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java.util
Class Calendar
java.lang.Objectjava.util.Calendar
- All Implemented Interfaces:
- Serializable, Cloneable, Comparable<Calendar>
- Direct Known Subclasses:
- GregorianCalendar
public abstract class Calendar
- extends Object
- implements Serializable, Cloneable, Comparable<Calendar>
- extends Object
The Calendar
class is an abstract class that provides methods
for converting between a specific instant in time and a set of calendar fields
such as YEAR
, MONTH
,
DAY_OF_MONTH
, HOUR
, and so on, and for
manipulating the calendar fields, such as getting the date of the next
week. An instant in time can be represented by a millisecond value that is
an offset from the Epoch, January 1, 1970
00:00:00.000 GMT (Gregorian).
The class also provides additional fields and methods for
implementing a concrete calendar system outside the package. Those
fields and methods are defined as protected
.
Like other locale-sensitive classes, Calendar
provides a
class method, getInstance
, for getting a generally useful
object of this type. Calendar
's getInstance
method
returns a Calendar
object whose
calendar fields have been initialized with the current date and time:
Calendar rightNow = Calendar.getInstance();
A Calendar
object can produce all the calendar field values
needed to implement the date-time formatting for a particular language and
calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
Calendar
defines the range of values returned by
certain calendar fields, as well as their meaning. For example,
the first month of the calendar system has value MONTH ==
JANUARY
for all calendars. Other values are defined by the
concrete subclass, such as ERA
. See individual field
documentation and subclass documentation for details.
Getting and Setting Calendar Field Values
The calendar field values can be set by calling the set
methods. Any field values set in a Calendar
will not be
interpreted until it needs to calculate its time value (milliseconds from
the Epoch) or values of the calendar fields. Calling the
get
, getTimeInMillis
, getTime
,
add
and roll
involves such calculation.
Leniency
Calendar
has two modes for interpreting the calendar
fields, lenient and non-lenient. When a
Calendar
is in lenient mode, it accepts a wider range of
calendar field values than it produces. When a Calendar
recomputes calendar field values for return by get()
, all of
the calendar fields are normalized. For example, a lenient
GregorianCalendar
interprets MONTH == JANUARY
,
DAY_OF_MONTH == 32
as February 1.
When a Calendar
is in non-lenient mode, it throws an
exception if there is any inconsistency in its calendar fields. For
example, a GregorianCalendar
always produces
DAY_OF_MONTH
values between 1 and the length of the month. A
non-lenient GregorianCalendar
throws an exception upon
calculating its time or calendar field values if any out-of-range field
value has been set.
First Week
Calendar
defines a locale-specific seven day week using two
parameters: the first day of the week and the minimal days in first week
(from 1 to 7). These numbers are taken from the locale resource data when a
Calendar
is constructed. They may also be specified explicitly
through the methods for setting their values.
When setting or getting the WEEK_OF_MONTH
or
WEEK_OF_YEAR
fields, Calendar
must determine the
first week of the month or year as a reference point. The first week of a
month or year is defined as the earliest seven day period beginning on
getFirstDayOfWeek()
and containing at least
getMinimalDaysInFirstWeek()
days of that month or year. Weeks
numbered ..., -1, 0 precede the first week; weeks numbered 2, 3,... follow
it. Note that the normalized numbering returned by get()
may be
different. For example, a specific Calendar
subclass may
designate the week before week 1 of a year as week n
of
the previous year.
Calendar Fields Resolution
When computing a date and time from the calendar fields, there may be insufficient information for the computation (such as only year and month with no day of month), or there may be inconsistent information (such as Tuesday, July 15, 1996 (Gregorian) -- July 15, 1996 is actually a Monday).Calendar
will resolve
calendar field values to determine the date and time in the
following way.
If there is any conflict in calendar field values,
Calendar
gives priorities to calendar fields that have been set
more recently. The following are the default combinations of the
calendar fields. The most recent combination, as determined by the
most recently set single field, will be used.
For the time of day fields:YEAR + MONTH + DAY_OF_MONTH YEAR + MONTH + WEEK_OF_MONTH + DAY_OF_WEEK YEAR + MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK YEAR + DAY_OF_YEAR YEAR + DAY_OF_WEEK + WEEK_OF_YEAR
HOUR_OF_DAY AM_PM + HOUR
If there are any calendar fields whose values haven't been set in the selected
field combination, Calendar
uses their default values. The default
value of each field may vary by concrete calendar systems. For example, in
GregorianCalendar
, the default of a field is the same as that
of the start of the Epoch: i.e., YEAR = 1970
, MONTH =
JANUARY
, DAY_OF_MONTH = 1
, etc.
Note: There are certain possible ambiguities in interpretation of certain singular times, which are resolved in the following ways:
- 23:59 is the last minute of the day and 00:00 is the first minute of the next day. Thus, 23:59 on Dec 31, 1999 < 00:00 on Jan 1, 2000 < 00:01 on Jan 1, 2000.
- Although historically not precise, midnight also belongs to "am", and noon belongs to "pm", so on the same day, 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
The date or time format strings are not part of the definition of a
calendar, as those must be modifiable or overridable by the user at
runtime. Use DateFormat
to format dates.
Field Manipulation
The calendar fields can be changed using three methods:set()
, add()
, and roll()
.
set(f, value)
changes calendar field
f
to value
. In addition, it sets an
internal member variable to indicate that calendar field f
has
been changed. Although calendar field f
is changed immediately,
the calendar's time value in milliseconds is not recomputed until the next call to
get()
, getTime()
, getTimeInMillis()
,
add()
, or roll()
is made. Thus, multiple calls to
set()
do not trigger multiple, unnecessary
computations. As a result of changing a calendar field using
set()
, other calendar fields may also change, depending on the
calendar field, the calendar field value, and the calendar system. In addition,
get(f)
will not necessarily return value
set by
the call to the set
method
after the calendar fields have been recomputed. The specifics are determined by
the concrete calendar class.
