MapValuesOperator

package com.bjsxt.scala.spark.operator

import org.apache.spark.SparkConf
import org.apache.spark.SparkContext
import org.apache.spark.HashPartitioner

object MapValuesOperator {
  def main(args: Array[String]): Unit = {
    val sparkConf = new SparkConf().setAppName("MapValuesOperator")
      .setMaster("local")
    val sc = new SparkContext(sparkConf)
    val links = sc.parallelize(List(("A", "Q"), ("B", "w"), ("C", "r"), ("D", "T")))
    //mapValues  只遍历value   mapValues必须作用在KV格式的RDD
    var ranks = links.mapValues(v => 1.0)
    //collect会将ranks这个RDD的计算结果拉回到Driver端
    val results = ranks.collect()
    for (result <- results) {
      println(result)
    }
    sc.stop()
  }
}