wordCount5 （combineByKey)

package com.atguigu

import org.apache.spark.rdd.RDD
import org.apache.spark.{HashPartitioner, Partitioner, SparkConf, SparkContext}

object Trans {
  def main(args: Array[String]): Unit = {

    val conf: SparkConf = new SparkConf().setMaster("local[*]").setAppName("Spark01_Partition")

    //构建spark上下文对象
    val sc = new SparkContext(conf)

    val rdd: RDD[(String, Int)] = sc.makeRDD(Array(("a",1),("b",2),("a",3),("b",4),("a",5)))

    val rdd1: RDD[(String, Int)] = rdd.combineByKey(
      (num: Int) => num,
      (x: Int, y: Int) => {
        x + y
      },
      (x: Int, y: Int) => {
        x + y
      }
    )
    rdd1.collect().foreach(println)
    sc.stop()
  }
}

(a,9)
(b,6)