java.util.Calendar
java.util.GregorianCalendar
|
Build 1.1_r1 (from source) | |||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | |||||||||
java.lang.Object
public class GregorianCalendar
GregorianCalendar is a concrete subclass of Calendar
and provides the standard calendar used by most of the world.
The standard (Gregorian) calendar has 2 eras, BC and AD.
This implementation handles a single discontinuity, which corresponds by
default to the date the Gregorian calendar was instituted (October 15, 1582
in some countries, later in others). The cutover date may be changed by the
caller by calling setGregorianChange().
Historically, in those countries which adopted the Gregorian calendar first,
October 4, 1582 was thus followed by October 15, 1582. This calendar models
this correctly. Before the Gregorian cutover, GregorianCalendar
implements the Julian calendar. The only difference between the Gregorian and
the Julian calendar is the leap year rule. The Julian calendar specifies leap
years every four years, whereas the Gregorian calendar omits century years
which are not divisible by 400.
GregorianCalendar implements proleptic Gregorian
and Julian calendars. That is, dates are computed by extrapolating the
current rules indefinitely far backward and forward in time. As a result,
GregorianCalendar may be used for all years to generate
meaningful and consistent results. However, dates obtained using
GregorianCalendar are historically accurate only from March 1,
4 AD onward, when modern Julian calendar rules were adopted. Before this
date, leap year rules were applied irregularly, and before 45 BC the Julian
calendar did not even exist.
Prior to the institution of the Gregorian calendar, New Year's Day was March 25. To avoid confusion, this calendar always uses January 1. A manual adjustment may be made if desired for dates that are prior to the Gregorian changeover and which fall between January 1 and March 24.
Values calculated for the WEEK_OF_YEAR field range from 1 to
53. Week 1 for a year is the earliest seven day period starting on
getFirstDayOfWeek() that contains at least
getMinimalDaysInFirstWeek() days from that year. It thus
depends on the values of getMinimalDaysInFirstWeek(),
getFirstDayOfWeek(), and the day of the week of January 1.
Weeks between week 1 of one year and week 1 of the following year are
numbered sequentially from 2 to 52 or 53 (as needed).
For example, January 1, 1998 was a Thursday. If
getFirstDayOfWeek() is MONDAY and
getMinimalDaysInFirstWeek() is 4 (these are the values
reflecting ISO 8601 and many national standards), then week 1 of 1998 starts
on December 29, 1997, and ends on January 4, 1998. If, however,
getFirstDayOfWeek() is SUNDAY, then week 1 of
1998 starts on January 4, 1998, and ends on January 10, 1998; the first three
days of 1998 then are part of week 53 of 1997.
Values calculated for the WEEK_OF_MONTH field range from 0 or
1 to 4 or 5. Week 1 of a month (the days with WEEK_OF_MONTH =
1)
is the earliest set of at least getMinimalDaysInFirstWeek()
contiguous days in that month, ending on the day before
getFirstDayOfWeek(). Unlike week 1 of a year, week 1 of a
month may be shorter than 7 days, need not start on
getFirstDayOfWeek(), and will not include days of the
previous month. Days of a month before week 1 have a
WEEK_OF_MONTH of 0.
For example, if getFirstDayOfWeek() is SUNDAY
and getMinimalDaysInFirstWeek() is 4, then the first week of
January 1998 is Sunday, January 4 through Saturday, January 10. These days
have a WEEK_OF_MONTH of 1. Thursday, January 1 through
Saturday, January 3 have a WEEK_OF_MONTH of 0. If
getMinimalDaysInFirstWeek() is changed to 3, then January 1
through January 3 have a WEEK_OF_MONTH of 1.
Example:
// get the supported ids for GMT-08:00 (Pacific Standard Time)
String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000);
// if no ids were returned, something is wrong. get out.
