Package com.google.common.collect

Interface Maps.EntryTransformer<K extends @Nullable java.lang.Object,V1 extends @Nullable java.lang.Object,V2 extends @Nullable java.lang.Object>

Type Parameters:

K - the key type of the input and output entries

V1 - the value type of the input entry

V2 - the value type of the output entry

Enclosing class:

Maps

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface Maps.EntryTransformer<K extends @Nullable java.lang.Object,V1 extends @Nullable java.lang.Object,V2 extends @Nullable java.lang.Object>

A transformation of the value of a key-value pair, using both key and value as inputs. To apply the transformation to a map, use Maps.transformEntries(Map, EntryTransformer).

Since:

7.0

Method Summary

Modifier and Type	Method	Description
V2	transformEntry(K key, V1 value)	Determines an output value based on a key-value pair.

Method Detail

transformEntry

V2 transformEntry(K key,
                  V1 value)

Determines an output value based on a key-value pair. This method is generally expected, but not absolutely required, to have the following properties:

• Its execution does not cause any observable side effects.
• The computation is consistent with equals; that is, Objects.equal(k1, k2) && Objects.equal(java.lang.Object, java.lang.Object)(v1, v2) implies that Objects.equal(transformer.transform(k1, v1), transformer.transform(k2, v2)).

Throws:

java.lang.NullPointerException - if the key or value is null and this transformer does not accept null arguments