spark--transform算子--join

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

/**
* Created by liupeng on 2017/6/16.
*/
object T_join {
System.setProperty("hadoop.home.dir","F:\\hadoop-2.6.5")

def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("join_test").setMaster("local")
val sc = new SparkContext(conf)

val rdd = sc.parallelize(List(("A",1), ("B", 2), ("C", 3)))
val rdd1 = sc.parallelize(List(("A", 4)))
val rdd2 = sc.parallelize(List(("A", 4), ("A", 5)))
//join方法为(K,V)和(K,W)的数据集调用，返回相同的K所组成的数据集
val sum = rdd.join(rdd1)
.foreach(println)
val sum1 = rdd.join(rdd2)
.foreach(println)
}
}