如何使用Spark Graphx打印出最短路径

import org.apache.spark.graphx._
import org.apache.spark.rdd.RDD

val vertices: RDD[(VertexId, String)] = sc.parallelize(Array((1L, "A"), (2L, "B"), (3L, "C"), (4L, "D"), (5L, "E")))
val edges: RDD[Edge[Double]] = sc.parallelize(Array(Edge(1L, 2L, 1.0), Edge(2L, 3L, 2.0), Edge(3L, 4L, 3.0), Edge(4L, 5L, 4.0), Edge(1L, 5L, 10.0)))
val graph: Graph[String, Double] = Graph(vertices, edges)

val sourceId: VertexId = 1L
val shortestPaths: Graph[SPMap, Double] = graph.shortestPaths(landmarks = Seq(sourceId))

val shortestPathsRDD: RDD[(VertexId, Map[VertexId, Double])] = shortestPaths.vertices.map { case (vertexId, spMap) => (vertexId, spMap) }
shortestPathsRDD.collect().foreach { case (vertexId, spMap) =>
  println(s"最短路径从节点 $sourceId 到节点 $vertexId 的距离为:")
  spMap.foreach { case (targetId, distance) =>
    println(s"  - 经过节点 $targetId，距离为 $distance")
  }
}