java.util

Class Calendar

java.lang.Object

java.util.Calendar

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

GregorianCalendar

public abstract class Calendar
extends Object
implements Cloneable

Field Summary

Fields

Modifier and Type	Field and Description
static int	AM
static int	AM_PM
static int	APRIL
protected boolean	areFieldsSet
static int	AUGUST
static int	DATE
static int	DAY_OF_MONTH
static int	DAY_OF_WEEK
static int	DAY_OF_WEEK_IN_MONTH
static int	DAY_OF_YEAR
static int	DECEMBER
static int	DST_OFFSET
static int	ERA
static int	FEBRUARY
static int	FRIDAY
static int	HOUR
static int	HOUR_OF_DAY
protected boolean[]	isParamSet
protected boolean	isTimeSet
static int	JANUARY
static int	JULY
static int	JUNE
static int	MARCH
static int	MAY
static int	MILLISECOND
static int	MINUTE
static int	MONDAY
static int	MONTH
static int	NOVEMBER
static int	OCTOBER
static int	PARAM_COUNT
static int	PM
static int	SATURDAY
static int	SECOND
static int	SEPTEMBER
static int	SUNDAY
static int	THURSDAY
protected long	time
static int	TUESDAY
protected int[]	tzParams
static int	UNDECIMBER
static int	WEDNESDAY
static int	WEEK_OF_MONTH
static int	WEEK_OF_YEAR
static int	YEAR
static int	ZONE_OFFSET

Constructor Summary

Constructors

Constructor and Description
Calendar() Constructs a Calendar with the default time zone.
Calendar(TimeZone timezone) Constructs a calendar with the specified time zone.

Method Summary

Modifier and Type	Method and Description
abstract void	add(int field, int amount) Adds or subtracts the specified amount of time to the given calendar field, based on the calendar's rules.
abstract boolean	after(Object when) Returns whether this Calendar represents a time after the time represented by the specified Object.
abstract boolean	before(Object when) Returns whether this Calendar represents a time before the time represented by the specified Object.
void	clear() Sets all the calendar field values and the time value (millisecond offset from the Epoch) of this Calendar undefined.
void	clear(int field) Sets the given calendar field value and the time value (millisecond offset from the Epoch) of this Calendar undefined.
Object	clone() Creates a new object of the same class as this object.
protected void	complete() Fills in any unset tzParams in the calendar tzParams.
protected abstract void	computeFields() Converts the current millisecond time value time to calendar field values in tzParams[].
protected abstract void	computeTime() Converts the current calendar field values in tzParams[] to the millisecond time value time.
abstract boolean	equals(Object obj) Compares two Objects for equality.
int	get(int field) Returns the value of the given calendar field.
int	getFirstDayOfWeek() Gets what the first day of the week is; e.g., SUNDAY in the U.S., MONDAY in France.
abstract int	getGreatestMinimum(int field) Returns the highest minimum value for the given calendar field of this Calendar instance.
static Calendar	getInstance() Gets a calendar using the default time zone.
static Calendar	getInstance(TimeZone timezone) Gets a calendar using the specified time zone.
abstract int	getLeastMaximum(int field) Returns the lowest maximum value for the given calendar field of this Calendar instance.
abstract int	getMaximum(int field) Returns the maximum value for the given calendar field of this Calendar instance.
int	getMinimalDaysInFirstWeek() Gets what the minimal days required in the first week of the year are.
abstract int	getMinimum(int field) Returns the minimum value for the given calendar field of this Calendar instance.
Date	getTime() Returns a Date object representing this Calendar's time value (millisecond offset from the Epoch").
protected long	getTimeInMillis() Returns this Calendar's time value in milliseconds.
TimeZone	getTimeZone() Gets the time zone.
protected int	internalGet(int field) Returns the value of the given calendar field.
boolean	isLenient() Tells whether date/time interpretation is to be lenient.
boolean	isSet(int field) Determines if the given calendar field has a value set, including cases that the value has been set by internal tzParams calculations triggered by a get method call.
abstract void	roll(int field, boolean up) Adds or subtracts (up/down) a single unit of time on the given time field without changing larger tzParams.
void	set(int field, int value) Sets the given calendar field to the given value.
void	set(int year, int month, int day) Sets the values for the tzParams YEAR, MONTH, and DAY_OF_MONTH.
void	set(int year, int month, int day, int hours, int mins) Sets the values for the tzParams YEAR, MONTH, DAY_OF_MONTH, HOUR and MINUTE.
void	set(int year, int month, int day, int hours, int mins, int secs) Sets the values for the tzParams YEAR, MONTH, DAY_OF_MONTH, HOUR, MINUTE, and SECOND.
void	setFirstDayOfWeek(int dow) Sets what the first day of the week is.
void	setLenient(boolean flag) Specifies whether or not date/time interpretation is to be lenient.
void	setMinimalDaysInFirstWeek(int value) Sets what the minimal days required in the first week of the year are.
void	setTime(Date date) Sets this Calendar's time with the given Date.
void	setTimeInMillis(long ref) Sets this Calendar's current time from the given long value.
void	setTimeZone(TimeZone timezone) Sets the time zone with the given time zone value.

