Flink之DataStream API 概述

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前言

flink版本号1.18.1

一、DataStream API 应用实例

public class WordCount {
   
    public static void main(String[] args) throws Exception {
   

        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        DataStreamSource<String> DataStreamSource = env.readTextFile("word.text");
        SingleOutputStreamOperator<Tuple2<String, Long>> wordAndOne = DataStreamSource.flatMap(new FlatMapFunction<String, Tuple2<String, Long>>() {
   
            @Override
            public void flatMap(String value, Collector<Tuple2<String, Long>> out) throws Exception {
   
                String[] words = value.split(" ");

                for (String word : words) {
   
                    out.collect(Tuple2.