if (ids.length == 0)
System.exit(0);
// begin output
System.out.println("Current Time");
// create a Pacific Standard Time time zone
SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]);
// set up rules for daylight savings time
pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
// create a GregorianCalendar with the Pacific Daylight time zone
// and the current date and time
Calendar calendar = new GregorianCalendar(pdt);
Date trialTime = new Date();
calendar.setTime(trialTime);
// print out a bunch of interesting things
System.out.println("ERA: " + calendar.get(Calendar.ERA));
System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
System.out.println("DATE: " + calendar.get(Calendar.DATE));
System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
System.out.println("DAY_OF_WEEK_IN_MONTH: "
+ calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
System.out.println("ZONE_OFFSET: "
+ (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000)));
System.out.println("DST_OFFSET: "
+ (calendar.get(Calendar.DST_OFFSET)/(60*60*1000)));
System.out.println("Current Time, with hour reset to 3");
calendar.clear(Calendar.HOUR_OF_DAY); // so doesn't override
calendar.set(Calendar.HOUR, 3);
System.out.println("ERA: " + calendar.get(Calendar.ERA));
System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
System.out.println("DATE: " + calendar.get(Calendar.DATE));
System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
System.out.println("DAY_OF_WEEK_IN_MONTH: "
+ calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
System.out.println("ZONE_OFFSET: "
+ (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours
System.out.println("DST_OFFSET: "
+ (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours
Calendar,
TimeZone,
Serialized Form| Field Summary | |
|---|---|
static int |
AD
Value for the AD era. |
static int |
BC
Value for the BC era. |
(package private) static byte[] |
DaysInMonth
|
| Fields inherited from class java.util.Calendar |
|---|
AM, AM_PM, APRIL, areFieldsSet, AUGUST, DATE, DAY_OF_MONTH, DAY_OF_WEEK, DAY_OF_WEEK_IN_MONTH, DAY_OF_YEAR, DECEMBER, DST_OFFSET, ERA, FEBRUARY, FIELD_COUNT, fields, FRIDAY, HOUR, HOUR_OF_DAY, isSet, isTimeSet, JANUARY, JULY, JUNE, lastDateFieldSet, lastTimeFieldSet, MARCH, MAY, MILLISECOND, MINUTE, MONDAY, MONTH, NOVEMBER, OCTOBER, PM, SATURDAY, SECOND, SEPTEMBER, SUNDAY, THURSDAY, time, TUESDAY, UNDECIMBER, WEDNESDAY, WEEK_OF_MONTH, WEEK_OF_YEAR, YEAR, ZONE_OFFSET |
| Constructor Summary | |
|---|---|
GregorianCalendar()
Constructs a new GregorianCalendar initialized to the current date and
time with the default Locale and TimeZone. |
|
GregorianCalendar(boolean ignored)
|
|
GregorianCalendar(int year,
int month,
int day)
Constructs a new GregorianCalendar initialized to midnight in the default
TimeZone and Locale on the specified date. |
|
GregorianCalendar(int year,
int month,
int day,
int hour,
int minute)
Constructs a new GregorianCalendar initialized to the specified date and
time in the default TimeZone and Locale. |
|
GregorianCalendar(int year,
int month,
int day,
int hour,
int minute,
int second)
Constructs a new GregorianCalendar initialized to the specified date and
time in the default TimeZone and Locale. |
|
GregorianCalendar(Locale locale)
Constructs a new GregorianCalendar initialized to the current date and
time and using the specified Locale and the default TimeZone. |
|
GregorianCalendar(long milliseconds)
|
|
GregorianCalendar(TimeZone timezone)
Constructs a new GregorianCalendar initialized to the current date and
time and using the specified TimeZone and the default Locale. |
|
GregorianCalendar(TimeZone timezone,
Locale locale)
Constructs a new GregorianCalendar initialized to the current date and
time and using the specified TimeZone and Locale. |
|
| Method Summary | |
|---|---|
void |
add(int field,
int value)
Adds the specified amount to a Calendar field. |
Object |
clone()
Creates new instance of GregorianCalendar with the same properties. |
protected void |
computeFields()
Computes the Calendar fields from time. |
protected void |
computeTime()
Computes time from the Calendar fields. |
boolean |
equals(Object object)
Compares the specified Object to this GregorianCalendar and returns whether
they are equal. |
int |
getActualMaximum(int field)
Gets the maximum value of the specified field for the current date. |
int |
getActualMinimum(int field)
Gets the minimum value of the specified field for the current date. |
int |
getGreatestMinimum(int field)
Gets the greatest minimum value of the specified field. |
Date |
getGregorianChange()
Returns the gregorian change date of this calendar. |
int |
getLeastMaximum(int field)
Gets the smallest maximum value of the specified field. |
int |
getMaximum(int field)
Gets the greatest maximum value of the specified field. |
int |
getMinimum(int field)
Gets the smallest minimum value of the specified field. |
(package private) int |
getOffset(long localTime)
|
int |
hashCode()
Returns an integer hash code for the receiver. |
boolean |
isLeapYear(int year)
Returns whether the specified year is a leap year. |
void |
roll(int field,
boolean increment)
Increments or decrements the specified field and wraps the value of the field when it goes beyond the maximum or minimum value for the current date. |
void |
roll(int field,
int value)
Adds the specified amount the specified field and wraps the value of the field when it goes beyond the maximum or minimum value for the current date. |
void |
setFirstDayOfWeek(int value)
Sets the first day of the week for this Calendar. |
void |
setGregorianChange(Date date)
Sets the gregorian change date of this calendar. |
void |
setMinimalDaysInFirstWeek(int value)
Sets the minimal days in the first week of the year. |
| Methods inherited from class java.util.Calendar |
|---|
after, before, clear, clear, compareTo, complete, get, getAvailableLocales, getFirstDayOfWeek, getInstance, getInstance, getInstance, getInstance, getMinimalDaysInFirstWeek, getTime, getTimeInMillis, getTimeZone, internalGet, isLenient, isSet, set, set, set, set, setLenient, setTime, setTimeInMillis, setTimeZone, toString |
| Methods inherited from class java.lang.Object |
|---|
finalize, getClass, notify, notifyAll, wait, wait, wait |
| Field Detail |
|---|
public static final int BC
public static final int AD
static byte[] DaysInMonth
| Constructor Detail |
|---|
public GregorianCalendar()
GregorianCalendar initialized to the current date and
time with the default Locale and TimeZone.