Example: Consider a GregorianCalendar
originally set to August 31, 1999. Calling set(Calendar.MONTH,
Calendar.SEPTEMBER)
sets the date to September 31,
1999. This is a temporary internal representation that resolves to
October 1, 1999 if getTime()
is then called. However, a
call to set(Calendar.DAY_OF_MONTH, 30)
before the call to
getTime()
sets the date to September 30, 1999, since
no recomputation occurs after set()
itself.
add(f, delta)
adds delta
to field f
. This is equivalent to calling set(f,
get(f) + delta)
with two adjustments:
Add rule 1. The value of field
f
after the call minus the value of fieldf
before the call isdelta
, modulo any overflow that has occurred in fieldf
. Overflow occurs when a field value exceeds its range and, as a result, the next larger field is incremented or decremented and the field value is adjusted back into its range.Add rule 2. If a smaller field is expected to be invariant, but it is impossible for it to be equal to its prior value because of changes in its minimum or maximum after field
f
is changed or other constraints, such as time zone offset changes, then its value is adjusted to be as close as possible to its expected value. A smaller field represents a smaller unit of time.HOUR
is a smaller field thanDAY_OF_MONTH
. No adjustment is made to smaller fields that are not expected to be invariant. The calendar system determines what fields are expected to be invariant.
In addition, unlike set()
, add()
forces
an immediate recomputation of the calendar's milliseconds and all
fields.
Example: Consider a GregorianCalendar
originally set to August 31, 1999. Calling add(Calendar.MONTH,
13)
sets the calendar to September 30, 2000. Add rule
1 sets the MONTH
field to September, since
adding 13 months to August gives September of the next year. Since
DAY_OF_MONTH
cannot be 31 in September in a
GregorianCalendar
, add rule 2 sets the
DAY_OF_MONTH
to 30, the closest possible value. Although
it is a smaller field, DAY_OF_WEEK
is not adjusted by
rule 2, since it is expected to change when the month changes in a
GregorianCalendar
.
roll(f, delta)
adds
delta
to field f
without changing larger
fields. This is equivalent to calling add(f, delta)
with
the following adjustment:
Roll rule. Larger fields are unchanged after the call. A larger field represents a larger unit of time.
DAY_OF_MONTH
is a larger field thanHOUR
.
Example: See GregorianCalendar.roll(int, int)
.
Usage model. To motivate the behavior of
add()
and roll()
, consider a user interface
component with increment and decrement buttons for the month, day, and
year, and an underlying GregorianCalendar
. If the
interface reads January 31, 1999 and the user presses the month
increment button, what should it read? If the underlying
implementation uses set()
, it might read March 3, 1999. A
better result would be February 28, 1999. Furthermore, if the user
presses the month increment button again, it should read March 31,
1999, not March 28, 1999. By saving the original date and using either
add()
or roll()
, depending on whether larger
fields should be affected, the user interface can behave as most users
will intuitively expect.
- Since:
- JDK1.1
- See Also:
System.currentTimeMillis()
,Date
,GregorianCalendar
,TimeZone
,DateFormat
, Serialized Form
Field Summary | |
---|---|
static int |
ALL_STYLES
A style specifier for getDisplayNames indicating names in all styles, such as
"January" and "Jan". |
static int |
AM
Value of the AM_PM field indicating the
period of the day from midnight to just before noon. |
static int |
AM_PM
Field number for get and set indicating
whether the HOUR is before or after noon. |
static int |
APRIL
Value of the MONTH field indicating the
fourth month of the year in the Gregorian and Julian calendars. |
protected boolean |
areFieldsSet
True if fields[] are in sync with the currently set time. |
static int |
AUGUST
Value of the MONTH field indicating the
eighth month of the year in the Gregorian and Julian calendars. |
static int |
DATE
Field number for get and set indicating the
day of the month. |
static int |
DAY_OF_MONTH
Field number for get and set indicating the
day of the month. |
static int |
DAY_OF_WEEK
Field number for get and set indicating the day
of the week. |
static int |
DAY_OF_WEEK_IN_MONTH
Field number for get and set indicating the
ordinal number of the day of the week within the current month. |
static int |
DAY_OF_YEAR
Field number for get and set indicating the day
number within the current year. |
static int |
DECEMBER
Value of the MONTH field indicating the
twelfth month of the year in the Gregorian and Julian calendars. |
static int |
DST_OFFSET
Field number for get and set indicating the
daylight savings offset in milliseconds. |
static int |
ERA
Field number for get and set indicating the
era, e.g., AD or BC in the Julian calendar. |
static int |
FEBRUARY
Value of the MONTH field indicating the
second month of the year in the Gregorian and Julian calendars. |
static int |
FIELD_COUNT
The number of distinct fields recognized by get and set . |
protected int[] |
fields
The calendar field values for the currently set time for this calendar. |
static int |
FRIDAY
Value of the DAY_OF_WEEK field indicating
Friday. |
static int |
HOUR
Field number for get and set indicating the
hour of the morning or afternoon. |
static int |
HOUR_OF_DAY
Field number for get and set indicating the
hour of the day. |
protected boolean[] |
isSet
The flags which tell if a specified calendar field for the calendar is set. |
protected boolean |
isTimeSet
True if then the value of time is valid. |
static int |
JANUARY
Value of the MONTH field indicating the
first month of the year in the Gregorian and Julian calendars. |
static int |
JULY
Value of the MONTH field indicating the
seventh month of the year in the Gregorian and Julian calendars. |
static int |
JUNE
Value of the MONTH field indicating the
sixth month of the year in the Gregorian and Julian calendars. |
static int |
LONG
A style specifier for getDisplayName and getDisplayNames indicating a long name, such as "January". |
static int |
MARCH
Value of the MONTH field indicating the
third month of the year in the Gregorian and Julian calendars. |
static int |
MAY
Value of the MONTH field indicating the
fifth month of the year in the Gregorian and Julian calendars. |
static int |
MILLISECOND
Field number for get and set indicating the
millisecond within the second. |
static int |
MINUTE
Field number for get and set indicating the
