MapTransformer (Apache Commons Collections 4.2 API)

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

All Methods Static Methods Instance Methods Concrete Methods
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 Detail
  - 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
  - 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
  - getMap
```
public Map<? super I,? extends O> getMap()
```
    Gets the map to lookup in.
    
    Returns:
    
    the map
    
    Since:
    
    3.1