Flink的WordCount实现（Java和Scala）

Java实现WordCount

package com.flink.Java;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.tuple.Tuple;
import org.apache.flink.api.java.utils.ParameterTool;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.datastream.WindowedStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.streaming.api.windowing.windows.TimeWindow;
import org.apache.flink.util.Collector;

/**
 * Created by Shi shuai RollerQing on 2019/12/16 15:44
 * 用窗口操作的方式进行WordCount *
 * 需要实现每隔1秒对最近2秒内的数据进行聚合操作
 */
public class WordCount {
    public static void main(String[] args) throws Exception {
        // 获取服务数据的端口号
        int port;
        try {
            ParameterTool parameterTool = ParameterTool.fromArgs(args);
            port = parameterTool.getInt("port");
        } catch (Exception e) {
            System.err.println("No port set . Please use default port 9000");
            port = 6666;
        }

        String hostname = "hadoop01";
        // 初始化对象
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        // 获取数据
        DataStreamSource<String> data = env.socketTextStream(hostname, port);
        // 开始计算
        // 生成一个个元组： (word, 1)
        SingleOutputStreamOperator<WordWithCount> pairWords = data.flatMap(
                new FlatMapFunction<String, WordWithCount>() {
                    @Override
                    public void flatMap(String s, Collector<WordWithCount> out) throws Exception {
                        String[] splits = s.split(" ");
                        for (String word : splits) {
                            out.collect(new WordWithCount(word, 1L));
                        }
                    }
                }
        );

        // 将元组按照key进行分组
        KeyedStream<WordWithCount, Tuple> grouped = pairWords.keyBy("word");

        //调用窗口操作
        //需要给两个重要的参数 窗口长度和滑动间隔
        WindowedStream<WordWithCount, Tuple, TimeWindow> window = grouped.timeWindow(Time.seconds(2), Time.seconds(1));

        SingleOutputStreamOperator<WordWithCount> counts = window.sum("count");

//        window.reduce(new ReduceFunction() {
//            @Override
//            public WordWithCount reduce(WordWithCount value1, WordWithCount value2) throws Exception {
//                return new WordWithCount(value1.word, value1.count + value2.count);
//            }
//        });


        //打印
        counts.print().setParallelism(1);

        env.execute("WordCount");
    }

    public static class WordWithCount {
        public String word;
        public long count;

        public WordWithCount() {
        }

        public WordWithCount(String word, long count) {
            this.word = word;
            this.count = count;
        }

        @Override
        public String toString() {
            return "WordWithCount{" +
                    "word='" + word + '\'' +
                    ", count=" + count +
                    '}';
        }
    }


}

启动hadoop01，输入命令 nc -lk 6666
idea运行时并没有输入参数 所以根据catch处理port被设置为6666

scala

流式WordCount代码实现

package com.flink.demo01
import org.apache.flink.api.java.utils.ParameterTool
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.streaming.api.windowing.time.Time
/**
 * Created by Shi shuai RollerQing on 2019/12/16 19:03
 * 流式WordCount-Scala代码实现
 *
 * 用窗口操作的方式进行WordCount
 */
object WordCount_Scala {
  def main(args: Array[String]): Unit = {
    // 获取NetCat的port
    val port: Int = try {
      ParameterTool.fromArgs(args).getInt("port")
    } catch {
      case e: Exception => {
        System.err.println("No port set, Use default port 6666")
      }
        6666
    }

    // 获取上下文对象（初始化对象）
    val env = StreamExecutionEnvironment.getExecutionEnvironment

    //获取数据
    val data = env.socketTextStream("hadoop01", port)

    // 必须要引入这个包，这里面有很多在计算时用到的一些方法
    import org.apache.flink.api.scala._

    // 进行解析数据，并按照需求进行计算
    val words = data.flatMap(_.split("\\s+")) // 获取数据并进行切分，生成一个个单词
    val tups = words.map(w => WordWithCount(w, 1)) // 将一个个单词生成一个个对偶元组

    val grouped = tups.keyBy("word") // 分组
    //     val grouped = tups.keyBy(0)// 分组

    val window = grouped.timeWindow(Time.seconds(2), Time.seconds(2)) // 调用窗口操作

    //   val res = window.sum("count") // 聚合
    val res = window.reduce((a, b) => WordWithCount(a.word, a.count + b.count))
    // 将结果打印
    res.print.setParallelism(1)
    // 开始执行
    env.execute("scala wordCount")


  }

  case class WordWithCount(word: String, count: Int)

}

批式WordCount代码实现

package com.flink.demo01

import org.apache.flink.api.java.operators.DataSink
import org.apache.flink.api.scala.{DataSet, ExecutionEnvironment}

/**
 * Created by Shi shuai RollerQing on 2019/12/16 19:29
 */
object WordCountB_Scala {
  def main(args: Array[String]): Unit = {
    val env = ExecutionEnvironment.getExecutionEnvironment
    //get input data
    val text: DataSet[String] = env.readTextFile("C:\\Users\\HP\\IdeaProjects\\sparkCore\\data\\test.txt")
    import org.apache.flink.api.scala._
    val counts = text.flatMap(_.toLowerCase.split(" ").filter(_.nonEmpty))
      .map((_, 1))
      .groupBy(0)
      .sum(1)
    counts.collect().foreach(println)
// counts.setParallelism(1).writeAsCsv("C:\\Users\\HP\\IdeaProjects\\sparkCore\\data\\csvwc", "\n", "\t")
//    val write: DataSink[(String, Int)] = counts.setParallelism(1).writeAsCsv("C:\\Users\\HP\\IdeaProjects\\sparkCore\\data\\csvwc", "\n", "\t")
  }
}

为什么运行counts.setParallelism(1).writeAsCsv(“C:\Users\HP\IdeaProjects\sparkCore\data\csvwc”, “\n”, “\t”)这句话没有反应 就是没有对应文件输出？？？

依赖

<properties>   
        <scala.version>2.11.8scala.version>
        <flink.version>1.7.2flink.version>
    properties>

        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-javaartifactId>
            <version>${flink.version}version>
        dependency>
        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-streaming-java_2.11artifactId>
            <version>${flink.version}version>

        dependency>


        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-scala_2.11artifactId>
            <version>${flink.version}version>
        dependency>
        
        <dependency>
            <groupId>org.apache.flinkgroupId>
            <artifactId>flink-streaming-scala_2.11artifactId>
            <version>${flink.version}version>
        dependency>