minute within the hour. |
static int |
MONDAY
Value of the DAY_OF_WEEK field indicating
Monday. |
static int |
MONTH
Field number for get and set indicating the
month. |
static int |
NOVEMBER
Value of the MONTH field indicating the
eleventh month of the year in the Gregorian and Julian calendars. |
static int |
OCTOBER
Value of the MONTH field indicating the
tenth month of the year in the Gregorian and Julian calendars. |
static int |
PM
Value of the AM_PM field indicating the
period of the day from noon to just before midnight. |
static int |
SATURDAY
Value of the DAY_OF_WEEK field indicating
Saturday. |
static int |
SECOND
Field number for get and set indicating the
second within the minute. |
static int |
SEPTEMBER
Value of the MONTH field indicating the
ninth month of the year in the Gregorian and Julian calendars. |
static int |
SHORT
A style specifier for getDisplayName and getDisplayNames indicating a short name, such as "Jan". |
static int |
SUNDAY
Value of the DAY_OF_WEEK field indicating
Sunday. |
static int |
THURSDAY
Value of the DAY_OF_WEEK field indicating
Thursday. |
protected long |
time
The currently set time for this calendar, expressed in milliseconds after January 1, 1970, 0:00:00 GMT. |
static int |
TUESDAY
Value of the DAY_OF_WEEK field indicating
Tuesday. |
static int |
UNDECIMBER
Value of the MONTH field indicating the
thirteenth month of the year. |
static int |
WEDNESDAY
Value of the DAY_OF_WEEK field indicating
Wednesday. |
static int |
WEEK_OF_MONTH
Field number for get and set indicating the
week number within the current month. |
static int |
WEEK_OF_YEAR
Field number for get and set indicating the
week number within the current year. |
static int |
YEAR
Field number for get and set indicating the
year. |
static int |
ZONE_OFFSET
Field number for get and set
indicating the raw offset from GMT in milliseconds. |
Constructor Summary | |
---|---|
protected |
Calendar()
Constructs a Calendar with the default time zone and locale. |
protected |
Calendar(TimeZone zone,
Locale aLocale)
Constructs a calendar with the specified time zone and locale. |
Method Summary | |
---|---|
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. |
boolean |
after(Object when)
Returns whether this Calendar represents a time
after the time represented by the specified
Object . |
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 and returns a copy of this object. |
int |
compareTo(Calendar anotherCalendar)
Compares the time values (millisecond offsets from the Epoch) represented by two Calendar objects. |
protected void |
complete()
Fills in any unset fields in the calendar fields. |
protected abstract void |
computeFields()
Converts the current millisecond time value time
to calendar field values in fields[] . |
protected abstract void |
computeTime()
Converts the current calendar field values in fields[]
to the millisecond time value
time . |
boolean |
equals(Object obj)
Compares this Calendar to the specified
Object . |
int |
get(int field)
Returns the value of the given calendar field. |
int |
getActualMaximum(int field)
Returns the maximum value that the specified calendar field could have, given the time value of this Calendar . |
int |
getActualMinimum(int field)
Returns the minimum value that the specified calendar field could have, given the time value of this Calendar . |
static Locale[] |
getAvailableLocales()
Returns an array of all locales for which the getInstance
methods of this class can return localized instances. |
String |
getDisplayName(int field,
int style,
Locale locale)
Returns the string representation of the calendar field value in the given style and
locale . |
Map<String,Integer> |
getDisplayNames(int field,
int style,
Locale locale)
Returns a Map containing all names of the calendar
field in the given style and
locale and their corresponding field values. |
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 and locale. |
static Calendar |
getInstance(Locale aLocale)
Gets a calendar using the default time zone and specified locale. |
static Calendar |
getInstance(TimeZone zone)
Gets a calendar using the specified time zone and default locale. |
static Calendar |
getInstance(TimeZone zone,
Locale aLocale)
Gets a calendar with the specified time zone and locale. |
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; e.g., if the first week is defined as one that contains the first day of the first month of a year, this method returns 1. |
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"). |
long |
getTimeInMillis()
Returns this Calendar's time value in milliseconds. |
TimeZone |
getTimeZone()
Gets the time zone. |
int |
hashCode()
Returns a hash code for this calendar. |
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 fields 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 fields. |
void |
roll(int field,
int amount)
Adds the specified (signed) amount to the specified calendar field without changing larger fields. |
void |
set(int field,
int value)
Sets the given calendar field to the given value. |
void |
set(int year,
int month,
int date)
Sets the values for the calendar fields YEAR ,
MONTH , and DAY_OF_MONTH . |
void |
set(int year,
int month,
int date,
int hourOfDay,
int minute)
Sets the values for the calendar fields YEAR ,
MONTH , DAY_OF_MONTH ,
HOUR_OF_DAY , and MINUTE . |
void |
set(int year,
int month,
int date,
int hourOfDay,
int minute,
int second)
Sets the values for the fields YEAR , MONTH ,
DAY_OF_MONTH , HOUR , MINUTE , and
SECOND . |
void |
setFirstDayOfWeek(int value)
Sets what the first day of the week is; e.g., SUNDAY in the U.S.,
MONDAY in France. |
void |
setLenient(boolean lenient)
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; For example, if the first week is defined as one that contains the first day of the first month of a year, call this method with value 1. |
void |
setTime(Date date)
Sets this Calendar's time with the given Date . |
void |
setTimeInMillis(long millis)
Sets this Calendar's current time from the given long value. |
void |
setTimeZone(TimeZone value)
Sets the time zone with the given time zone value. |
String |
toString()
Return a string representation of this calendar. |
Methods inherited from class java.lang.Object |
---|
finalize, getClass, notify, notifyAll, wait, wait, wait |
Field Detail |
---|
ERA
public static final int ERA
- Field number for
get
andset
indicating the era, e.g., AD or BC in the Julian calendar. This is a calendar-specific value; see subclass documentation.
