Module org.elasticsearch.server

Package org.elasticsearch.cluster.metadata

Class ResettableValue<T>

java.lang.Object

org.elasticsearch.cluster.metadata.ResettableValue<T>

Type Parameters:

T -

public class ResettableValue<T>
extends Object

This class holds a value of type @{param T} that can be in one of 3 states: - It has a concrete value, or - It is missing, or - It is meant to reset any other when it is composed with it. It is mainly used in template composition to capture the case when the user wished to reset any previous values.

Method Summary

Modifier and Type	Method	Description
static <T> ResettableValue<T>	create(T value)	Wraps a value, if the value is null, it returns undefined()
boolean	equals(Object o)
T	get()
int	hashCode()
static ToXContent.Params	hideResetValues(ToXContent.Params params)
boolean	isDefined()
<U> ResettableValue<U>	map(Function<? super T,? extends U> mapper)
<U> U	mapAndGet(Function<? super T,? extends U> f)	Gets the value and applies the function when the value is not null.
static <T> ResettableValue<T>	merge(ResettableValue<T> initial, ResettableValue<T> update, BiFunction<T,T,T> mergeFunction)	Ιt merges the values of the ResettableValue's when they are defined using the provided mergeFunction.
static <T> ResettableValue<T>	reset()
static boolean	shouldDisplayResetValue(ToXContent.Params params)
boolean	shouldReset()
String	toString()
XContentBuilder	toXContent(XContentBuilder builder, ToXContent.Params params, String field)
<U> XContentBuilder	toXContent(XContentBuilder builder, ToXContent.Params params, String field, Function<T,U> transformValue)
static <T> ResettableValue<T>	undefined()

Methods inherited from class java.lang.Object

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

Method Details

reset

public static <T> ResettableValue<T> reset()

Returns:

the reset state, meaning that this value is explicitly requested to be reset

undefined

public static <T> ResettableValue<T> undefined()

Returns:

the undefined state, meaning that this value has not been specified

create

public static <T> ResettableValue<T> create(T value)

Wraps a value, if the value is null, it returns undefined()

shouldReset

public boolean shouldReset()

Returns:

true if the state of this is reset

isDefined

public boolean isDefined()

Returns:

true when the value is defined, either with a concrete value or reset.

get

@Nullable
public T get()

Returns:

the concrete value or null if it is in undefined or reset states.

mapAndGet

public <U> U mapAndGet(Function<? super T,? extends U> f)

Gets the value and applies the function when the value is not null. Slightly more efficient than this.map(f).get().

map

public <U> ResettableValue<U> map(Function<? super T,? extends U> mapper)

merge

public static <T> ResettableValue<T> merge(ResettableValue<T> initial,
 ResettableValue<T> update,
 BiFunction<T,T,T> mergeFunction)

Ιt merges the values of the ResettableValue's when they are defined using the provided mergeFunction.

toXContent

public XContentBuilder toXContent(XContentBuilder builder,
 ToXContent.Params params,
 String field)
                           throws IOException

Throws:

IOException

toXContent

public <U> XContentBuilder toXContent(XContentBuilder builder,
 ToXContent.Params params,
 String field,
 Function<T,U> transformValue)
                               throws IOException

Throws:

IOException

shouldDisplayResetValue

public static boolean shouldDisplayResetValue(ToXContent.Params params)

hideResetValues

public static ToXContent.Params hideResetValues(ToXContent.Params params)

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object