EdgeTriplet Class

An edge triplet represents an edge along with the vertex attributes of its neighboring vertices.

VD: the type of the vertex attribute.

ED: the type of the edge attribute

instance constructor:

new EdgeTriplet()

var attr: ED
The attribute associated with the edge

var dstAttr: VD
The destination vertex attribute

var dstId: VertexId
The vertex id of the target vertex

def otherVertexAttr(vid: VertexId): VD
Given one vertex in the edge return the other vertex.

def otherVertexId(vid: VertexId): VertexId
Given one vertex in the edge return the other vertex.

def relativeDirection(vid: VertexId): EdgeDirection
Return the relative direction of the edge to the corresponding vertex.

var srcAttr: VD
The source vertex attribute

var srcId: VertexId
The vertex id of the source vertex

def toString(): String
def
toTuple: ((VertexId, VD), (VertexId, VD), ED)

def vertexAttr(vid: VertexId): VD
Get the vertex object for the given vertex in the edge

Example:

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

// Create an RDD for the vertices
val users: RDD[(VertexId, (String, String))] =
  sc.parallelize(Array((3L, ("rxin", "student")), (7L, ("jgonzal", "postdoc")),
                       (5L, ("franklin", "prof")), (2L, ("istoica", "prof")),
                       (4L, ("peter", "student"))))
// Create an RDD for edges
val relationships: RDD[Edge[String]] =
  sc.parallelize(Array(Edge(3L, 7L, "collab"),    Edge(5L, 3L, "advisor"),
                       Edge(2L, 5L, "colleague"), Edge(5L, 7L, "pi"),
                       Edge(4L, 0L, "student"),   Edge(5L, 0L, "colleague")))
// Define a default user in case there are relationship with missing user
val defaultUser = ("John Doe", "Missing")

graph.triplets.getClass
/*
res233: Class[_ <: org.apache.spark.rdd.RDD[org.apache.spark.graphx.EdgeTriplet[(String, String),String]]] = class org.apache.spark.rdd.MapPartitionsRDD
graph.triplets is an instance of EdgeTriplet

*/

// Build the initial Graph
val facts: RDD[String] =
  graph.triplets.map((triplet =>
    triplet.srcAttr._1 + " is the " + triplet.attr + " of " + triplet.dstAttr._1))
facts.collect.foreach(println(_))

Reference:

https://github.com/apache/spark/blob/v2.4.5/graphx/src/main/scala/org/apache/spark/graphx/EdgeTriplet.scala