rdd 基本操作

package com.jason.example

import org.apache.spark.rdd.RDD

class RddTest extends SparkInstance {
  val sc = spark.sparkContext
  val rdd = sc.parallelize( to )
  val rdd2 = sc.parallelize( to )
  val pairRdd = rdd2.map(x => (x, x * ))

  def trans(): Unit = {
    printRdd(rdd.filter(x => x %  == )) //2,4,6,8,10,12,14,16,18,20
    printRdd(rdd.map(x =>  to x)) //Range(1),Range(1, 2),Range(1, 2, 3),Range(1, 2, 3, 4),Range(1, 2, 3, 4, 5),Range(1, 2, 3, 4, 5, 6),Range(1, 2, 3, 4, 5, 6, 7),Range(1, 2, 3, 4, 5, 6, 7, 8),Range(1, 2, 3, 4, 5, 6, 7, 8, 9),Range(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
    printRdd(rdd.flatMap(x =>  to x)) //1,1,2,1,2,3,1,2,3,4
    printRdd(rdd.mapPartitions { it => it.map(_ + 0.5) }) //1.5,2.5,3.5,4.5,5.5,6.5,7.5,8.5,9.5,10.5
    printRdd(rdd.mapPartitionsWithIndex((x, i) => i.map(_ + 0.5))) //1.5,2.5,3.5,4.5,5.5,6.5,7.5,8.5,9.5,10.5
    printRdd(rdd.sample(true, 0.2)) //
    printRdd(rdd2.union(rdd)) //9,10,11,12,13,14,15,1,2,3
    printRdd(rdd.intersection(rdd2)) //9,10
    printRdd(rdd.distinct()) //4,8,1,9,5,6,10,2,3,7
    rdd.coalesce()
    rdd.repartition()
    rdd.groupBy(x => x)
    //pairRdd
    printRdd(pairRdd.groupBy(x => x._2)) //(28,CompactBuffer((14,28))),(24,CompactBuffer((12,24))),(20,CompactBuffer((10,20))),(22,CompactBuffer((11,22))),(30,CompactBuffer((15,30))),(18,CompactBuffer((9,18))),(26,CompactBuffer((13,26)))
    printRdd(pairRdd.groupByKey()) //(12,CompactBuffer(24)),(13,CompactBuffer(26)),(9,CompactBuffer(18)),(14,CompactBuffer(28)),(10,CompactBuffer(20)),(15,CompactBuffer(30)),(11,CompactBuffer(22))
    printRdd(pairRdd.reduceByKey(_ + _)) //(12,24),(13,26),(9,18),(14,28),(10,20),(15,30),(11,22)
    printRdd(pairRdd.aggregateByKey()((u, x) => u + x, (u1, u2) => u1 + u2)) //(12,24),(13,26),(9,18),(14,28),(10,20),(15,30),(11,22)
    printRdd(pairRdd.sortByKey(false)) //(15,30),(14,28),(13,26),(12,24),(11,22),(10,20),(9,18)
    printRdd(pairRdd.join(pairRdd)) //(12,(24,24)),(13,(26,26)),(9,(18,18)),(14,(28,28)),(10,(20,20)),(15,(30,30)),(11,(22,22))
    pairRdd.leftOuterJoin(pairRdd)
    pairRdd.rightOuterJoin(pairRdd)
    pairRdd.fullOuterJoin(pairRdd)

    printRdd(pairRdd.cogroup(pairRdd)) //(12,(CompactBuffer(24),CompactBuffer(24))),(13,(CompactBuffer(26),CompactBuffer(26))),(9,(CompactBuffer(18),CompactBuffer(18))),(14,(CompactBuffer(28),CompactBuffer(28))),(10,(CompactBuffer(20),CompactBuffer(20))),(15,(CompactBuffer(30),CompactBuffer(30))),(11,(CompactBuffer(22),CompactBuffer(22)))
    pairRdd.groupWith(pairRdd)
    printRdd(rdd.cartesian(rdd2)) //笛卡尔积 (1,9),(2,9),(1,10),(1,11),(2,10),(2,11),(1,12),(1,13),(2,12),(2,13)
    rdd.setName("haha")

    stop()
  }

  def actionTest(): Unit = {
    rdd.aggregate()((u, x) => x + u, (u1, u2) => u1 + u2)
    rdd.reduce(_ + _)
    rdd.count()
    rdd.first()
    rdd.take()
    rdd.takeOrdered()
    rdd.takeSample(true, )
    println(pairRdd.countByKey()) //Map(10 -> 1, 14 -> 1, 9 -> 1, 13 -> 1, 12 -> 1, 11 -> 1, 15 -> 1)
    println(pairRdd.countByValue()) //Map((10,20) -> 1, (9,18) -> 1, (11,22) -> 1, (14,28) -> 1, (13,26) -> 1, (12,24) -> 1, (15,30) -> 1)
    rdd.countByValue()
    println(rdd.countApprox())
    stop()
  }

  def printRdd[U](rdd: RDD[U]): Unit = {
    println(rdd.take().mkString(","))
  }
}

object RddTest {
  def main(args: Array[String]): Unit = {
    val rt = new RddTest
    rt.trans()
    rt.actionTest()

    //Runtime.getRuntime.exec(s"""C:\notos\code\jason-ml\jason""")
  }
}