下载并且解压Flink

Downloads | Apache Flink

启动Flink.

$ ./bin/start-cluster.sh
Starting cluster.
Starting standalonesession daemon on host DESKTOP-T4TU7JE.
Starting taskexecutor daemon on host DESKTOP-T4TU7JE.

Flink 的版本附带了许多示例作业。您可以快速将这些应用程序之一部署到正在运行的集群。

$ ./bin/flink run examples/streaming/WordCount.jar
$ tail log/flink-*-taskexecutor-*.out(nymph,1)(in,3)(thy,1)(orisons,1)(be,4)(all,2)(my,1)(sins,1)(remember,1)(d,4)

Stop Flink

$ ./bin/stop-cluster.sh

利用java 代码运行第一个flink hello world.

pom.xml

        <dependency><groupId>org.apache.flink</groupId><artifactId>flink-java</artifactId><version>${flink.version}</version></dependency><dependency><groupId>org.apache.flink</groupId><artifactId>flink-streaming-java_2.12</artifactId><version>${flink.version}</version></dependency>

java 代码

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;public class HelloWorld {public static void main(String[] args) throws Exception {// Set up the execution environmentfinal StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();// Create a stream of dataDataStream<String> dataStream = env.fromElements("Hello", "World", "Flink");// Apply transformation: split each word by spaceDataStream<Tuple2<String, Integer>> wordCounts = dataStream.flatMap(new Splitter()).keyBy(0).sum(1);// Print the resultwordCounts.print();// Execute the Flink jobenv.execute("Hello World Example");}// Custom FlatMapFunction to split each sentence into wordspublic static final class Splitter implements FlatMapFunction<String, Tuple2<String, Integer>> {@Overridepublic void flatMap(String sentence, Collector<Tuple2<String, Integer>> out) {// Split the sentence into wordsfor (String word : sentence.split(" ")) {// Emit the word with a count of 1out.collect(new Tuple2<>(word, 1));}}}
}

参考

Local Installation | Apache Flink