YEAR
public static final int YEAR
- Field number for
get
andset
indicating the year. This is a calendar-specific value; see subclass documentation.- See Also:
- Constant Field Values
MONTH
public static final int MONTH
- Field number for
get
andset
indicating the month. This is a calendar-specific value. The first month of the year in the Gregorian and Julian calendars isJANUARY
which is 0; the last depends on the number of months in a year.
WEEK_OF_YEAR
public static final int WEEK_OF_YEAR
- Field number for
get
andset
indicating the week number within the current year. The first week of the year, as defined bygetFirstDayOfWeek()
andgetMinimalDaysInFirstWeek()
, has value 1. Subclasses define the value ofWEEK_OF_YEAR
for days before the first week of the year.
WEEK_OF_MONTH
public static final int WEEK_OF_MONTH
- Field number for
get
andset
indicating the week number within the current month. The first week of the month, as defined bygetFirstDayOfWeek()
andgetMinimalDaysInFirstWeek()
, has value 1. Subclasses define the value ofWEEK_OF_MONTH
for days before the first week of the month.
DATE
public static final int DATE
- Field number for
get
andset
indicating the day of the month. This is a synonym forDAY_OF_MONTH
. The first day of the month has value 1.- See Also:
DAY_OF_MONTH
, Constant Field Values
DAY_OF_MONTH
public static final int DAY_OF_MONTH
- Field number for
get
andset
indicating the day of the month. This is a synonym forDATE
. The first day of the month has value 1.- See Also:
DATE
, Constant Field Values
DAY_OF_YEAR
public static final int DAY_OF_YEAR
- Field number for
get
andset
indicating the day number within the current year. The first day of the year has value 1.- See Also:
- Constant Field Values
DAY_OF_WEEK
public static final int DAY_OF_WEEK
- Field number for
get
andset
indicating the day of the week. This field takes valuesSUNDAY
,MONDAY
,TUESDAY
,WEDNESDAY
,THURSDAY
,FRIDAY
, andSATURDAY
.
DAY_OF_WEEK_IN_MONTH
public static final int DAY_OF_WEEK_IN_MONTH
- Field number for
get
andset
indicating the ordinal number of the day of the week within the current month. Together with theDAY_OF_WEEK
field, this uniquely specifies a day within a month. UnlikeWEEK_OF_MONTH
andWEEK_OF_YEAR
, this field's value does not depend ongetFirstDayOfWeek()
orgetMinimalDaysInFirstWeek()
.DAY_OF_MONTH 1
through7
always correspond toDAY_OF_WEEK_IN_MONTH 1
;8
through14
correspond toDAY_OF_WEEK_IN_MONTH 2
, and so on.DAY_OF_WEEK_IN_MONTH 0
indicates the week beforeDAY_OF_WEEK_IN_MONTH 1
. Negative values count back from the end of the month, so the last Sunday of a month is specified asDAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1
. Because negative values count backward they will usually be aligned differently within the month than positive values. For example, if a month has 31 days,DAY_OF_WEEK_IN_MONTH -1
will overlapDAY_OF_WEEK_IN_MONTH 5
and the end of4
.- See Also:
DAY_OF_WEEK
,WEEK_OF_MONTH
, Constant Field Values
AM_PM
public static final int AM_PM
- Field number for
get
andset
indicating whether theHOUR
is before or after noon. E.g., at 10:04:15.250 PM theAM_PM
isPM
.- See Also:
AM
,PM
,HOUR
, Constant Field Values
HOUR
public static final int HOUR
- Field number for
get
andset
indicating the hour of the morning or afternoon.HOUR
is used for the 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12. E.g., at 10:04:15.250 PM theHOUR
is 10.- See Also:
AM_PM
,HOUR_OF_DAY
, Constant Field Values
HOUR_OF_DAY
public static final int HOUR_OF_DAY
- Field number for
get
andset
indicating the hour of the day.HOUR_OF_DAY
is used for the 24-hour clock. E.g., at 10:04:15.250 PM theHOUR_OF_DAY
is 22.- See Also:
HOUR
, Constant Field Values
MINUTE
public static final int MINUTE
- Field number for
get
andset
indicating the minute within the hour. E.g., at 10:04:15.250 PM theMINUTE
is 4.- See Also:
- Constant Field Values
SECOND
public static final int SECOND
- Field number for
get
andset
indicating the second within the minute. E.g., at 10:04:15.250 PM theSECOND
is 15.- See Also:
- Constant Field Values
MILLISECOND
public static final int MILLISECOND
- Field number for
get
andset
indicating the millisecond within the second. E.g., at 10:04:15.250 PM theMILLISECOND
is 250.- See Also:
- Constant Field Values
ZONE_OFFSET
public static final int ZONE_OFFSET
- Field number for
get
andset
indicating the raw offset from GMT in milliseconds.This field reflects the correct GMT offset value of the time zone of this
Calendar
if theTimeZone
implementation subclass supports historical GMT offset changes.- See Also:
- Constant Field Values
DST_OFFSET
public static final int DST_OFFSET
- Field number for
get
andset
indicating the daylight savings offset in milliseconds.This field reflects the correct daylight saving offset value of the time zone of this
Calendar
if theTimeZone
implementation subclass supports historical Daylight Saving Time schedule changes.- See Also:
- Constant Field Values
FIELD_COUNT
public static final int FIELD_COUNT
- The number of distinct fields recognized by
get
andset
. Field numbers range from0..FIELD_COUNT-1
.- See Also:
- Constant Field Values
SUNDAY
public static final int SUNDAY
- Value of the
DAY_OF_WEEK
field indicating Sunday.- See Also:
- Constant Field Values
MONDAY
public static final int MONDAY
- Value of the
DAY_OF_WEEK
field indicating Monday.- See Also:
- Constant Field Values
TUESDAY
public static final int TUESDAY
- Value of the
DAY_OF_WEEK
field indicating Tuesday.- See Also:
- Constant Field Values
WEDNESDAY
public static final int WEDNESDAY
- Value of the
DAY_OF_WEEK
field indicating Wednesday.- See Also:
- Constant Field Values
THURSDAY
public static final int THURSDAY
- Value of the
DAY_OF_WEEK
field indicating Thursday.- See Also:
- Constant Field Values
FRIDAY
public static final int FRIDAY
- Value of the
DAY_OF_WEEK
field indicating Friday.- See Also:
- Constant Field Values
SATURDAY
public static final int SATURDAY
- Value of the
DAY_OF_WEEK
field indicating Saturday.- See Also:
- Constant Field Values
JANUARY
public static final int JANUARY
- Value of the
MONTH
field indicating the first month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
FEBRUARY
public static final int FEBRUARY
- Value of the
MONTH
field indicating the second month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
MARCH
public static final int MARCH
- Value of the
MONTH
field indicating the third month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
APRIL
public static final int APRIL
