net.time4j.engine

Interface ChronoDisplay

All Known Implementing Classes:

Calendrical, ChronoEntity, Moment, PlainDate, PlainTime, PlainTimestamp, TimePoint, ZonalMoment

public interface ChronoDisplay

Represents a view on a set of chronological elements associated with their temporal values.

A ChronoDisplay serves mainly for formatted output.

Since:

2.0

Author:

Meno Hochschild

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contains(ChronoElement<?> element) Queries if the value for given chronological element can be accessed via get(element).
<V> V	get(ChronoElement<V> element) Returns the partial value associated with given chronological element.
<V> V	getMaximum(ChronoElement<V> element) Yields the maximum value of given chronological element in the current context of this object.
<V> V	getMinimum(ChronoElement<V> element) Yields the minimum value of given chronological element in the current context of this object.
TZID	getTimezone() Returns the associated timezone ID for display purposes if available.
boolean	hasTimezone() Queries if this object contains a timezone for display purposes.

Method Detail

contains

boolean contains(ChronoElement<?> element)

Queries if the value for given chronological element can be accessed via get(element).

If the argument is missing then this method will yield false. Note: Elements which are not registered but define a suitable rule are also accessible.

Parameters:

element - chronological element to be asked (optional)

Returns:

true if the method get(ChronoElement) can be called without exception else false

See Also:

get(ChronoElement)

get

<V> V get(ChronoElement<V> element)

Returns the partial value associated with given chronological element.

Type Parameters:

V - generic type of element value

Parameters:

element - element which has the value

Returns:

associated element value as object (never null)

Throws:

ChronoException - if the element is not registered and there is no element rule for evaluating the value

See Also:

contains(ChronoElement)

getMinimum

<V> V getMinimum(ChronoElement<V> element)

Yields the minimum value of given chronological element in the current context of this object.

The definition of a minimum and a maximum does generally not imply that every intermediate value between minimum and maximum is valid in this context. For example in the timezone Europe/Berlin the hour [T02:00] will be invalid if switching to summer time.

In most cases the minimum value is not dependent on this context.

Type Parameters:

V - generic type of element value

Parameters:

element - element whose minimum value is to be evaluated

Returns:

minimum maybe context-dependent element value

Throws:

ChronoException - if the element is not registered and there is no element rule for getting the minimum value

See Also:

ChronoElement.getDefaultMinimum(), getMaximum(ChronoElement)

getMaximum

<V> V getMaximum(ChronoElement<V> element)

Yields the maximum value of given chronological element in the current context of this object.

Maximum values are different from minimum case often dependent on the context. An example is the element SECOND_OF_MINUTE whose maximum is normally 59 but can differ in UTC-context with leap seconds. Another more common example is the maximum of the element DAY_OF_MONTH (28-31) which is dependent on the month and year of this context (leap years!).

Note: In timezone-related timestamps possible offset jumps inducing gaps on the local timeline will be conserved. That means that minimum and maximum do not guarantee a continuum of valid intermediate values.

Type Parameters:

V - generic type of element value

Parameters:

element - element whose maximum value is to be evaluated

Returns:

maximum maybe context-dependent element value

Throws:

ChronoException - if the element is not registered and there is no element rule for getting the maximum value

See Also:

ChronoElement.getDefaultMaximum(), getMinimum(ChronoElement)

hasTimezone

boolean hasTimezone()

Queries if this object contains a timezone for display purposes.

Returns:

true if a timezone is available and can be achieved with getTimezone() else false

getTimezone

TZID getTimezone()

Returns the associated timezone ID for display purposes if available.

Note: Although global types like Moment indeed have a timezone reference (namely UTC+00:00), such types will not support formatted output without explicitly giving a timezone for display purposes. Therefore calling this method on global types will throw an exception. This method is not just about any timezone reference but a timezone designed for display purposes.

Returns:

timezone identifier if available

Throws:

ChronoException - if the timezone is not available

See Also:

hasTimezone()