- java.lang.Object
-
- java.util.Calendar
-
- All Implemented Interfaces:
- Serializable, Cloneable, Comparable<Calendar>
- Direct Known Subclasses:
- GregorianCalendar
public abstract class Calendar extends Object implements Serializable, Cloneable, Comparable<Calendar>
TheCalendar
class is an abstract class that provides methods for converting between a specific instant in time and a set ofcalendar fields
such asYEAR
,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
'sgetInstance
method returns aCalendar
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 valueMONTH == JANUARY
for all calendars. Other values are defined by the concrete subclass, such asERA
. 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 aCalendar
will not be interpreted until it needs to calculate its time value (milliseconds from the Epoch) or values of the calendar fields. Calling theget
,getTimeInMillis
,getTime
,add
androll
involves such calculation.Leniency
Calendar
has two modes for interpreting the calendar fields, lenient and non-lenient. When aCalendar
is in lenient mode, it accepts a wider range of calendar field values than it produces. When aCalendar
recomputes calendar field values for return byget()
, all of the calendar fields are normalized. For example, a lenientGregorianCalendar
interpretsMONTH == 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, aGregorianCalendar
always producesDAY_OF_MONTH
values between 1 and the length of the month. A non-lenientGregorianCalendar
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 aCalendar
is constructed. They may also be specified explicitly through the methods for setting their values.When setting or getting the
WEEK_OF_MONTH
orWEEK_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 ongetFirstDayOfWeek()
and containing at leastgetMinimalDaysInFirstWeek()
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 byget()
may be different. For example, a specificCalendar
subclass may designate the week before week 1 of a year as weekn
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.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, inGregorianCalendar
, 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()
, androll()
.set(f, value)
changes calendar fieldf
tovalue
. In addition, it sets an internal member variable to indicate that calendar fieldf
has been changed. Although calendar fieldf
is changed immediately, the calendar's time value in milliseconds is not recomputed until the next call toget()
,getTime()
,getTimeInMillis()
,add()
, orroll()
is made. Thus, multiple calls toset()
do not trigger multiple, unnecessary computations. As a result of changing a calendar field usingset()
, 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 returnvalue
set by the call to theset
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. Callingset(Calendar.MONTH, Calendar.SEPTEMBER)
sets the date to September 31, 1999. This is a temporary internal representation that resolves to October 1, 1999 ifgetTime()
is then called. However, a call toset(Calendar.DAY_OF_MONTH, 30)
before the call togetTime()
sets the date to September 30, 1999, since no recomputation occurs afterset()
itself.add(f, delta)
addsdelta
to fieldf
. This is equivalent to callingset(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. Callingadd(Calendar.MONTH, 13)
sets the calendar to September 30, 2000. Add rule 1 sets theMONTH
field to September, since adding 13 months to August gives September of the next year. SinceDAY_OF_MONTH
cannot be 31 in September in aGregorianCalendar
, add rule 2 sets theDAY_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 aGregorianCalendar
.roll(f, delta)
addsdelta
to fieldf
without changing larger fields. This is equivalent to callingadd(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()
androll()
, consider a user interface component with increment and decrement buttons for the month, day, and year, and an underlyingGregorianCalendar
. If the interface reads January 31, 1999 and the user presses the month increment button, what should it read? If the underlying implementation usesset()
, 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 eitheradd()
orroll()
, 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
Fields Modifier and Type Field and Description static int
ALL_STYLES
A style specifier forgetDisplayNames
indicating names in all styles, such as "January" and "Jan".static int
