Package org.joda.time.chrono

Class GJChronology

java.lang.Object

org.joda.time.Chronology

org.joda.time.chrono.BaseChronology

org.joda.time.chrono.AssembledChronology

org.joda.time.chrono.GJChronology

All Implemented Interfaces:

Serializable

public final class GJChronology
extends AssembledChronology

Implements the Gregorian/Julian calendar system which is the calendar system used in most of the world. Wherever possible, it is recommended to use the ISOChronology instead.

The Gregorian calendar replaced the Julian calendar, and the point in time when this chronology switches can be controlled using the second parameter of the getInstance method. By default this cutover is set to the date the Gregorian calendar was first instituted, October 15, 1582.

Before this date, this chronology uses the proleptic Julian calendar (proleptic means extending indefinitely). The Julian calendar has leap years every four years, whereas the Gregorian has special rules for 100 and 400 years. A meaningful result will thus be obtained for all input values. However before 8 CE, Julian leap years were irregular, and before 45 BCE there was no Julian calendar.

This chronology differs from GregorianCalendar in that years in BCE are returned correctly. Thus year 1 BCE is returned as -1 instead of 1. The yearOfEra field produces results compatible with GregorianCalendar.

The Julian calendar does not have a year zero, and so year -1 is followed by year 1. If the Gregorian cutover date is specified at or before year -1 (Julian), year zero is defined. In other words, the proleptic Gregorian chronology used by this class has a year zero.

To create a pure proleptic Julian chronology, use JulianChronology, and to create a pure proleptic Gregorian chronology, use GregorianChronology.

GJChronology is thread-safe and immutable.

Since:

1.0

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	GJChronology.CutoverField	This basic cutover field adjusts calls to 'get' and 'set' methods, and assumes that calls to add and addWrapField are unaffected by the cutover.
private final class	GJChronology.ImpreciseCutoverField	Cutover field for variable length fields.
private static class	GJChronology.LinkedDurationField	Links the duration back to a ImpreciseCutoverField.

Nested classes/interfaces inherited from class org.joda.time.chrono.AssembledChronology

AssembledChronology.Fields

Field Summary

Fields

Modifier and Type	Field	Description
private static final ConcurrentHashMap<GJCacheKey,GJChronology>	cCache	Cache of zone to chronology list
(package private) static final Instant	DEFAULT_CUTOVER	The default GregorianJulian cutover point.
private Instant	iCutoverInstant
private long	iCutoverMillis
private long	iGapDuration
private GregorianChronology	iGregorianChronology
private JulianChronology	iJulianChronology
private static final long	serialVersionUID	Serialization lock

Constructor Summary

Constructors

Modifier	Constructor	Description
private	GJChronology(JulianChronology julian, GregorianChronology gregorian, Instant cutoverInstant)
private	GJChronology(Chronology base, JulianChronology julian, GregorianChronology gregorian, Instant cutoverInstant)	Called when applying a time zone.

Method Summary

Modifier and Type	Method	Description
protected void	assemble(AssembledChronology.Fields fields)	Invoked by the constructor and after deserialization to allow subclasses to define all of its supported fields.
private static long	convertByWeekyear(long instant, Chronology from, Chronology to)	Convert a datetime from one chronology to another.
private static long	convertByYear(long instant, Chronology from, Chronology to)	Convert a datetime from one chronology to another.
boolean	equals(Object obj)	Checks if this chronology instance equals another.
long	getDateTimeMillis(int year, int monthOfYear, int dayOfMonth, int millisOfDay)	Returns a datetime millisecond instant, formed from the given year, month, day, and millisecond values.
long	getDateTimeMillis(int year, int monthOfYear, int dayOfMonth, int hourOfDay, int minuteOfHour, int secondOfMinute, int millisOfSecond)	Returns a datetime millisecond instant, formed from the given year, month, day, hour, minute, second, and millisecond values.
Instant	getGregorianCutover()	Gets the cutover instant between Gregorian and Julian chronologies.
static GJChronology	getInstance()	Factory method returns instances of the default GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone)	Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone, long gregorianCutover, int minDaysInFirstWeek)	Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone, ReadableInstant gregorianCutover)	Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone, ReadableInstant gregorianCutover, int minDaysInFirstWeek)	Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstanceUTC()	Factory method returns instances of the default GJ cutover chronology.
int	getMinimumDaysInFirstWeek()	Gets the minimum days needed for a week to be the first week in a year.
DateTimeZone	getZone()	Returns the DateTimeZone that this Chronology operates in, or null if unspecified.
(package private) long	gregorianToJulianByWeekyear(long instant)
(package private) long	gregorianToJulianByYear(long instant)
int	hashCode()	A suitable hash code for the chronology.
(package private) long	julianToGregorianByWeekyear(long instant)
(package private) long	julianToGregorianByYear(long instant)
private Object	readResolve()	Serialization singleton
String	toString()	Gets a debugging toString.
Chronology	withUTC()	Gets the Chronology in the UTC time zone.
Chronology	withZone(DateTimeZone zone)	Gets the Chronology in a specific time zone.

