SortBy

package com.shujia.spark.core

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

object Demo10Sort {
  def main(args: Array[String]): Unit = {

    val conf: SparkConf = new SparkConf()
      .setAppName("map")
      .setMaster("local")

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

    val listRDD: RDD[Int] = sc.parallelize(List(1, 2, 123, 3, 4, 23, 5, 6, 7, 8))

    /**
      * sortBy: 指定一个排序的列，默认是升序
      */

    val sortRDD: RDD[Int] = listRDD.sortBy(i => i, false)

    sortRDD.foreach(println)

    val kvRDD: RDD[(String, Int)] = sc.parallelize(List(("java", 100), ("spark", 20), ("hadoop", 12321)))

    /**
      * sortByKey: 通过key进行排序
      *
      */
    val sortByKeyRDD: RDD[(String, Int)] = kvRDD.sortByKey()

    sortByKeyRDD.foreach(println)
  }
}