如何从RDD[String]中创建特定字段的hashMap？

import org.apache.spark.rdd.RDD
import scala.collection.mutable.HashMap

val rdd: RDD[String] = ...

val keyValueRDD: RDD[(String, String)] = rdd.map(line => {
  val fields = line.split(",") // 假设字段之间使用逗号分隔
  (fields(0), fields(1)) // 假设要将第一个字段作为键，第二个字段作为值
})

val reducedRDD: RDD[(String, String)] = keyValueRDD.reduceByKey((value1, value2) => value1 + "," + value2)

val hashMap: HashMap[String, String] = HashMap(reducedRDD.collect(): _*)