Flink开发环境搭建（maven）

1、下载scala sdk

http://www.scala-lang.org/download/ 直接到这里下载sdk，(https://downloads.lightbend.com/scala/2.12.8/scala-2.12.8.msi)

2、下载scala for intellij idea的插件

File->setting->plugins里搜索Scala，然后安装即可

3、https://maven.apache.org/download.cgi

http://mirrors.shu.edu.cn/apache/maven/maven-3/3.6.0/binaries/apache-maven-3.6.0-bin.zip

4、生成工程

mvn archetype:generate -DarchetypeGroupId=org.apache.flink -DarchetypeArtifactId=flink-quickstart-scala

或者

mvn archetype:generate -DarchetypeGroupId=org.apache.flink -DarchetypeArtifactId=flink-quickstart-java -DarchetypeCatalog=https://repository.apache.org/content/repositories/snapshots/ -DarchetypeVersion=1.7-SNAPSHOT

5、scala统计词频示例

package com.test.s

import org.apache.flink.api.scala._

object WordCount {

  def main(args: Array[String]) {

    val env = ExecutionEnvironment.getExecutionEnvironment

    // get input data
    val text = env.readTextFile("D:\git\test\pom.xml")

    val counts = text.flatMap { _.toLowerCase.split("\W+") filter { _.nonEmpty } }
      .map { (_, 1) }
      .groupBy(0)
      .sum(1)

    // counts.writeAsCsv("D:\git\test\output.txt", "
", " ")
    counts.print()
    env.execute("Socket Window WordCount")

  }
}

直接按照样例执行，可能出现以下错误：

Exception in thread "main" java.lang.RuntimeException: No new data sinks have been defined since the last execution. The last execution refers to the latest call to 'execute()', 'count()', 'collect()', or 'print()'.

参照此文，原因是print()方法自动会调用execute()方法，造成错误，所以注释掉env.execute()即可