[置顶] Flink WordCount实例讲解

    摘要：本文主要讲了一个Flink的简单的可以本地运行的wordCount程序

本文工程下载：https://github.com/appleappleapple/BigDataLearning

1、工程目录结构

2、pom文件

<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.lin</groupId>
<artifactId>Flink-Demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>${project.artifactId}</name>

<properties>
<maven.compiler.source>1.6</maven.compiler.source>
<maven.compiler.target>1.6</maven.compiler.target>
<encoding>UTF-8</encoding>
<scala.version>2.11.5</scala.version>
<scala.compat.version>2.11</scala.compat.version>
</properties>

<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>

<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-scala_2.11</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-clients_2.11</artifactId>
<version>1.1.2</version>
</dependency>

<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-scala_2.11</artifactId>
<version>1.1.2</version>
</dependency>
</dependencies>

<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<!-- see http://davidb.github.com/scala-maven-plugin -->
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.0</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
<configuration>
<args>
<arg>-make:transitive</arg>
<arg>-dependencyfile</arg>
<arg>${project.build.directory}/.scala_dependencies</arg>
</args>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<useFile>false</useFile>
<disableXmlReport>true</disableXmlReport>
<!-- If you have classpath issue like NoDefClassError,... -->
<!-- useManifestOnlyJar>false</useManifestOnlyJar -->
<includes>
<include>**/*Test.*</include>
<include>**/*Suite.*</include>
</includes>
</configuration>
</plugin>
</plugins>
</build>
</project>

3、代码

package com.lin.flink.demoimport org.apache.flink.api.java.utils.ParameterToolimport org.apache.flink.api.scala._import org.apache.flink.core.fs.FileSystem.WriteMode/** * 可以直接本地运行 */object WordCount {  def main(args: Array[String]) {    val env = ExecutionEnvironment.createLocalEnvironment(1)    //从本地读取文件    val text = env.readTextFile("D:/Java/flink-1.2.0-bin-hadoop27-scala_2.11/flink-1.2.0-bin-hadoop27-scala_2.11/flink-1.2.0/README.txt")    //单词统计    val counts = text.flatMap { _.toLowerCase.split("\\W+") filter { _.nonEmpty } }      .map { (_, 1) }      .groupBy(0)      .sum(1)    //输出结果    counts.print()    //保存结果到txt文件    counts.writeAsText("D:/output.txt", WriteMode.OVERWRITE)    env.execute("Scala WordCount Example")  }}

直接运行，输出结果如下

保存的外部文件

本文工程下载：https://github.com/appleappleapple/BigDataLearning