Maven开发Spark程序

将src/main/java改名为src/main/scala
修改pom.xml
pom.xml

    4.0.0

    com.example
    sparkTest
    1.0-SNAPSHOT
    
        
            org.scala-lang
            scala-library
            2.11.8
        
        
        
            org.apache.spark
            spark-core_2.12
            3.1.2
        

        
        
            org.apache.hadoop
            hadoop-client
            3.3.0
        
    

引入scala依赖
File->Project Structure


这样scala目录就可以创建scala文件了。

wordCount

package com.example

import org.apache.spark.{SparkConf, SparkContext}

object wordCount {
  def main(args: Array[String]): Unit = {
    val conf=new SparkConf()
    conf.setAppName("MyFirstSparkApplication")
    conf.setMaster("yarn")
    val sc=new SparkContext(conf)
    val data=sc.textFile(args(0))
    val words=data.flatMap(_.split("n")).flatMap(_.split(" ")).map((_,1)).reduceByKey(_+_).collect()
    words foreach println
  }
}

IDEA打包
File->Project Structure






集群上运行

spark-submit --master yarn --name wordCount --class com.example.wordCount hdfs:///sparkTest.jar /user/hadoop/input

其中/user/hadoop/input为hdfs路径。