- Value of the
MONTH
field indicating the fourth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
MAY
public static final int MAY
- Value of the
MONTH
field indicating the fifth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
JUNE
public static final int JUNE
- Value of the
MONTH
field indicating the sixth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
JULY
public static final int JULY
- Value of the
MONTH
field indicating the seventh month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
AUGUST
public static final int AUGUST
- Value of the
MONTH
field indicating the eighth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
SEPTEMBER
public static final int SEPTEMBER
- Value of the
MONTH
field indicating the ninth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
OCTOBER
public static final int OCTOBER
- Value of the
MONTH
field indicating the tenth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
NOVEMBER
public static final int NOVEMBER
- Value of the
MONTH
field indicating the eleventh month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
DECEMBER
public static final int DECEMBER
- Value of the
MONTH
field indicating the twelfth month of the year in the Gregorian and Julian calendars.- See Also:
- Constant Field Values
UNDECIMBER
public static final int UNDECIMBER
- Value of the
MONTH
field indicating the thirteenth month of the year. AlthoughGregorianCalendar
does not use this value, lunar calendars do.- See Also:
- Constant Field Values
AM
public static final int AM
- Value of the
AM_PM
field indicating the period of the day from midnight to just before noon.- See Also:
- Constant Field Values
PM
public static final int PM
- Value of the
AM_PM
field indicating the period of the day from noon to just before midnight.- See Also:
- Constant Field Values
ALL_STYLES
public static final int ALL_STYLES
- A style specifier for
getDisplayNames
indicating names in all styles, such as "January" and "Jan".- Since:
- 1.6
- See Also:
SHORT
,LONG
, Constant Field Values
SHORT
public static final int SHORT
- A style specifier for
getDisplayName
andgetDisplayNames
indicating a short name, such as "Jan".- Since:
- 1.6
- See Also:
LONG
, Constant Field Values
LONG
public static final int LONG
- A style specifier for
getDisplayName
andgetDisplayNames
indicating a long name, such as "January".- Since:
- 1.6
- See Also:
SHORT
, Constant Field Values
fields
protected int[] fields
- The calendar field values for the currently set time for this calendar.
This is an array of
FIELD_COUNT
integers, with index valuesERA
throughDST_OFFSET
.
isSet
protected boolean[] isSet
- The flags which tell if a specified calendar field for the calendar is set.
A new object has no fields set. After the first call to a method
which generates the fields, they all remain set after that.
This is an array of
FIELD_COUNT
booleans, with index valuesERA
throughDST_OFFSET
.
time
protected long time
- The currently set time for this calendar, expressed in milliseconds after
January 1, 1970, 0:00:00 GMT.
- See Also:
isTimeSet
isTimeSet
protected boolean isTimeSet
- True if then the value of
time
is valid. The time is made invalid by a change to an item offield[]
.- See Also:
time
areFieldsSet
protected boolean areFieldsSet
- True if
fields[]
are in sync with the currently set time. If false, then the next attempt to get the value of a field will force a recomputation of all fields from the current value oftime
.
Constructor Detail |
---|
Calendar
protected Calendar()
- Constructs a Calendar with the default time zone
and locale.
- See Also:
TimeZone.getDefault()
Calendar
protected Calendar(TimeZone zone, Locale aLocale)
- Constructs a calendar with the specified time zone and locale.
- Parameters:
zone
- the time zone to useaLocale
- the locale for the week data
Method Detail |
---|
getInstance
public static Calendar getInstance()
- Gets a calendar using the default time zone and locale. The
Calendar
returned is based on the current time in the default time zone with the default locale.- Returns:
- a Calendar.
getInstance
public static Calendar getInstance(TimeZone zone)
- Gets a calendar using the specified time zone and default locale.
The
Calendar
returned is based on the current time in the given time zone with the default locale.- Parameters:
zone
- the time zone to use- Returns:
- a Calendar.
getInstance
public static Calendar getInstance(Locale aLocale)
- Gets a calendar using the default time zone and specified locale.
The
Calendar
returned is based on the current time in the default time zone with the given locale.- Parameters:
aLocale
- the locale for the week data- Returns:
- a Calendar.
getInstance
public static Calendar getInstance(TimeZone zone, Locale aLocale)
- Gets a calendar with the specified time zone and locale.
The
Calendar
returned is based on the current time in the given time zone with the given locale.- Parameters:
zone
- the time zone to useaLocale
- the locale for the week data- Returns:
- a Calendar.
getAvailableLocales
public static Locale[] getAvailableLocales()
- Returns an array of all locales for which the
getInstance
methods of this class can return localized instances. The array returned must contain at least aLocale
instance equal toLocale.US
.- Returns:
- An array of locales for which localized
Calendar
instances are available.
computeTime
protected abstract void computeTime()
- Converts the current calendar field values in
fields[]
to the millisecond time valuetime
.- See Also:
complete()
,computeFields()
computeFields
protected abstract void computeFields()
- Converts the current millisecond time value
time
to calendar field values infields[]
. This allows you to sync up the calendar field values with a new time that is set for the calendar. The time is not recomputed first; to recompute the time, then the fields, call thecomplete()
method.- See Also:
computeTime()
getTime
public final Date getTime()
- Returns a
Date
object representing thisCalendar
's time value (millisecond offset from the Epoch").- Returns:
- a
Date
representing the time value. - See Also:
setTime(Date)
,getTimeInMillis()
setTime
public final void setTime(Date date)
- Sets this Calendar's time with the given
Date
.Note: Calling
setTime()
withDate(Long.MAX_VALUE)
orDate(Long.MIN_VALUE)
may yield incorrect field values fromget()
.- Parameters:
date
- the given Date.- See Also:
getTime()
,setTimeInMillis(long)
getTimeInMillis
public long getTimeInMillis()
- Returns this Calendar's time value in milliseconds.
