Flink-01 介绍Flink Java 3分钟上手 HelloWorld 和 Stream ExecutionEnvironment DataSet FlatMapFunction

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>flink-demo-01</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <flink.version>1.13.2</flink.version> <!-- 确保版本号正确 -->
        <scala.binary.version>2.12</scala.binary.version> <!-- 确保Scala版本正确 -->
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>
</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-java_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-clients_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
        </dependency>
    </dependencies>
</project>

package icu.wzk.demo01;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.util.Collector;
import org.apache.flink.api.java.tuple.Tuple2;


public class StartApp {

    public static void main(String[] args) throws Exception {
        String inPath = "demo01/file.txt";
        String outputPath = "demo01/result.csv";
        ExecutionEnvironment executionEnvironment = ExecutionEnvironment.getExecutionEnvironment();
        DataSet<String> text = executionEnvironment.readTextFile(inPath);
        DataSet<Tuple2<String, Integer>> dataSet = text
                .flatMap(new LineSplitter())
                .groupBy(0)
                .sum(1);
        dataSet
                .writeAsCsv(outputPath,"\n"," ", FileSystem.WriteMode.OVERWRITE)
                .setParallelism(1);
        executionEnvironment.execute("file.txt -> result.csv");
    }

    static class LineSplitter implements FlatMapFunction<String, Tuple2<String,Integer>> {
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> collector) throws Exception {
            for (String word : line.split(" ")) {
                collector.collect(new Tuple2<>(word,1));
            }
        }
    }
}

The narrator introduces himself as a man who learned when he was a child that adults lack imagination and understanding. He is now a pilot who has crash-landed in a desert. He encounters a small boy who asks him for a drawing of a sheep, and the narrator obliges. The narrator, who calls the child the little prince, learns that the boy comes from a very small planet, which the narrator believes to be asteroid B-612. Over the course of the next few days, the little prince tells the narrator about his life. On his asteroid-planet, which is no bigger than a house, the prince spends his time pulling up baobab seedlings, lest they grow big enough to engulf the tiny planet. One day an anthropomorphic rose grows on the planet, and the prince loves her with all his heart. However, her vanity and demands become too much for the prince, and he leaves.
The prince travels to a series of asteroids, each featuring a grown-up who has been reduced to a function. The first is a king who requires obedience but has no subjects until the arrival of the prince. The sole inhabitant of the next planet is a conceited man who wants nothing from the prince but flattery. The prince subsequently meets a drunkard, who explains that he must drink to forget how ashamed he is of drinking. The fourth planet introduces the prince to a businessman, who maintains that he owns the stars, whih makes it very important that he know exactly how many stars there are. The prince then encounters a lamplighter, who follows orders that require him to light a lamp each evening and put it out each morning, even though his planet spins so fast that dusk and dawn both occur once every minute. Finally the prince comes to a planet inhabited by a geographer. The geographer, however, knows nothing of his own planet, because it is his sole function to record what he learns from explorers. He asks the prince to describe his home planet, but when the prince mentions the flower, the geographer says that flowers are not recorded because they are ephemeral. The geographer recommends that the little prince visit Earth.
On Earth the prince meets a snake, who says that he can return him to his home, and a flower, who tells him that people lack roots. He comes across a rose garden, and he finds it very depressing to learn that his beloved rose is not, as she claimed, unique in the universe. A fox then tells him that if he tames the fox—that is, establishes ties with the fox—then they will be unique and a source of joy to each other.
The narrator and little prince have now spent eight days in the desert and have run out of water. The two then traverse the desert in search of a well, which, miraculously, they find. The little prince tells the narrator that he plans to return that night to his planet and flower and that now the stars will be meaningful to the narrator, because he will know that his friend is living on one of them. Returning to his planet requires allowing the poisonous snake to bite him. The story resumes six years later. The narrator says that the prince’s body was missing in the morning, so he knows that he returned to his planet, and he wonders whether the sheep that he drew him ate his flower. He ends by imploring the reader to contact him if they ever spot the little prince.

and 15
are. 1
baobab 1
be 3
bigger 1
body 1
calls 1
days, 1
demands 1
describe 1
drinking. 1
drunkard, 1
enough 1
featuring 1
function 1
know 2
knows 2
learns 2
little 6