flink 1.12.0 提示keyBy警告 Symbol keyBy is deprecated. use [[DataStream.keyBy(KeySelector)]] instead
一、问题描述
flink 1.12相对于1.10个别接口有更新，所以，需要依据代码进行微调。例如keyBy方法
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二、问题原因
keyBy方法实现更新，1.12版本
/**
* Groups the elements of a DataStream by the given K key to
* be used with grouped operators like grouped reduce or grouped aggregations.
*/
def keyBy[K: TypeInformation](fun: KeySelector[T, K]): KeyedStream[T, K] = {
val cleanFun = clean(fun)
val keyType: TypeInformation[K] = implicitly[TypeInformation[K]]
asScalaStream(new JavaKeyedStream(stream, cleanFun, keyType))
}
进一步探究KeySelector
/*
* 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.flink.api.java.functions;
import org.apache.flink.annotation.Public;
import org.apache.flink.api.common.functions.Function;
import java.io.Serializable;
/**
* The {@link KeySelector} allows to use deterministic objects for operations such as
* reduce, reduceGroup, join, coGroup, etc. If invoked multiple times on the same object,
* the returned key must be the same.
*
* <p>The extractor takes an object and returns the deterministic key for that object.
*
* @param <IN> Type of objects to extract the key from.
* @param <KEY> Type of key.
*/
@Public
@FunctionalInterface
public interface KeySelector<IN, KEY> extends Function, Serializable {
/**
* User-defined function that deterministically extracts the key from an object.
*
* <p>For example for a class:
* <pre>
* public class Word {
* String word;
* int count;
* }
* </pre>
* The key extractor could return the word as
* a key to group all Word objects by the String they contain.
*
* <p>The code would look like this
* <pre>
* public String getKey(Word w) {
* return w.word;
* }
* </pre>
*
* @param value The object to get the key from.
* @return The extracted key.
*
* @throws Exception Throwing an exception will cause the execution of the respective task to fail,
* and trigger recovery or cancellation of the program.
*/
KEY getKey(IN value) throws Exception;
}
三、解决实例
//1.10
val Stream1: KeyedStream[behavior, Tuple] = dataStream
.keyBy("name")
替换为
//1.12
valStream2: KeyedStream[behavior, Long] = dataStream
.keyBy(data => data.name)
