scala开发环境搭建和spark入门

1. 下载scala并配置环境变量

下载链接 https://www.scala-lang.org/download/2.10.7.html
配置内容

 %SCALA_HOME%    D:ENVscala-2.10.7
 %PATH%           %SCALA_HOME%bin

配置完成后命令行输入scala返回版本信息

2.下载IDEA并安装scala插件

eclipse插件对scala支持不怎么友好，建议使用idea
下载链接 https://www.jetbrains.com/idea/download/#section=windows

安装插件步骤

File –> Setting –> Plugin –> 输入scala –> Install –> Restart

3新建项目

scala的sbt和maven差不多，直接使用maven就可以管理scala项目

File –> New –> Project –> maven

4.设置项目参数

File –> Project Structure –>global libraries

4.1设置快捷键位eclipse风格

在弹出的setting页面中左侧导航中选择Keymap；在keymaps下拉列表中选择Eclipse

5.Hello world

new –> Scala class -> object

scala和java大致对应关系
    object --> static class
    class  --> class
    trait  -> interface

6.设置hadoop_home

下载链接 https://github.com/srccodes/hadoop-common-2.2.0-bin

 %HADOOP_HOME%   D:ENVhadoop-common-2.2.0-bin
 %PATH%           %HADOOP_HOME%bin

7.本地就可以跑spark worldcount了

<dependencies>
           <dependency>
               <groupId>org.scala-lang</groupId>
               <artifactId>scala-library</artifactId>
               <version>${scala.version}</version>
           </dependency>
           <dependency>
               <groupId>org.apache.spark</groupId>
               <artifactId>spark-core_2.11</artifactId>
               <version>${spark.version}</version>
           </dependency>
           <dependency>
               <groupId>org.apache.spark</groupId>
               <artifactId>spark-streaming_2.11</artifactId>
               <version>${spark.version}</version>
           </dependency>
       </dependencies>

def main(args: Array[String]): Unit = {
    val conf = new SparkConf().setAppName("SparkWorldCount").setMaster("local[4]")
    val sc = new SparkContext(conf)
    val line = sc.textFile("doc/md/环境搭建.md")
    line.flatMap(_.split(" ")).map((_,1)).reduceByKey(_+_).collect().foreach(println)
    sc.stop()
  }