Spark经典案例6-求top值

来源：互联网发布：上海美团数据分析编辑：程序博客网时间：2024/05/22 04:50

需求分析
orderid,userid,payment,productid
求topN的payment值
a.txt
1,9819,100,121
2,8918,2000,111
3,2813,1234,22
4,9100,10,1101
5,3210,490,111
6,1298,28,1211
7,1010,281,90
8,1818,9000,20

b.txt
100,3333,10,100
101,9321,1000,293
102,3881,701,20
103,6791,910,30
104,8888,11,39

scala代码

package ClassicCaseimport org.apache.spark.{SparkConf, SparkContext}/**  * 业务场景：求top值  * Created by YJ on 2017/2/8.  */object case6 {  def main(args: Array[String]): Unit = {    val conf = new SparkConf().setMaster("local").setAppName("reduce")    val sc = new SparkContext(conf)    sc.setLogLevel("ERROR")    val six = sc.textFile("hdfs://192.168.109.130:8020//user/flume/ClassicCase/case6/*", 2)    var idx = 0;    val res = six.filter(x => (x.trim().length > 0) && (x.split(",").length == 4))      .map(_.split(",")(2))      .map(x => (x.toInt, ""))      .sortByKey(false)    //fasle ->倒序      .map(x => x._1).take(5)      .foreach(x => {        idx = idx + 1        println(idx + "\t" + x)      })  }}

结果输出:
1 9000
2 2000
3 1234
4 1000
5 910

0 0