com.tangosol.util

Interface MapEventTransformer<K,V,U>

All Superinterfaces:

Serializable

All Known Implementing Classes:

ExtractorEventTransformer, MapEventTransformerFilter, SamplingEventTransformer, SemiLiteEventTransformer

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 interface MapEventTransformer<K,V,U>
extends Serializable

MapEventTransformer interface is used to allow an event consumer to change the content of a MapEvent destined for the corresponding MapListener.

In general, the transform method is called after the original MapEvent is evaluated by a Filter (such as MapEventFilter). The values contained by the returned MapEvent object will be the ones given (sent) to the corresponding listener. Returning null will prevent the emission of the event altogether.

Note: Currently, the MapEventTransformer interface is supported only by partitioned caches.

Since:

Coherence 3.4

Author:

gg/jh 2008.05.01

Method Summary

Modifier and Type	Method and Description
default <T> MapEventTransformer<K,V,T>	andThen(MapEventTransformer<K,U,T> after) Returns a composed MapEventTransformer that performs, in sequence, this transformation followed by the after transformation.
MapEvent<K,U>	transform(MapEvent<K,V> event) Transform the specified MapEvent.

Method Detail

transform

MapEvent<K,U> transform(MapEvent<K,V> event)

Transform the specified MapEvent. The values contained by the returned MapEvent object will be the ones given (sent) to the corresponding listener.

Parameters:

event - the original MapEvent object

Returns:

modified MapEvent object or null to discard the event

andThen

default <T> MapEventTransformer<K,V,T> andThen(MapEventTransformer<K,U,T> after)

Returns a composed MapEventTransformer that performs, in sequence, this transformation followed by the after transformation.

If performing either transformation throws an exception, it is relayed to the caller of the composed operation. If performing this transformation throws an exception, the after transformation will not be performed.

Parameters:

after - the transformation to perform after this transformation

Returns:

a composed MapEventTransformer that performs in sequence this transformation followed by the after transformation