Flink 1.16.0 wordCount示例，入门案例

环境准备

JAVA1.8

新建maven工程

引入依赖

<dependencies>

        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-streaming-javaartifactId>
            <version>1.16.0version>
        dependency>

        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-clientsartifactId>
            <version>1.16.0version>
        dependency>

        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-runtimeartifactId>
            <version>1.16.0version>
        dependency>

    dependencies>

示例代码

import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.operators.AggregateOperator;
import org.apache.flink.api.java.operators.DataSource;
import org.apache.flink.api.java.operators.FlatMapOperator;
import org.apache.flink.api.java.operators.UnsortedGrouping;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;

public class FlinkApp {

   public static void main(String[] args) {

       // 创建执行环境
       ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();


       // 从文件中读取数据
       DataSource<String> lineDataSource = env.readTextFile("E:\\input\\words.txt");

       // 切分数据
       FlatMapOperator<String, Tuple2<String, Long>> wordAndOneTuple = lineDataSource.flatMap((String line, Collector<Tuple2<String, Long>> out) -> {

           String[] words = line.split(" ");
           for (String word : words) {
               out.collect(Tuple2.of(word, 1L));
           }

       }).returns(Types.TUPLE(Types.STRING, Types.LONG));

       UnsortedGrouping<Tuple2<String, Long>> wordAndOneGroup = wordAndOneTuple.groupBy(0);

       // 分组内进行聚合统计
       AggregateOperator<Tuple2<String, Long>> sum = wordAndOneGroup.sum(1);

       try {
           sum.print();
       } catch (Exception e) {
           e.printStackTrace();
       }
   }
}

文件内容示例：

hello world
hello flink
hello java

运行结果：

项目结构