- Returns:
- the current time as UTC milliseconds from the epoch.
- See Also:
getTime()
,setTimeInMillis(long)
setTimeInMillis
public void setTimeInMillis(long millis)
- Sets this Calendar's current time from the given long value.
- Parameters:
millis
- the new time in UTC milliseconds from the epoch.- See Also:
setTime(Date)
,getTimeInMillis()
get
public int get(int field)
- Returns the value of the given calendar field. In lenient mode,
all calendar fields are normalized. In non-lenient mode, all
calendar fields are validated and this method throws an
exception if any calendar fields have out-of-range values. The
normalization and validation are handled by the
complete()
method, which process is calendar system dependent.- Parameters:
field
- the given calendar field.- Returns:
- the value for the given calendar field.
- Throws:
ArrayIndexOutOfBoundsException
- if the specified field is out of range (field < 0 || field >= FIELD_COUNT
).- See Also:
set(int,int)
,complete()
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.
- See Also:
get(int)
set
public 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.- Throws:
ArrayIndexOutOfBoundsException
- if the specified field is out of range (field < 0 || field >= FIELD_COUNT
). in non-lenient mode.- See Also:
set(int,int,int)
,set(int,int,int,int,int)
,set(int,int,int,int,int,int)
,get(int)
set
public final void set(int year, int month, int date)
- Sets the values for the calendar fields
YEAR
,MONTH
, andDAY_OF_MONTH
. Previous values of other calendar fields are retained. If this is not desired, callclear()
first.- Parameters:
year
- the value used to set theYEAR
calendar field.month
- the value used to set theMONTH
calendar field. Month value is 0-based. e.g., 0 for January.date
- the value used to set theDAY_OF_MONTH
calendar field.- See Also:
set(int,int)
,set(int,int,int,int,int)
,set(int,int,int,int,int,int)
set
public final void set(int year, int month, int date, int hourOfDay, int minute)
- Sets the values for the calendar fields
YEAR
,MONTH
,DAY_OF_MONTH
,HOUR_OF_DAY
, andMINUTE
. Previous values of other fields are retained. If this is not desired, callclear()
first.- Parameters:
year
- the value used to set theYEAR
calendar field.month
- the value used to set theMONTH
calendar field. Month value is 0-based. e.g., 0 for January.date
- the value used to set theDAY_OF_MONTH
calendar field.hourOfDay
- the value used to set theHOUR_OF_DAY
calendar field.minute
- the value used to set theMINUTE
calendar field.- See Also:
set(int,int)
,set(int,int,int)
,set(int,int,int,int,int,int)
set
public final void set(int year, int month, int date, int hourOfDay, int minute, int second)
- Sets the values for the fields
YEAR
,MONTH
,DAY_OF_MONTH
,HOUR
,MINUTE
, andSECOND
. Previous values of other fields are retained. If this is not desired, callclear()
first.- Parameters:
year
- the value used to set theYEAR
calendar field.month
- the value used to set theMONTH
calendar field. Month value is 0-based. e.g., 0 for January.date
- the value used to set theDAY_OF_MONTH
calendar field.hourOfDay
- the value used to set theHOUR_OF_DAY
calendar field.minute
- the value used to set theMINUTE
calendar field.second
- the value used to set theSECOND
calendar field.- See Also:
set(int,int)
,set(int,int,int)
,set(int,int,int,int,int)
clear
public final void clear()
- Sets all the calendar field values and the time value
(millisecond offset from the Epoch) of
this
Calendar
undefined. This means thatisSet()
will returnfalse
for all the calendar fields, and the date and time calculations will treat the fields as if they had never been set. ACalendar
implementation class may use its specific default field values for date/time calculations. For example,GregorianCalendar
uses 1970 if theYEAR
field value is undefined.- See Also:
clear(int)
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. This means thatisSet(field)
will returnfalse
, and the date and time calculations will treat the field as if it had never been set. ACalendar
implementation class may use the field's specific default value for date and time calculations.The
HOUR_OF_DAY
,HOUR
andAM_PM
fields are handled independently and the the resolution rule for the time of day is applied. Clearing one of the fields doesn't reset the hour of day value of thisCalendar
. Useset(Calendar.HOUR_OF_DAY, 0)
to reset the hour value.- Parameters:
field
- the calendar field to be cleared.- See Also:
clear()
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 fields
calculations triggered by a
get
method call.- Returns:
true
if the given calendar field has a value set;false
otherwise.
