org.apache.kafka.streams.kstream

Interface Aggregator<K,V,T>

Type Parameters:

K - key type

V - original value type

T - aggregate value type

public interface Aggregator<K,V,T>

The Aggregator interface for aggregating values of the given key.

Method Summary

Modifier and Type	Method and Description
T	apply(K aggKey, V value, T aggregate) Compute a new aggregate from the key and value of a record and the current aggregate of the same key.

Method Detail

apply

T apply(K aggKey,
        V value,
        T aggregate)

Compute a new aggregate from the key and value of a record and the current aggregate of the same key.

Parameters:

aggKey - the key of the record

value - the value of the record

aggregate - the current aggregate value

Returns:

the new aggregate value