代码仓库

会同步代码到 GitHub
https://github.com/turbo-duck/flink-demo

当前章节

继续上一节的内容：https://blog.csdn.net/w776341482/article/details/139875037

上一节中，我们需要使用 nc 或者 telnet 等工具来模拟 Socket 流。这节我们写一个 ServerSocket 来模拟这些 操作，让流自动的写入不用我们手动去操作了。

POM.xml

与上一节一致，不需要修改

编写代码

还是和上一节一样的 Socket 流，这里略去其他的代码

DataStreamSource<String> textStream = streamExecutionEnvironment.socketTextStream(ip, port, "\n");

FlinkServer

继承 Thread 启动一个线程来进行Flink的服务

package icu.wzk.demo03;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.windowing.assigners.SlidingProcessingTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.util.Collector;

public class FlinkServer extends Thread {

    @Override
    public void run() {
        String ip = "0.0.0.0";
        int port = 9999;
        StreamExecutionEnvironment streamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment();
        DataStreamSource<String> textStream = streamExecutionEnvironment.socketTextStream(ip, port, "\n");
        SingleOutputStreamOperator<Tuple2<String, Long>> tuple2SingleOutputStreamOperator = textStream.flatMap(new FlatMapFunction<String, Tuple2<String, Long>>() {
            @Override
            public void flatMap(String s, Collector<Tuple2<String, Long>> collector) throws Exception {
                String[] splits = s.split("\\s");
                for (String word : splits) {
                    collector.collect(Tuple2.of(word, 1L));
                }
            }
        });
        SingleOutputStreamOperator<Tuple2<String, Long>> word = tuple2SingleOutputStreamOperator
                .keyBy(new KeySelector<Tuple2<String, Long>, Object>() {
                    @Override
                    public Object getKey(Tuple2<String, Long> stringLongTuple2) throws Exception {
                        return stringLongTuple2.f0;
                    }
                })
                .window(SlidingProcessingTimeWindows.of(Time.seconds(5), Time.seconds(1)))
                .sum(1);
        System.out.println("wait word print()");
        word.print();
        try {
            streamExecutionEnvironment.execute("stream!");
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

NumRandom

使用 ServerSocket 实现一个持续的流输出

package icu.wzk.demo03;

import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;

public class RandomNumClient extends Thread {

    @Override
    public void run() {
        String ip = "0.0.0.0";
        int port = 9999;
        try {
            ServerSocket serverSocket = new ServerSocket();
            InetSocketAddress address = new InetSocketAddress(ip, port);
            serverSocket.bind(address);
            Socket socket = serverSocket.accept();
            OutputStream output = socket.getOutputStream();
            PrintWriter writer = new PrintWriter(output, true);
            Random random = new Random();
            for (int i = 0; i < 500; i ++) {
                int randomNumber = random.nextInt(10) + 1;
                writer.println(randomNumber);
                System.out.println("ServerSocket Send To Flink: " + randomNumber);
                Thread.sleep(200);
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

}

StartApp

将上述的两个类组装起来

package icu.wzk.demo03;


public class StartApp {

    public static void main(String[] args) throws Exception {
        RandomNumClient randomNumClient = new RandomNumClient();
        FlinkServer flinkServer = new FlinkServer();
        flinkServer.start();
        randomNumClient.start();
    }

}