利用case class将RDD转化为DataFrame_rdd case class 转dataframe-优快云博客

本文介绍如何使用Apache Spark将文本文件加载为RDD，并通过case class定义模式将其转换为DataFrame的过程。涉及Spark基本配置、日志级别设置、SparkSession创建、文本文件读取、RDD模式定义及转换等关键技术点。

先定义一个case clas

case class people(id:Int, name:String, age:Int)

读取txt，转化为RDD

val rddpeople = sc.textFile("source path")

利用case class给RDD一个schema

val peopleSchema = rddpeople.map(row => row.split(" ")).map(field => people(field(0).toInt,field(1),field(2).toInt))

将RDD转为Dataframe

val peopleDf = peopleSchema.toDF()

完整代码：

import org.apache.spark.{SparkConf, SparkContext}
import org.apache.log4j._
import org.apache.spark.sql.SparkSession


case class people (id:Int,name:String,age:Int)

object test {
  def main(args: Array[String]): Unit = {
    Logger.getLogger("org").setLevel({Level.ERROR})

    val conf = new SparkConf().setAppName("Interview").setMaster("local")
    val sc = new SparkContext(conf)
    val spark = SparkSession.builder().appName("test").getOrCreate()
    import spark.implicits._

    val rddpeople = sc.textFile("src/test/people.txt")
    val peopleSchema = rddpeople.map(row => row.split(" ")).map(field => people(field(0).toInt,field(1),field(2).toInt))
    val peopleDf = peopleSchema.toDF()
    peopleDf.show()
  }
}