Flink 流处理 word count

POM 文件。

    <dependencies>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-scala_2.11</artifactId>
            <version>1.10.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-streaming-scala -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-scala_2.11</artifactId>
            <version>1.10.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-connector-kafka-0.11_2.11</artifactId>
            <version>1.10.1</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <!-- 该插件用于将Scala 代码编译成class 文件-->
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.4.6</version>
                <executions>
                    <execution>
                        <!-- 声明绑定到maven 的compile 阶段-->
                        <goals>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.0.0</version>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

源码:

package com.kpwong.wc

import org.apache.flink.api.java.utils.ParameterTool
import org.apache.flink.streaming.api.scala.{DataStream, StreamExecutionEnvironment}
import org.apache.flink.api.scala._


//流处理wordcount
object StreamWordCount {
  def main(args: Array[String]): Unit = {
     //创建流处理的执行环境
      val env: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment
//      env.setParallelism(8)

//     val tool: ParameterTool = ParameterTool.fromArgs(args)
//     val host: String = tool.get("host")
//     val port: Int = tool.getInt("port")

     //接收一个socket 文本流

     val socketDS: DataStream[String] = env.socketTextStream("hadoop202",9999)

     val wcDS: DataStream[(String, Int)] = socketDS
                                           .flatMap(_.split(" "))
                                           .filter(_.nonEmpty).startNewChain()
                                           .map((_,1))
                                           .keyBy(0)
                                           .sum(1)
    wcDS.print()

    //启动任务执行
    env.execute("Stream word count")
  }

}

　运行netcat :

　

 查看结果: