specified field and wrap the value of the field when it goes beyond the maximum or minimum value for the current date. Other fields will be adjusted as required to maintain a consistent date.

Overrides:

roll in class Calendar

Parameters:

field - the field to roll

value - the amount to add

Throws:

IllegalArgumentException - when an invalid field is specified

roll

public void roll(int field,
                 boolean increment)

Increment or decrement the specified field and wrap the value of the field when it goes beyond the maximum or minimum value for the current date. Other fields will be adjusted as required to maintain a consistent date. For example, March 31 will roll to April 30 when rolling the month field.

Specified by:

roll in class Calendar

Parameters:

field - the field to roll

increment - true to increment the field, false to decrement

Throws:

IllegalArgumentException - when an invalid field is specified

setGregorianChange

public void setGregorianChange(Date date)

Sets the gregorian change date of this calendar.

Parameters:

date - a Date which represents the gregorian change date

setFirstDayOfWeek

public void setFirstDayOfWeek(int value)

Description copied from class: Calendar

Sets the first day of the week for this Calendar.

Overrides:

setFirstDayOfWeek in class Calendar

Parameters:

value - a Calendar day of the week

setMinimalDaysInFirstWeek

public void setMinimalDaysInFirstWeek(int value)

Description copied from class: Calendar

Sets the minimal days in the first week of the year.

Overrides:

setMinimalDaysInFirstWeek in class Calendar

Parameters:

value - the minimal days in the first week of the year