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PARAM_COUNT

public static final int PARAM_COUNT

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Constant Field Values

ERA

public static final int ERA

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Constant Field Values

YEAR

public static final int YEAR

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Constant Field Values

MONTH

public static final int MONTH

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Constant Field Values

WEEK_OF_YEAR

public static final int WEEK_OF_YEAR

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Constant Field Values

WEEK_OF_MONTH

public static final int WEEK_OF_MONTH

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Constant Field Values

DATE

public static final int DATE

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Constant Field Values

DAY_OF_MONTH

public static final int DAY_OF_MONTH

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Constant Field Values

DAY_OF_YEAR

public static final int DAY_OF_YEAR

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Constant Field Values

DAY_OF_WEEK

public static final int DAY_OF_WEEK

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Constant Field Values

DAY_OF_WEEK_IN_MONTH

public static final int DAY_OF_WEEK_IN_MONTH

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Constant Field Values

AM_PM

public static final int AM_PM

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Constant Field Values

HOUR

public static final int HOUR

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Constant Field Values

HOUR_OF_DAY

public static final int HOUR_OF_DAY

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Constant Field Values

MINUTE

public static final int MINUTE

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Constant Field Values

SECOND

public static final int SECOND

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Constant Field Values

MILLISECOND

public static final int MILLISECOND

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Constant Field Values

ZONE_OFFSET

public static final int ZONE_OFFSET

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Constant Field Values

DST_OFFSET

public static final int DST_OFFSET

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Constant Field Values

AM

public static final int AM

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Constant Field Values

PM

public static final int PM

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Constant Field Values

JANUARY

public static final int JANUARY

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Constant Field Values

FEBRUARY

public static final int FEBRUARY

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Constant Field Values

MARCH

public static final int MARCH

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Constant Field Values

APRIL

public static final int APRIL

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Constant Field Values

MAY

public static final int MAY

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JUNE

public static final int JUNE

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Constant Field Values

JULY

public static final int JULY

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Constant Field Values

AUGUST

public static final int AUGUST

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Constant Field Values

SEPTEMBER

public static final int SEPTEMBER

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OCTOBER

public static final int OCTOBER

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NOVEMBER

public static final int NOVEMBER

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DECEMBER

public static final int DECEMBER

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Constant Field Values

UNDECIMBER

public static final int UNDECIMBER

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Constant Field Values

SUNDAY

public static final int SUNDAY

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Constant Field Values

MONDAY

public static final int MONDAY

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Constant Field Values

TUESDAY

public static final int TUESDAY

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WEDNESDAY

public static final int WEDNESDAY

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Constant Field Values

THURSDAY

public static final int THURSDAY

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Constant Field Values

FRIDAY

public static final int FRIDAY

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SATURDAY

public static final int SATURDAY

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Constant Field Values

tzParams

protected int[] tzParams

isParamSet

protected boolean[] isParamSet

time

protected long time

isTimeSet

protected boolean isTimeSet

areFieldsSet

protected boolean areFieldsSet

Constructor Detail

Calendar

public Calendar()

Constructs a Calendar with the default time zone.