public GregorianCalendar(int year,
int month,
int day)
GregorianCalendar initialized to midnight in the default
TimeZone and Locale on the specified date.
year - the year.month - the month.day - the day of the month.
public GregorianCalendar(int year,
int month,
int day,
int hour,
int minute)
GregorianCalendar initialized to the specified date and
time in the default TimeZone and Locale.
year - the year.month - the month.day - the day of the month.hour - the hour.minute - the minute.
public GregorianCalendar(int year,
int month,
int day,
int hour,
int minute,
int second)
GregorianCalendar initialized to the specified date and
time in the default TimeZone and Locale.
year - the year.month - the month.day - the day of the month.hour - the hour.minute - the minute.second - the second.GregorianCalendar(long milliseconds)
public GregorianCalendar(Locale locale)
GregorianCalendar initialized to the current date and
time and using the specified Locale and the default TimeZone.
locale - the Locale.public GregorianCalendar(TimeZone timezone)
GregorianCalendar initialized to the current date and
time and using the specified TimeZone and the default Locale.
timezone - the TimeZone.
public GregorianCalendar(TimeZone timezone,
Locale locale)
GregorianCalendar initialized to the current date and
time and using the specified TimeZone and Locale.
timezone - the TimeZone.locale - the Locale.GregorianCalendar(boolean ignored)
| Method Detail |
|---|
public void add(int field,
int value)
Calendar field.
add in class Calendarfield - the Calendar field to modify.value - the amount to add to the field.
IllegalArgumentException - when the specified field is DST_OFFSET or ZONE_OFFSET.public Object clone()
GregorianCalendar with the same properties.
clone in class CalendarGregorianCalendar.Cloneableprotected void computeFields()
CalendarCalendar fields from time.
computeFields in class Calendarprotected void computeTime()
Calendartime from the Calendar fields.
computeTime in class Calendarpublic boolean equals(Object object)
Object to this GregorianCalendar and returns whether
they are equal. To be equal, the Object must be an instance of GregorianCalendar and
have the same properties.
equals in class Calendarobject - the Object to compare with this GregorianCalendar.
true if object is equal to this
GregorianCalendar, false otherwise.
IllegalArgumentException - when the time is not set and the time cannot be computed
from the current field values.hashCode()public int getActualMaximum(int field)
getActualMaximum in class Calendarfield - the field.
public int getActualMinimum(int field)
getMinimum().
getActualMinimum in class Calendarfield - the field.
public int getGreatestMinimum(int field)
getMinimum().
getGreatestMinimum in class Calendarfield - the field.
public final Date getGregorianChange()
Date which represents the gregorian change date.public int getLeastMaximum(int field)
getLeastMaximum in class Calendarfield - the field.
public int getMaximum(int field)
getMaximum in class Calendarfield - the field.
public int getMinimum(int field)
getMinimum in class Calendarfield - the field.
int getOffset(long localTime)
public int hashCode()
hashCode in class Calendarequals(java.lang.Object)public boolean isLeapYear(int year)
year - the year.
true if the specified year is a leap year, false
otherwise.
public void roll(int field,
int value)
roll in class Calendarfield - the field to roll.value - the amount to add.
IllegalArgumentException - when an invalid field is specified.
public void roll(int field,
boolean increment)
roll in class Calendarfield - the field to roll.increment - true to increment the field, false to
decrement.
IllegalArgumentException - when an invalid field is specified.public void setGregorianChange(Date date)
date - a Date which represents the gregorian change date.public void setFirstDayOfWeek(int value)
CalendarCalendar.
setFirstDayOfWeek in class Calendarvalue - a Calendar day of the week.public void setMinimalDaysInFirstWeek(int value)
Calendar
setMinimalDaysInFirstWeek in class Calendarvalue - the minimal days in the first week of the year.
|
Build 1.1_r1 (from source) | |||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | |||||||||