如何使用Spark Graphx或Graphframe创建有向图

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

val vertexRDD: RDD[(VertexId, String)] = sc.parallelize(Array(
  (1L, "Alice"),
  (2L, "Bob"),
  (3L, "Charlie"),
  (4L, "David")
))

val edgeRDD: RDD[Edge[String]] = sc.parallelize(Array(
  Edge(1L, 2L, "friend"),
  Edge(2L, 3L, "follow"),
  Edge(3L, 1L, "like"),
  Edge(4L, 1L, "comment")
))

val graph: Graph[String, String] = Graph(vertexRDD, edgeRDD)

val degrees: VertexRDD[Int] = graph.degrees
val neighbors: VertexRDD[Array[(VertexId, String)]] = graph.collectNeighborIds(EdgeDirection.Out)

import org.graphframes._

val vertexDF = spark.createDataFrame(Seq(
  (1L, "Alice"),
  (2L, "Bob"),
  (3L, "Charlie"),
  (4L, "David")
)).toDF("id", "name")

val edgeDF = spark.createDataFrame(Seq(
  (1L, 2L, "friend"),
  (2L, 3L, "follow"),
  (3L, 1L, "like"),
  (4L, 1L, "comment")
)).toDF("src", "dst", "relationship")

val graph = GraphFrame(vertexDF, edgeDF)

val degrees = graph.degrees
val neighbors = graph.collectNeighborIds(EdgeDirection.Out)