spark--transform算子--reduceByKey

import org.apache.spark.{SparkConf, SparkContext}/**  * Created by liupeng on 2017/6/16.  */object T_reduceByKey {  System.setProperty("hadoop.home.dir","F:\\hadoop-2.6.5")  def main(args: Array[String]): Unit = {    val conf = new SparkConf().setAppName("reduceByKey_test").setMaster("local")    val sc = new SparkContext(conf)    val list1 = List(("liupeng", 120), ("liupeng", 120), ("liusi", 120))    val rdd = sc.parallelize(list1)    //reduceByKey方法用于根据key做分组计算，但是和reduce不同，他还是属于T算子    val sum = rdd.reduceByKey((x, y) => x + y)      .foreach(println)  }}

运行结果：

(liusi,120)
(liupeng,240)