AM
Value of theAM_PM
field indicating the period of the day from midnight to just before noon.static int
AM_PM
Field number forget
andset
indicating whether theHOUR
is before or after noon.static int
APRIL
Value of theMONTH
field indicating the fourth month of the year in the Gregorian and Julian calendars.protected boolean
areFieldsSet
True iffields[]
are in sync with the currently set time.static int
AUGUST
Value of theMONTH
field indicating the eighth month of the year in the Gregorian and Julian calendars.static int
DATE
Field number forget
andset
indicating the day of the month.static int
DAY_OF_MONTH
Field number forget
andset
indicating the day of the month.static int
DAY_OF_WEEK
Field number forget
andset
indicating the day of the week.static int
DAY_OF_WEEK_IN_MONTH
Field number forget
andset
indicating the ordinal number of the day of the week within the current month.static int
DAY_OF_YEAR
Field number forget
andset
indicating the day number within the current year.static int
DECEMBER
Value of theMONTH
field indicating the twelfth month of the year in the Gregorian and Julian calendars.static int
DST_OFFSET
Field number forget
andset
indicating the daylight saving offset in milliseconds.static int
ERA
Field number forget
andset
indicating the era, e.g., AD or BC in the Julian calendar.static int
FEBRUARY
Value of theMONTH
field indicating the second month of the year in the Gregorian and Julian calendars.static int
FIELD_COUNT
The number of distinct fields recognized byget
andset
.protected int[]
fields
The calendar field values for the currently set time for this calendar.static int
FRIDAY
Value of theDAY_OF_WEEK
field indicating Friday.static int
HOUR
Field number forget
andset
indicating the hour of the morning or afternoon.static int
HOUR_OF_DAY
Field number forget
andset
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 oftime
is valid.static int
JANUARY
Value of theMONTH
field indicating the first month of the year in the Gregorian and Julian calendars.static int
JULY
Value of theMONTH
field indicating the seventh month of the year in the Gregorian and Julian calendars.static int
JUNE
Value of theMONTH
field indicating the sixth month of the year in the Gregorian and Julian calendars.static int
LONG
A style specifier forgetDisplayName
andgetDisplayNames
indicating a long name, such as "January".static int
MARCH
Value of theMONTH
field indicating the third month of the year in the Gregorian and Julian calendars.static int
MAY
Value of theMONTH
field indicating the fifth month of the year in the Gregorian and Julian calendars.static int
MILLISECOND
Field number forget
andset
indicating the millisecond within the second.static int
MINUTE
Field number forget
andset
indicating the minute within the hour.static int
MONDAY
Value of theDAY_OF_WEEK
field indicating Monday.static int
MONTH
Field number forget
andset
indicating the month.static int
NOVEMBER
Value of theMONTH
field indicating the eleventh month of the year in the Gregorian and Julian calendars.static int
OCTOBER
Value of theMONTH
field indicating the tenth month of the year in the Gregorian and Julian calendars.static int
PM
Value of theAM_PM
field indicating the period of the day from noon to just before midnight.static int
SATURDAY
Value of theDAY_OF_WEEK
field indicating Saturday.static int
SECOND
Field number forget
andset
indicating the second within the minute.static int
SEPTEMBER
Value of theMONTH
field indicating the ninth month of the year in the Gregorian and Julian calendars.static int
SHORT
A style specifier forgetDisplayName
andgetDisplayNames
indicating a short name, such as "Jan".static int
SUNDAY
Value of theDAY_OF_WEEK
field indicating Sunday.static int
THURSDAY
Value of theDAY_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 theDAY_OF_WEEK
field indicating Tuesday.static int
UNDECIMBER
Value of theMONTH
field indicating the thirteenth month of the year.static int
WEDNESDAY
Value of theDAY_OF_WEEK
field indicating Wednesday.static int
WEEK_OF_MONTH
Field number forget
andset
indicating the week number within the current month.static int
WEEK_OF_YEAR
Field number forget
andset
indicating the week number within the current year.static int
YEAR
Field number forget
andset
indicating the year.static int
ZONE_OFFSET
Field number forget
andset
indicating the raw offset from GMT in milliseconds.
