Package org.apache.commons.collections4.functors

Class MapTransformer<I,O>

java.lang.Object

org.apache.commons.collections4.functors.MapTransformer<I,O>

All Implemented Interfaces:

Serializable, Transformer<I,O>

public final class MapTransformer<I,O>
extends Object
implements Transformer<I,O>, Serializable

Transformer implementation that returns the value held in a specified map using the input parameter as a key.

Since:

3.0

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
Map<? super I,? extends O>	getMap()	Gets the map to lookup in.
static <I, O> Transformer<I,O>	mapTransformer(Map<? super I,? extends O> map)	Factory to create the transformer.
O	transform(I input)	Transforms the input to result by looking it up in a Map.

Methods inherited from class java.lang.Object

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

Method Details

mapTransformer

public static <I,
O> Transformer<I,O> mapTransformer(Map<? super I,? extends O> map)

Factory to create the transformer.

If the map is null, a transformer that always returns null is returned.

Type Parameters:

I - the input type

O - the output type

Parameters:

map - the map, not cloned

Returns:

the transformer

getMap

public Map<? super I,? extends O> getMap()

Gets the map to lookup in.

Returns:

the map

Since:

3.1

transform

public O transform(I input)

Transforms the input to result by looking it up in a Map.

Specified by:

transform in interface Transformer<I,O>

Parameters:

input - the input object to transform

Returns:

the transformed result