mjsax commented on a change in pull request #9107: URL: https://github.com/apache/kafka/pull/9107#discussion_r564768542
########## File path: streams/src/main/java/org/apache/kafka/streams/kstream/Branched.java ########## @@ -0,0 +1,149 @@ +/* + * 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; + +import java.util.Objects; +import java.util.function.Consumer; +import java.util.function.Function; + +/** + * The {@code Branched} class is used to define the optional parameters when building branches with + * {@link BranchedKStream}. + * + * @param <K> type of record key + * @param <V> type of record value + */ +public class Branched<K, V> implements NamedOperation<Branched<K, V>> { + + protected final String name; + protected final Function<? super KStream<K, V>, ? extends KStream<K, V>> chainFunction; + protected final Consumer<? super KStream<K, V>> chainConsumer; + + protected Branched(final String name, + final Function<? super KStream<K, V>, ? extends KStream<K, V>> chainFunction, + final Consumer<? super KStream<K, V>> chainConsumer) { + this.name = name; + this.chainFunction = chainFunction; + this.chainConsumer = chainConsumer; + } + + /** + * Create an instance of {@code Branched} with provided branch name suffix. + * + * @param name the branch name suffix to be used. If {@code null}, a default branch name suffix will be generated + * (see {@link BranchedKStream} description for details) + * @param <K> key type + * @param <V> value type + * @return a new instance of {@code Branched} + */ + public static <K, V> Branched<K, V> as(final String name) { + return new Branched<>(name, null, null); + } + + /** + * Create an instance of {@code Branched} with provided chain function. + * + * @param chain A function that will be applied to the branch. If the provided function returns + * {@code null}, its result is ignored, otherwise it is added to the {@code Map} returned + * by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see + * {@link BranchedKStream} description for details). + * @param <K> key type + * @param <V> value type + * @return a new instance of {@code Branched} + */ + public static <K, V> Branched<K, V> withFunction( + final Function<? super KStream<K, V>, ? extends KStream<K, V>> chain) { + Objects.requireNonNull(chain, "chain function should not be null"); + return new Branched<>(null, chain, null); + } + + /** + * Create an instance of {@code Branched} with provided chain consumer. + * + * @param chain A consumer to which the branch will be sent. If a consumer is provided here, + * the respective branch will not be added to the resulting {@code Map} returned + * by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see + * {@link BranchedKStream} description for details). + * @param <K> key type + * @param <V> value type + * @return a new instance of {@code Branched} + */ + public static <K, V> Branched<K, V> withConsumer(final Consumer<KStream<K, V>> chain) { + Objects.requireNonNull(chain, "chain consumer should not be null"); + return new Branched<>(null, null, chain); + } + + /** + * Create an instance of {@code Branched} with provided chain function and branch name suffix. + * + * @param chain A function that will be applied to the branch. If {@code null}, the identity + * {@code kStream -> kStream} function will be used. If the provided function returns + * {@code null}, its result is ignored, otherwise it is added to the {@code Map} returned + * by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see + * {@link BranchedKStream} description for details). + * @param name the branch name suffix to be used. If {@code null}, a default branch name suffix will be generated + * (see {@link BranchedKStream} description for details) + * @param <K> key type + * @param <V> value type + * @return a new instance of {@code Branched} + */ + public static <K, V> Branched<K, V> withFunction( + final Function<? super KStream<K, V>, ? extends KStream<K, V>> chain, final String name) { + Objects.requireNonNull(chain, "chain function should not be null"); + return new Branched<>(name, chain, null); + } + + /** + * Create an instance of {@code Branched} with provided chain consumer and branch name suffix. + * + * @param chain A consumer to which the branch will be sent. If a non-null consumer is provided here, + * the respective branch will not be added to the resulting {@code Map} returned + * by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see + * {@link BranchedKStream} description for details). + * @param name the branch name suffix to be used. If {@code null}, a default branch name suffix will be generated + * (see {@link BranchedKStream} description for details) + * @param <K> key type + * @param <V> value type + * @return a new instance of {@code Branched} + */ + public static <K, V> Branched<K, V> withConsumer(final Consumer<? super KStream<K, V>> chain, + final String name) { + Objects.requireNonNull(chain, "chain consumer should not be null"); Review comment: nit: `should not` -> `cannot` (or `can't` if you prefer) ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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