-
Constructor Summary
Constructors Modifier Constructor and Description 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
Methods 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.boolean
after(Object when)
Returns whether thisCalendar
represents a time after the time represented by the specifiedObject
.boolean
before(Object when)
Returns whether thisCalendar
represents a time before the time represented by the specifiedObject
.void
clear()
Sets all the calendar field values and the time value (millisecond offset from the Epoch) of thisCalendar
undefined.void
clear(int field)
Sets the given calendar field value and the time value (millisecond offset from the Epoch) of thisCalendar
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 twoCalendar
objects.protected void
complete()
Fills in any unset fields in the calendar fields.protected abstract void
computeFields()
protected abstract void
computeTime()
boolean
equals(Object obj)
Compares thisCalendar
to the specifiedObject
.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 thisCalendar
.int
getActualMinimum(int field)
Returns the minimum value that the specified calendar field could have, given the time value of thisCalendar
.static Locale[]
getAvailableLocales()
Returns an array of all locales for which thegetInstance
methods of this class can return localized instances.String
getDisplayName(int field, int style, Locale locale)
Returns the string representation of the calendarfield
value in the givenstyle
andlocale
.Map<String,Integer>
getDisplayNames(int field, int style, Locale locale)
Returns aMap
containing all names of the calendarfield
in the givenstyle
andlocale
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 thisCalendar
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 thisCalendar
instance.abstract int
getMaximum(int field)
Returns the maximum value for the given calendar field of thisCalendar
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 thisCalendar
instance.Date
getTime()
long
getTimeInMillis()
Returns this Calendar's time value in milliseconds.TimeZone
getTimeZone()
Gets the time zone.int
getWeeksInWeekYear()
Returns the number of weeks in the week year represented by thisCalendar
.int
getWeekYear()
Returns the week year represented by thisCalendar
.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 aget
method call.boolean
isWeekDateSupported()
Returns whether thisCalendar
supports week dates.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 fieldsYEAR
,MONTH
, andDAY_OF_MONTH
.void
set(int year, int month, int date, int hourOfDay, int minute)
Sets the values for the calendar fieldsYEAR
,MONTH
,DAY_OF_MONTH
,HOUR_OF_DAY
, andMINUTE
.void
set(int year, int month, int date, int hourOfDay, int minute, int second)
Sets the values for the fieldsYEAR
,MONTH
,DAY_OF_MONTH
,HOUR
,MINUTE
, andSECOND
.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 givenDate
.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.void
setWeekDate(int weekYear, int weekOfYear, int dayOfWeek)
Sets the date of thisCalendar
with the the given date specifiers - week year, week of year, and day of week.String
toString()
Return a string representation of this calendar.
-
-
-
Field Detail
-
ERA
public static final int ERA
Field number forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
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 forget
andset
indicating the daylight saving 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 byget
andset
. Field numbers range from0..FIELD_COUNT-1
.- See Also:
- Constant Field Values
-
SUNDAY
public static final int SUNDAY
Value of theDAY_OF_WEEK
field indicating Sunday.- See Also:
- Constant Field Values
-
MONDAY
public static final int MONDAY
Value of theDAY_OF_WEEK
field indicating Monday.- See Also:
- Constant Field Values
-
TUESDAY
public static final int TUESDAY
Value of theDAY_OF_WEEK
field indicating Tuesday.- See Also:
- Constant Field Values
-
WEDNESDAY
public static final int WEDNESDAY
Value of theDAY_OF_WEEK
field indicating Wednesday.- See Also:
- Constant Field Values
-
THURSDAY
public static final int THURSDAY
Value of theDAY_OF_WEEK
field indicating Thursday.- See Also:
- Constant Field Values
-
FRIDAY
public static final int FRIDAY
Value of theDAY_OF_WEEK
field indicating Friday.- See Also:
- Constant Field Values
-
SATURDAY
public static final int SATURDAY
Value of theDAY_OF_WEEK
field indicating Saturday.- See Also:
- Constant Field Values
-
JANUARY
public static final int JANUARY
Value of theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theMONTH
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 theAM_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 theAM_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 forgetDisplayNames
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 forgetDisplayName
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 forgetDisplayName
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 ofFIELD_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 ofFIELD_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 oftime
is valid. The time is made invalid by a change to an item offield[]
.- See Also:
time
-
areFieldsSet
protected boolean areFieldsSet
True iffields[]
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()
-
-
Method Detail
-
getInstance
public static Calendar getInstance()
Gets a calendar using the default time zone and locale. TheCalendar
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. TheCalendar
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. TheCalendar
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. TheCalendar
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 thegetInstance
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()
- See Also:
complete()
,computeFields()
-
computeFields
protected abstract void computeFields()
Converts the current millisecond time valuetime
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
representing the time value. - See Also:
setTime(Date)
,getTimeInMillis()
-
setTime
public final void setTime(Date date)
Sets this Calendar's time with the givenDate
.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 thecomplete()
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 fieldsYEAR
,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 fieldsYEAR
,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 fieldsYEAR
,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 thisCalendar
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 thisCalendar
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 aget
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 calendarfield
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 aMap
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, thecomputeTime()
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 thisCalendar
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.- Overrides:
equals
in classObject
- Parameters:
obj
- the object to compare with.- Returns:
true
if this object is equal toobj
;false
otherwise.- See Also:
Object.hashCode()
,HashMap
-
hashCode
public int hashCode()
Returns a hash code for this calendar.- Overrides:
hashCode
in classObject
- Returns:
- a hash code value for this object.