getDisplayName
public String getDisplayName(int field, int style, Locale locale)
- Returns the string representation of the calendar
field
value in the givenstyle
andlocale
. If no string representation is applicable,null
is returned. This method callsget(field)
to get the calendarfield
value if the string representation is applicable to the given calendarfield
.For example, if this
Calendar
is aGregorianCalendar
and its date is 2005-01-01, then the string representation of theMONTH
field would be "January" in the long style in an English locale or "Jan" in the short style. However, no string representation would be available for theDAY_OF_MONTH
field, and this method would returnnull
.The default implementation supports the calendar fields for which a
DateFormatSymbols
has names in the givenlocale
.- Parameters:
field
- the calendar field for which the string representation is returnedstyle
- the style applied to the string representation; one ofSHORT
orLONG
.locale
- the locale for the string representation- Returns:
- the string representation of the given
field
in the givenstyle
, ornull
if no string representation is applicable. - Throws:
IllegalArgumentException
- iffield
orstyle
is invalid, or if thisCalendar
is non-lenient and any of the calendar fields have invalid valuesNullPointerException
- iflocale
is null- Since:
- 1.6
getDisplayNames
public Map<String,Integer> getDisplayNames(int field, int style, Locale locale)
- Returns a
Map
containing all names of the calendarfield
in the givenstyle
andlocale
and their corresponding field values. For example, if thisCalendar
is aGregorianCalendar
, the returned map would contain "Jan" toJANUARY
, "Feb" toFEBRUARY
, and so on, in the short style in an English locale.The values of other calendar fields may be taken into account to determine a set of display names. For example, if this
Calendar
is a lunisolar calendar system and the year value given by theYEAR
field has a leap month, this method would return month names containing the leap month name, and month names are mapped to their values specific for the year.The default implementation supports display names contained in a
DateFormatSymbols
. For example, iffield
isMONTH
andstyle
isALL_STYLES
, this method returns aMap
containing all strings returned byDateFormatSymbols.getShortMonths()
andDateFormatSymbols.getMonths()
.- Parameters:
field
- the calendar field for which the display names are returnedstyle
- the style applied to the display names; one ofSHORT
,LONG
, orALL_STYLES
.locale
- the locale for the display names- Returns:
- a
Map
containing all display names instyle
andlocale
and their field values, ornull
if no display names are defined forfield
- Throws:
IllegalArgumentException
- iffield
orstyle
is invalid, or if thisCalendar
is non-lenient and any of the calendar fields have invalid valuesNullPointerException
- iflocale
is null- Since:
- 1.6
complete
protected void complete()
- Fills in any unset fields in the calendar fields. First, the
computeTime()
method is called if the time value (millisecond offset from the Epoch) has not been calculated from calendar field values. Then, thecomputeFields()
method is called to calculate all calendar field values.
equals
public boolean equals(Object obj)
- Compares this
Calendar
to the specifiedObject
. The result istrue
if and only if the argument is aCalendar
object of the same calendar system that represents the same time value (millisecond offset from the Epoch) under the sameCalendar
parameters as this object.The
Calendar
parameters are the values represented by theisLenient
,getFirstDayOfWeek
,getMinimalDaysInFirstWeek
andgetTimeZone
methods. If there is any difference in those parameters between the twoCalendar
s, this method returnsfalse
.Use the
compareTo
method to compare only the time values.- Parameters:
obj
- the object to compare with.- Returns:
true
if this object is equal toobj
;false
otherwise.- See Also:
Object.hashCode()
,Hashtable
hashCode
public int hashCode()
- Returns a hash code for this calendar.
- Returns:
- a hash code value for this object.
- Since:
- 1.2
- See Also:
Object.equals(java.lang.Object)
,Hashtable
before
public boolean before(Object when)
- Returns whether this
Calendar
represents a time before the time represented by the specifiedObject
. This method is equivalent to:
if and only ifcompareTo(when) < 0
when
is aCalendar
instance. Otherwise, the method returnsfalse
.- Parameters:
when
- theObject
to be compared- Returns:
true
if the time of thisCalendar
is before the time represented bywhen
;false
otherwise.- See Also:
compareTo(Calendar)
after
public boolean after(Object when)
- Returns whether this
Calendar
represents a time after the time represented by the specifiedObject
. This method is equivalent to:
if and only ifcompareTo(when) > 0
when
is aCalendar
instance. Otherwise, the method returnsfalse
.- Parameters:
when
- theObject
to be compared- Returns:
true
if the time of thisCalendar
is after the time represented bywhen
;false
otherwise.- See Also:
compareTo(Calendar)
compareTo
public int compareTo(Calendar anotherCalendar)
- Compares the time values (millisecond offsets from the Epoch) represented by two
Calendar
objects.- Specified by:
compareTo
in interfaceComparable<Calendar>
- Parameters:
anotherCalendar
- theCalendar
to be compared.- Returns:
- the value
0
if the time represented by the argument is equal to the time represented by thisCalendar
; a value less than0
if the time of thisCalendar
is before the time represented by the argument; and a value greater than0
if the time of thisCalendar
is after the time represented by the argument. - Throws:
NullPointerException
- if the specifiedCalendar
isnull
.IllegalArgumentException
- if the time value of the specifiedCalendar
object can't be obtained due to any invalid calendar values.- Since:
- 1.5
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. For example, to subtract 5 days from
the current time of the calendar, you can achieve it by calling:
add(Calendar.DAY_OF_MONTH, -5)
.- Parameters:
field
- the calendar field.amount
- the amount of date or time to be added to the field.- See Also:
roll(int,int)
,set(int,int)
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 fields. For example, to roll the current
date up by one day, you can achieve it by calling:
roll(Calendar.DATE, true). When rolling on the year or Calendar.YEAR field, it will roll the year value in the range between 1 and the value returned by calling
getMaximum(Calendar.YEAR)
. When rolling on the month or Calendar.MONTH field, other fields like date might conflict and, need to be changed. For instance, rolling the month on the date 01/31/96 will result in 02/29/96. When rolling on the hour-in-day or Calendar.HOUR_OF_DAY field, it will roll the hour value in the range between 0 and 23, which is zero-based.- 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.- See Also:
add(int,int)
,set(int,int)
roll
public void roll(int field, int amount)
- Adds the specified (signed) amount to the specified calendar field
without changing larger fields. A negative amount means to roll
down.
NOTE: This default implementation on
Calendar
just repeatedly calls the version ofroll()
that rolls by one unit. This may not always do the right thing. For example, if theDAY_OF_MONTH
field is 31, rolling through February will leave it set to 28. TheGregorianCalendar
version of this function takes care of this problem. Other subclasses should also provide overrides of this function that do the right thing.- Parameters:
field
- the calendar field.amount
- the signed amount to add to the calendarfield
.- Since:
- 1.2
- See Also:
roll(int,boolean)
,add(int,int)
,set(int,int)
setTimeZone
public void setTimeZone(TimeZone value)
- Sets the time zone with the given time zone value.
