| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.kafka.streams.kstream; |
| |
| /** |
| * The Aggregator interface for aggregating values of the given key. |
| * |
| * @param <K> key type |
| * @param <V> original value type |
| * @param <T> aggregate value type |
| */ |
| public interface Aggregator<K, V, T> { |
| |
| T apply(K aggKey, V value, T aggregate); |
| } |