- Since:
- 1.2
- See Also:
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
-
before
public boolean before(Object when)
Returns whether thisCalendar
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 thisCalendar
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 twoCalendar
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)
-
isWeekDateSupported
public boolean isWeekDateSupported()
Returns whether thisCalendar
supports week dates.The default implementation of this method returns
false
.- Returns:
true
if thisCalendar
supports week dates;false
otherwise.- Since:
- 1.7
- See Also:
getWeekYear()
,setWeekDate(int,int,int)
,getWeeksInWeekYear()
-
getWeekYear
public int getWeekYear()
Returns the week year represented by thisCalendar
. The week year is in sync with the week cycle. The first day of the first week is the first day of the week year.The default implementation of this method throws an
UnsupportedOperationException
.- Returns:
- the week year of this
Calendar
- Throws:
UnsupportedOperationException
- if any week year numbering isn't supported in thisCalendar
.- Since:
- 1.7
- See Also:
isWeekDateSupported()
,getFirstDayOfWeek()
,getMinimalDaysInFirstWeek()
-
setWeekDate
public void setWeekDate(int weekYear, int weekOfYear, int dayOfWeek)
Sets the date of thisCalendar
with the the given date specifiers - week year, week of year, and day of week.Unlike the
set
method, all of the calendar fields andtime
values are calculated upon return.If
weekOfYear
is out of the valid week-of-year range inweekYear
, theweekYear
andweekOfYear
values are adjusted in lenient mode, or anIllegalArgumentException
is thrown in non-lenient mode.The default implementation of this method throws an
UnsupportedOperationException
.- Parameters:
weekYear
- the week yearweekOfYear
- the week number based onweekYear
dayOfWeek
- the day of week value: one of the constants for theDAY_OF_WEEK
field:SUNDAY
, ...,SATURDAY
.- Throws:
IllegalArgumentException
- if any of the given date specifiers is invalid or any of the calendar fields are inconsistent with the given date specifiers in non-lenient modeUnsupportedOperationException
- if any week year numbering isn't supported in thisCalendar
.- Since:
- 1.7
- See Also:
isWeekDateSupported()
,getFirstDayOfWeek()
,getMinimalDaysInFirstWeek()
-
getWeeksInWeekYear
public int getWeeksInWeekYear()
Returns the number of weeks in the week year represented by thisCalendar
.The default implementation of this method throws an
UnsupportedOperationException
.- Returns:
- the number of weeks in the week year.
- Throws:
UnsupportedOperationException
- if any week year numbering isn't supported in thisCalendar
.- Since:
- 1.7
- See Also:
WEEK_OF_YEAR
,isWeekDateSupported()
,getWeekYear()
,getActualMaximum(int)
-
getMinimum
public abstract int getMinimum(int field)
Returns the minimum value for the given calendar field of thisCalendar
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 thisCalendar
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 thisCalendar
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 thisCalendar
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 thisCalendar
.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 thisCalendar
. 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)
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clone
public Object clone()
Creates and returns a copy of this object.
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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 benull
.
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