- Parameters:
value
- the given time zone.
getTimeZone
public TimeZone getTimeZone()
- Gets the time zone.
- Returns:
- the time zone object associated with this calendar.
setLenient
public void setLenient(boolean lenient)
- Specifies whether or not date/time interpretation is to be lenient. With
lenient interpretation, a date such as "February 942, 1996" will be
treated as being equivalent to the 941st day after February 1, 1996.
With strict (non-lenient) interpretation, such dates will cause an exception to be
thrown. The default is lenient.
- Parameters:
lenient
-true
if the lenient mode is to be turned on;false
if it is to be turned off.- See Also:
isLenient()
,DateFormat.setLenient(boolean)
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.- See Also:
setLenient(boolean)
setFirstDayOfWeek
public void setFirstDayOfWeek(int value)
- Sets what the first day of the week is; e.g.,
SUNDAY
in the U.S.,MONDAY
in France.- Parameters:
value
- the given first day of the week.- See Also:
getFirstDayOfWeek()
,getMinimalDaysInFirstWeek()
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.
- See Also:
setFirstDayOfWeek(int)
,getMinimalDaysInFirstWeek()
setMinimalDaysInFirstWeek
public void setMinimalDaysInFirstWeek(int value)
- Sets what the minimal days required in the first week of the year are;
For example, if the first week is defined as one that contains the first
day of the first month of a year, call this method with value 1. If it
must be a full week, use value 7.
- Parameters:
value
- the given minimal days required in the first week of the year.- See Also:
getMinimalDaysInFirstWeek()
getMinimalDaysInFirstWeek
public int getMinimalDaysInFirstWeek()
- Gets what the minimal days required in the first week of the year are;
e.g., if the first week is defined as one that contains the first day
of the first month of a year, this method returns 1. If
the minimal days required must be a full week, this method
returns 7.
- Returns:
- the minimal days required in the first week of the year.
- See Also:
setMinimalDaysInFirstWeek(int)
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 theget
method for any possible time value. The minimum value depends on calendar system specific parameters of the instance.- Parameters:
field
- the calendar field.- Returns:
- the minimum value for the given calendar field.
- See Also:
getMaximum(int)
,getGreatestMinimum(int)
,getLeastMaximum(int)
,getActualMinimum(int)
,getActualMaximum(int)
getMaximum
public abstract int getMaximum(int field)
- Returns the maximum value for the given calendar field of this
Calendar
instance. The maximum value is defined as the largest value returned by theget
method for any possible time value. The maximum value depends on calendar system specific parameters of the instance.- Parameters:
field
- the calendar field.- Returns:
- the maximum value for the given calendar field.
- See Also:
getMinimum(int)
,getGreatestMinimum(int)
,getLeastMaximum(int)
,getActualMinimum(int)
,getActualMaximum(int)
getGreatestMinimum
public abstract int getGreatestMinimum(int field)
- Returns the highest minimum value for the given calendar field
of this
Calendar
instance. The highest minimum value is defined as the largest value returned bygetActualMinimum(int)
for any possible time value. The greatest minimum value depends on calendar system specific parameters of the instance.- Parameters:
field
- the calendar field.- Returns:
- the highest minimum value for the given calendar field.
- See Also:
getMinimum(int)
,getMaximum(int)
,getLeastMaximum(int)
,getActualMinimum(int)
,getActualMaximum(int)
getLeastMaximum
public abstract int getLeastMaximum(int field)
- Returns the lowest maximum value for the given calendar field
of this
Calendar
instance. The lowest maximum value is defined as the smallest value returned bygetActualMaximum(int)
for any possible time value. The least maximum value depends on calendar system specific parameters of the instance. For example, aCalendar
for the Gregorian calendar system returns 28 for theDAY_OF_MONTH
field, because the 28th is the last day of the shortest month of this calendar, February in a common year.- Parameters:
field
- the calendar field.- Returns:
- the lowest maximum value for the given calendar field.
- See Also:
getMinimum(int)
,getMaximum(int)
,getGreatestMinimum(int)
,getActualMinimum(int)
,getActualMaximum(int)
getActualMinimum
public int getActualMinimum(int field)
- Returns the minimum value that the specified calendar field
could have, given the time value of this
Calendar
.The default implementation of this method uses an iterative algorithm to determine the actual minimum value for the calendar field. Subclasses should, if possible, override this with a more efficient implementation - in many cases, they can simply return
getMinimum()
.- Parameters:
field
- the calendar field- Returns:
- the minimum of the given calendar field for the time
value of this
Calendar
- Since:
- 1.2
- See Also:
getMinimum(int)
,getMaximum(int)
,getGreatestMinimum(int)
,getLeastMaximum(int)
,getActualMaximum(int)
getActualMaximum
public int getActualMaximum(int field)
- Returns the maximum value that the specified calendar field
could have, given the time value of this
Calendar
. For example, the actual maximum value of theMONTH
field is 12 in some years, and 13 in other years in the Hebrew calendar system.The default implementation of this method uses an iterative algorithm to determine the actual maximum value for the calendar field. Subclasses should, if possible, override this with a more efficient implementation.
- Parameters:
field
- the calendar field- Returns:
- the maximum of the given calendar field for the time
value of this
Calendar
- Since:
- 1.2
- See Also:
getMinimum(int)
,getMaximum(int)
,getGreatestMinimum(int)
,getLeastMaximum(int)
,getActualMinimum(int)
clone
public Object clone()
- Creates and returns a copy of this object.
- Returns:
- a copy of this object.
- See Also:
Cloneable
toString
public String toString()
- Return a string representation of this calendar. This method
is intended to be used only for debugging purposes, and the
format of the returned string may vary between implementations.
The returned string may be empty but may not be
null
.- Returns:
- a string representation of this calendar.
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Java™ Platform Standard Ed. 6 |
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