Package org.apache.commons.collections4.functors

Class IfTransformer<T,R>

java.lang.Object

org.apache.commons.collections4.functors.IfTransformer<T,R>

Type Parameters:

T - the type of the input to the function.

R - the type of the result of the function.

All Implemented Interfaces:

Serializable, Function<T,R>, Transformer<T,R>

public class IfTransformer<T,R>
extends Object
implements Transformer<T,R>, Serializable

Transformer implementation that will call one of two closures based on whether a predicate evaluates as true or false.

Since:

4.1

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
IfTransformer(Predicate<? super T> predicate, Transformer<? super T,? extends R> trueTransformer, Transformer<? super T,? extends R> falseTransformer)	Constructor that performs no validation.

Method Summary

Modifier and Type	Method	Description
Transformer<? super T,? extends R>	getFalseTransformer()	Gets the transformer used when false.
Predicate<? super T>	getPredicate()	Gets the predicate.
Transformer<? super T,? extends R>	getTrueTransformer()	Gets the transformer used when true.
static <I, O> Transformer<I,O>	ifTransformer(Predicate<? super I> predicate, Transformer<? super I,? extends O> trueTransformer, Transformer<? super I,? extends O> falseTransformer)	Factory method that performs validation.
static <T> Transformer<T,T>	ifTransformer(Predicate<? super T> predicate, Transformer<? super T,? extends T> trueTransformer)	Factory method that performs validation.
R	transform(T input)	Transforms the input using the true or false transformer based to the result of the predicate.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.Function

andThen, compose

Methods inherited from interface org.apache.commons.collections4.Transformer

apply

Constructor Details

IfTransformer

public IfTransformer(Predicate<? super T> predicate,
 Transformer<? super T,? extends R> trueTransformer,
 Transformer<? super T,? extends R> falseTransformer)

Constructor that performs no validation. Use the static factory method ifTransformer if you want that.

Parameters:

predicate - predicate to switch on, not null

trueTransformer - transformer used if true, not null

falseTransformer - transformer used if false, not null

Method Details

ifTransformer

public static <I,
O> Transformer<I,O> ifTransformer(Predicate<? super I> predicate,
 Transformer<? super I,? extends O> trueTransformer,
 Transformer<? super I,? extends O> falseTransformer)

Factory method that performs validation.

Type Parameters:

I - input type for the transformer

O - output type for the transformer

Parameters:

predicate - predicate to switch on

trueTransformer - transformer used if true

falseTransformer - transformer used if false

Returns:

the if transformer

Throws:

NullPointerException - if either argument is null

ifTransformer

public static <T> Transformer<T,T> ifTransformer(Predicate<? super T> predicate,
 Transformer<? super T,? extends T> trueTransformer)

Factory method that performs validation.

This factory creates a transformer that just returns the input object when the predicate is false.

Type Parameters:

T - input and output type for the transformer

Parameters:

predicate - predicate to switch on

trueTransformer - transformer used if true

Returns:

the if transformer

Throws:

NullPointerException - if either argument is null

getFalseTransformer

public Transformer<? super T,? extends R> getFalseTransformer()

Gets the transformer used when false.

Returns:

the transformer

getPredicate

public Predicate<? super T> getPredicate()

Gets the predicate.

Returns:

the predicate

getTrueTransformer

public Transformer<? super T,? extends R> getTrueTransformer()

Gets the transformer used when true.

Returns:

the transformer

transform

public R transform(T input)

Transforms the input using the true or false transformer based to the result of the predicate.

Specified by:

transform in interface Transformer<T,R>

Parameters:

input - the input object to transform

Returns:

the transformed result