1.样例类实现自定义排序,需要实现ordered特质,不需要实现serializable,不需要new对象(本文样例类)
2.普通类实现自定义排序,需要实现ordered特质,实现serializable
姓名name 年龄age 颜值fv
文本为(Array(“mimi1 22 85”, “mimi2 22 86”, “mimi3 23 86”))
按照颜值降序、年龄降序排列
import org.apache.spark.rdd.RDD
import org.apache.spark.{
SparkConf, SparkContext}
object CustomSort_2 {
def main(args: Array[String]): Unit = {
val conf = new SparkConf()
conf.setAppName(this.getClass.getName).setMaster("local[2]")
val sc = new SparkContext(conf)
val userInfo: RDD[String]
= sc.parallelize(Array("mimi1 22 85", "mimi2 22 86", "mimi3 23 86"))
//对文本进行拆分,并返回一个元组
val personRDD: RDD[(String, Int, Int)] = userInfo.map(x => {
val arr = x.split(" ")
val name = arr(0)
val age = arr(1).toInt
val fv = arr(2).toInt
(name, age, fv)
})
//指定排序规则,把元组的字段传入person2中,按照person2的compare方法进行排序
val sorted: RDD[(String, Int, Int)] = personRDD.sortBy(x => person2(x._1, x._2, x._3))
println(sorted.collect.toBuffer)
}
}
case class person2(val name:String,val age:Int, val fv:Int) extends Ordered[person2]{
override def compare(that: person2): Int = {
if(this.fv!=that.fv)
that.fv- this.fv
else that.age - this.age
}
override def toString: String = s"$name,$age,$fv"
}
运行结果
ArrayBuffer((mimi3,23,86), (mimi2,22,86), (mimi1,22,85))