Calendar

public Calendar(TimeZone timezone)

Constructs a calendar with the specified time zone.

Parameters:

timezone - the time zone to use

Method Detail

add

public abstract void add(int field,
                         int amount)

Adds or subtracts the specified amount of time to the given calendar field, based on the calendar's rules.

Parameters:

field - the calendar field.

amount - the amount of date or time to be added to the field.

after

public abstract boolean after(Object when)

Returns whether this Calendar represents a time after the time represented by the specified Object.

Parameters:

when - the Object to be compared

Returns:

true if the time of this Calendar is after the time represented by when; false otherwise.

before

public abstract boolean before(Object when)

Returns whether this Calendar represents a time before the time represented by the specified Object.

Parameters:

when - the Object to be compared

Returns:

true if the time of this Calendar is before the time represented by when; false otherwise.

clear

public final void clear()

Sets all the calendar field values and the time value (millisecond offset from the Epoch) of this Calendar undefined.

clear

public final void clear(int field)

Sets the given calendar field value and the time value (millisecond offset from the Epoch) of this Calendar undefined.

Parameters:

field - the calendar field to be cleared.

clone

public Object clone()

Description copied from class: Object

Creates a new object of the same class as this object. It then initializes each of the new object's fields by assigning it the same value as the corresponding field in this object. No constructor is called.

The clone method of class Object will only clone an object whose class indicates that it is willing for its instances to be cloned. A class indicates that its instances can be cloned by declaring that it implements the Cloneable interface.

Overrides:

clone in class Object

Returns:

a clone of this instance.

See Also:

Cloneable

complete

protected void complete()

Fills in any unset tzParams in the calendar tzParams.

computeFields

protected abstract void computeFields()

Converts the current millisecond time value time to calendar field values in tzParams[].

computeTime

protected abstract void computeTime()

Converts the current calendar field values in tzParams[] to the millisecond time value time.

equals

public abstract boolean equals(Object obj)

Description copied from class: Object

Compares two Objects for equality.

The equals method implements an equivalence relation:

• It is reflexive: for any reference value x, x.equals(x) should return true.
• It is symmetric: for any reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false.
• For any reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any reference values x and y, this method returns true if and only if x and y refer to the same object (x==y has the value true).

Overrides:

equals in class Object

Parameters:

obj - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

Boolean.hashCode(), Hashtable

get

public final int get(int field)

Returns the value of the given calendar field.

Parameters:

field - the given calendar field

Returns:

the value for the given calendar field.

getFirstDayOfWeek

public int getFirstDayOfWeek()

Gets what the first day of the week is; e.g., SUNDAY in the U.S., MONDAY in France.

Returns:

the first day of the week.

getGreatestMinimum

public abstract int getGreatestMinimum(int field)

Returns the highest minimum value for the given calendar field of this Calendar instance.

Parameters:

field - the calendar field.

Returns:

the highest minimum value for the given calendar field.

getInstance

public static Calendar getInstance()

Gets a calendar using the default time zone.

Returns:

a Calendar.

getInstance

public static Calendar getInstance(TimeZone timezone)

Gets a calendar using the specified time zone.

Parameters:

timezone - the time zone to use

Returns:

a Calendar.

getLeastMaximum

public abstract int getLeastMaximum(int field)

Returns the lowest maximum value for the given calendar field of this Calendar instance.

Parameters:

field - the calendar field.

Returns:

the lowest maximum value for the given calendar field.

getMaximum

public abstract int getMaximum(int field)

Returns the maximum value for the given calendar field of this Calendar instance.

Parameters:

field - the calendar field.

Returns:

the maximum value for the given calendar field.

getMinimalDaysInFirstWeek

public int getMinimalDaysInFirstWeek()

Gets what the minimal days required in the first week of the year are.

Returns:

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

getMinimum

public abstract int getMinimum(int field)

Returns the minimum value for the given calendar field of this Calendar instance. The minimum value is defined as the smallest value returned by the get method for any possible time value.

Parameters:

field - the calendar field.

Returns:

the minimum value for the given calendar field.

getTime

public final Date getTime()

Returns a Date object representing this Calendar's time value (millisecond offset from the Epoch").

