net.time4j.engine

Class Chronology<T extends ChronoEntity<T>>

java.lang.Object

net.time4j.engine.Chronology<T>

Type Parameters:

T - generic type compatible to ChronoEntity

All Implemented Interfaces:

ChronoMerger<T>

Direct Known Subclasses:

TimeAxis

public class Chronology<T extends ChronoEntity<T>>
extends Object
implements ChronoMerger<T>

Represents a system of chronological elements which form any kind of temporal value.

Author:

Meno Hochschild

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Chronology.Builder<T extends ChronoEntity<T>> Builder for creating a new chronology without any time axis.

Method Summary

Methods

Modifier and Type	Method and Description
T	createFrom(ChronoEntity<?> entity, AttributeQuery attributes, boolean preparsing) Creates a new entity of type T based on given chronological data.
T	createFrom(TimeSource<?> clock, AttributeQuery attributes) Creates a new entity which reflects current time.
CalendarSystem<T>	getCalendarSystem() Returns the associated calendar system if available.
Class<T>	getChronoType() Returns the chronological type.
List<ChronoExtension>	getExtensions() Returns all registered chronological extensions.
Set<ChronoElement<?>>	getRegisteredElements() Returns all registered chronological elements.
boolean	hasCalendarSystem() Queries if this chronology has a calendar system.
boolean	isRegistered(ChronoElement<?> element) Queries if given chronological element is registered together with its element rule.
boolean	isSupported(ChronoElement<?> element) Queries if given chronological element is supported by this chronology.
static <T extends ChronoEntity<T>> Chronology<T>	lookup(Class<T> chronoType) Returns a typed singleton per ChronoEntity-class.
ChronoDisplay	preformat(T context, AttributeQuery attributes) Transforms the current context/entity into another set of chronological values which finally shall be formatted using given attributes.
Chronology<?>	preparser() This method defines a child chronology which can preparse a chronological text.

Methods inherited from class java.lang.Object

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

Method Detail

getChronoType

public Class<T> getChronoType()

Returns the chronological type.

Returns:

type of time context

getRegisteredElements

public Set<ChronoElement<?>> getRegisteredElements()

Returns all registered chronological elements.

Returns:

unmodifiable set of elements without duplicates

isRegistered

public boolean isRegistered(ChronoElement<?> element)

Queries if given chronological element is registered together with its element rule.

Parameters:

element - element to be asked (optional)

Returns:

true if registered else false

isSupported

public boolean isSupported(ChronoElement<?> element)

Queries if given chronological element is supported by this chronology.

The element will be supported if it is either registered or defines a suitable element rule for this chronology.

Parameters:

element - element to be asked (optional)

Returns:

true if supported else false

createFrom

public T createFrom(TimeSource<?> clock,
           AttributeQuery attributes)

Description copied from interface: ChronoMerger

Creates a new entity which reflects current time.

In a date-only chronology this method will create the current date using the necessary timezone contained in given attributes.

Specified by:

createFrom in interface ChronoMerger<T extends ChronoEntity<T>>

Parameters:

clock - source for current time

attributes - configuration attributes which might contain the timezone to translate current time to local time

Returns:

new time context or null if given data are insufficient

createFrom

public T createFrom(ChronoEntity<?> entity,
           AttributeQuery attributes,
           boolean preparsing)

Description copied from interface: ChronoMerger

Creates a new entity of type T based on given chronological data.

Typically the method will query the given entity with different priorities for elements which can compose a new chronological entity (per group). For example a calendar date can be composed either by epoch days or the group (year)-(month)-(day-of-month) or the group (year)-(day-of-year) etc.

A text parser will call this method after having resolved a text into single chronological elements and values. Implementations should always validate the parsed values. In case of error, they are free to either throw an IllegalArgumentException or to generate and to save an error message by mean of the expression entity.with(ValidationElement.ERROR_MESSAGE, message.

Specified by:

createFrom in interface ChronoMerger<T extends ChronoEntity<T>>

Parameters:

entity - any chronological entity like parsed elements with their values

attributes - configuration attributes given by parser

preparsing - preparsing phase active?

Returns:

new time context or null if given data are insufficient

See Also:

ValidationElement.ERROR_MESSAGE

preformat

public ChronoDisplay preformat(T context,
                      AttributeQuery attributes)

Description copied from interface: ChronoMerger

Transforms the current context/entity into another set of chronological values which finally shall be formatted using given attributes.

Specified by:

preformat in interface ChronoMerger<T extends ChronoEntity<T>>

attributes - controls attributes during formatting

Returns:

replacement entity which will finally be used for formatting

preparser

public Chronology<?> preparser()

Description copied from interface: ChronoMerger

This method defines a child chronology which can preparse a chronological text.

Specified by:

preparser in interface ChronoMerger<T extends ChronoEntity<T>>

Returns:

preparsing chronology or null

getExtensions

public List<ChronoExtension> getExtensions()

Returns all registered chronological extensions.

This method will be called by format-API in order to collect all extension elements which are relevant for formatting.

Returns:

unmodifiable list of extensions

hasCalendarSystem

public boolean hasCalendarSystem()

Queries if this chronology has a calendar system.

Returns:

true if this chronology has a calendar system else false

See Also:

getCalendarSystem()

getCalendarSystem

public CalendarSystem<T> getCalendarSystem()

Returns the associated calendar system if available.

Returns:

calendar system, not null

Throws:

ChronoException - if the calendar system is unavailable

See Also:

hasCalendarSystem()

lookup

public static <T extends ChronoEntity<T>> Chronology<T> lookup(Class<T> chronoType)

Returns a typed singleton per ChronoEntity-class.

Type Parameters:

T - generic type of time context

Parameters:

chronoType - chronological type

Returns:

chronology or null if not found