Methods inherited from class org.joda.time.chrono.AssembledChronology

centuries, centuryOfEra, clockhourOfDay, clockhourOfHalfday, dayOfMonth, dayOfWeek, dayOfYear, days, era, eras, getBase, getDateTimeMillis, getParam, halfdayOfDay, halfdays, hourOfDay, hourOfHalfday, hours, millis, millisOfDay, millisOfSecond, minuteOfDay, minuteOfHour, minutes, monthOfYear, months, secondOfDay, secondOfMinute, seconds, weekOfWeekyear, weeks, weekyear, weekyearOfCentury, weekyears, year, yearOfCentury, yearOfEra, years

Methods inherited from class org.joda.time.chrono.BaseChronology

add, add, get, get, get, set, validate

Methods inherited from class java.lang.Object

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

Field Details

serialVersionUID

private static final long serialVersionUID

Serialization lock

See Also:

• Constant Field Values

DEFAULT_CUTOVER

static final Instant DEFAULT_CUTOVER

The default GregorianJulian cutover point.

cCache

private static final ConcurrentHashMap<GJCacheKey,GJChronology> cCache

Cache of zone to chronology list

iJulianChronology

private JulianChronology iJulianChronology

iGregorianChronology

private GregorianChronology iGregorianChronology

iCutoverInstant

private Instant iCutoverInstant

iCutoverMillis

private long iCutoverMillis

iGapDuration

private long iGapDuration

Constructor Details

GJChronology

private GJChronology(JulianChronology julian,
 GregorianChronology gregorian,
 Instant cutoverInstant)

Parameters:

julian - chronology used before the cutover instant

gregorian - chronology used at and after the cutover instant

cutoverInstant - instant when the gregorian chronology began

GJChronology

private GJChronology(Chronology base,
 JulianChronology julian,
 GregorianChronology gregorian,
 Instant cutoverInstant)

Called when applying a time zone.

Method Details

convertByYear

private static long convertByYear(long instant,
 Chronology from,
 Chronology to)

Convert a datetime from one chronology to another.

convertByWeekyear

private static long convertByWeekyear(long instant,
 Chronology from,
 Chronology to)

Convert a datetime from one chronology to another.

getInstanceUTC

public static GJChronology getInstanceUTC()

Factory method returns instances of the default GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

The time zone of the returned instance is UTC.

Returns:

the chronology, not null

getInstance

public static GJChronology getInstance()

Factory method returns instances of the default GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

The returned chronology is in the default time zone.

Returns:

the chronology, not null

getInstance

public static GJChronology getInstance(DateTimeZone zone)

Factory method returns instances of the GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

Parameters:

zone - the time zone to use, null is default

Returns:

the chronology, not null

getInstance

public static GJChronology getInstance(DateTimeZone zone,
 ReadableInstant gregorianCutover)

Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

Parameters:

zone - the time zone to use, null is default

gregorianCutover - the cutover to use, null means default

Returns:

the chronology, not null

getInstance

public static GJChronology getInstance(DateTimeZone zone,
 ReadableInstant gregorianCutover,
 int minDaysInFirstWeek)

Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

Parameters:

zone - the time zone to use, null is default

gregorianCutover - the cutover to use, null means default

minDaysInFirstWeek - minimum number of days in first week of the year; default is 4

Returns:

the chronology, not null

getInstance

public static GJChronology getInstance(DateTimeZone zone,
 long gregorianCutover,
 int minDaysInFirstWeek)

Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

Parameters:

zone - the time zone to use, null is default

gregorianCutover - the cutover to use

minDaysInFirstWeek - minimum number of days in first week of the year; default is 4

Returns:

the chronology, not null

readResolve

private Object readResolve()

Serialization singleton

getZone

public DateTimeZone getZone()

Description copied from class: BaseChronology

Returns the DateTimeZone that this Chronology operates in, or null if unspecified.