Returns:

a Date representing the time value.

getTimeInMillis

protected long getTimeInMillis()

Returns this Calendar's time value in milliseconds.

Returns:

the current time as UTC milliseconds from the epoch.

getTimeZone

public TimeZone getTimeZone()

Gets the time zone.

Returns:

the time zone object associated with this calendar.

internalGet

protected final int internalGet(int field)

Returns the value of the given calendar field. This method does not involve normalization or validation of the field value.

Parameters:

field - the given calendar field.

Returns:

the value for the given calendar field.

isLenient

public boolean isLenient()

Tells whether date/time interpretation is to be lenient.

Returns:

true if the interpretation mode of this calendar is lenient; false otherwise.

isSet

public final boolean isSet(int field)

Determines if the given calendar field has a value set, including cases that the value has been set by internal tzParams calculations triggered by a get method call.

Parameters:

field - the field of interest

Returns:

true if the given calendar field has a value set; false otherwise.

roll

public abstract void roll(int field,
                          boolean up)

Adds or subtracts (up/down) a single unit of time on the given time field without changing larger tzParams.

Parameters:

field - the time field.

up - indicates if the value of the specified time field is to be rolled up or rolled down. Use true if rolling up, false otherwise.

set

public final void set(int field,
                      int value)

Sets the given calendar field to the given value. The value is not interpreted by this method regardless of the leniency mode.

Parameters:

field - the given calendar field.

value - the value to be set for the given calendar field.

set

public final void set(int year,
                      int month,
                      int day)

Sets the values for the tzParams YEAR, MONTH, and DAY_OF_MONTH. Previous values of other tzParams are retained.

Parameters:

year - the value used to set the YEAR calendar field.

month - the value used to set the MONTH calendar field. Month value is 0-based. e.g., 0 for January.

day - the value used to set the DAY_OF_MONTH calendar field.

set

public final void set(int year,
                      int month,
                      int day,
                      int hours,
                      int mins)

Sets the values for the tzParams YEAR, MONTH, DAY_OF_MONTH, HOUR and MINUTE. Previous values of other tzParams are retained.

Parameters:

year - the value used to set the YEAR calendar field.

month - the value used to set the MONTH calendar field. Month value is 0-based. e.g., 0 for January.

day - the value used to set the DAY_OF_MONTH calendar field.

hours - the value used to set the HOUR_OF_DAY calendar field.

mins - the value used to set the MINUTE calendar field.

set

public final void set(int year,
                      int month,
                      int day,
                      int hours,
                      int mins,
                      int secs)

Sets the values for the tzParams YEAR, MONTH, DAY_OF_MONTH, HOUR, MINUTE, and SECOND. Previous values of other tzParams are retained.

Parameters:

year - the value used to set the YEAR calendar field.

month - the value used to set the MONTH calendar field. Month value is 0-based. e.g., 0 for January.

day - the value used to set the DAY_OF_MONTH calendar field.

hours - the value used to set the HOUR_OF_DAY calendar field.

mins - the value used to set the MINUTE calendar field.

secs - the value used to set the SECOND calendar field.

setFirstDayOfWeek

public void setFirstDayOfWeek(int dow)

Sets what the first day of the week is.

Parameters:

dow - the given first day of the week.

setLenient

public void setLenient(boolean flag)

Specifies whether or not date/time interpretation is to be lenient.

Parameters:

flag - true if the lenient mode is to be turned on; false if it is to be turned off.

setMinimalDaysInFirstWeek

public void setMinimalDaysInFirstWeek(int value)

Sets what the minimal days required in the first week of the year are.

Parameters:

value - the given minimal days required in the first week of the year.

setTime

public final void setTime(Date date)

Sets this Calendar's time with the given Date.

Parameters:

date - the given Date.

setTimeInMillis

public void setTimeInMillis(long ref)

Sets this Calendar's current time from the given long value.

Parameters:

ref - the new time in UTC milliseconds from the epoch.

setTimeZone

public void setTimeZone(TimeZone timezone)

Sets the time zone with the given time zone value.

Parameters:

timezone - the given time zone.