Overrides:

getZone in class AssembledChronology

Returns:

DateTimeZone null if unspecified

withUTC

public Chronology withUTC()

Gets the Chronology in the UTC time zone.

Specified by:

withUTC in class BaseChronology

Returns:

the chronology in UTC

withZone

public Chronology withZone(DateTimeZone zone)

Gets the Chronology in a specific time zone.

Specified by:

withZone in class BaseChronology

Parameters:

zone - the zone to get the chronology in, null is default

Returns:

the chronology

See Also:

• ZonedChronology

getDateTimeMillis

public long getDateTimeMillis(int year,
 int monthOfYear,
 int dayOfMonth,
 int millisOfDay)
                       throws IllegalArgumentException

Description copied from class: BaseChronology

Returns a datetime millisecond instant, formed from the given year, month, day, and millisecond values. The set of given values must refer to a valid datetime, or else an IllegalArgumentException is thrown.

The default implementation calls upon separate DateTimeFields to determine the result. Subclasses are encouraged to provide a more efficient implementation.

Overrides:

getDateTimeMillis in class AssembledChronology

Parameters:

year - year to use

monthOfYear - month to use

dayOfMonth - day of month to use

millisOfDay - millisecond to use

Returns:

millisecond instant from 1970-01-01T00:00:00Z

Throws:

IllegalArgumentException - if the values are invalid

getDateTimeMillis

public long getDateTimeMillis(int year,
 int monthOfYear,
 int dayOfMonth,
 int hourOfDay,
 int minuteOfHour,
 int secondOfMinute,
 int millisOfSecond)
                       throws IllegalArgumentException

Description copied from class: BaseChronology

Returns a datetime millisecond instant, formed from the given year, month, day, hour, minute, second, and millisecond values. The set of given values must refer to a valid datetime, or else an IllegalArgumentException is thrown.

The default implementation calls upon separate DateTimeFields to determine the result. Subclasses are encouraged to provide a more efficient implementation.

Overrides:

getDateTimeMillis in class AssembledChronology

Parameters:

year - year to use

monthOfYear - month to use

dayOfMonth - day of month to use

hourOfDay - hour to use

minuteOfHour - minute to use

secondOfMinute - second to use

millisOfSecond - millisecond to use

Returns:

millisecond instant from 1970-01-01T00:00:00Z

Throws:

IllegalArgumentException - if the values are invalid

getGregorianCutover

public Instant getGregorianCutover()

Gets the cutover instant between Gregorian and Julian chronologies.

Returns:

the cutover instant

getMinimumDaysInFirstWeek

public int getMinimumDaysInFirstWeek()

Gets the minimum days needed for a week to be the first week in a year.

Returns:

the minimum days

equals

public boolean equals(Object obj)

Checks if this chronology instance equals another.

Overrides:

equals in class Object

Parameters:

obj - the object to compare to

Returns:

true if equal

Since:

1.6

hashCode

public int hashCode()

A suitable hash code for the chronology.

Overrides:

hashCode in class Object

Returns:

the hash code

Since:

1.6

toString

public String toString()

Gets a debugging toString.

Specified by:

toString in class BaseChronology

Returns:

a debugging string

assemble

protected void assemble(AssembledChronology.Fields fields)

Description copied from class: AssembledChronology

Invoked by the constructor and after deserialization to allow subclasses to define all of its supported fields. All unset fields default to unsupported instances.

Specified by:

assemble in class AssembledChronology

Parameters:

fields - container of fields

julianToGregorianByYear

long julianToGregorianByYear(long instant)

gregorianToJulianByYear

long gregorianToJulianByYear(long instant)

julianToGregorianByWeekyear

long julianToGregorianByWeekyear(long instant)

gregorianToJulianByWeekyear

long gregorianToJulianByWeekyear(long instant)