user2524707 user2524707 - 8 days ago 5
Java Question

Titan receive edge which connects any nodes of two sets

I am trying to retrieve all edges which connect any of the nodes in set A and one of the nodes in set B.
Current approach:

ArrayList<Vertex> nodeStartList = getVertexList(relationshipStorage.getStartNode(), g, snapshotId);
ArrayList<Vertex> nodeEndList = getVertexList(relationshipStorage.getEndNode(), g, snapshotId);


The vertex lists are correctly filled (Already checked that)

GraphTraversal<Vertex, Edge> tempOutput = g.V(nodeStartList.toArray()).bothE().where(__.is(P.within(nodeEndList.toArray()))).hasLabel(relationshipStorage.getId());


But I always retrieve an empty list from output.
And I'm sure I have edges matching my query.

Answer

Here is something that works:

gremlin> graph = TinkerGraph.open();
==>tinkergraph[vertices:0 edges:0]
gremlin> v1 = graph.addVertex();
gremlin> v2 = graph.addVertex();
gremlin> v3 = graph.addVertex();
gremlin> v4 = graph.addVertex();
gremlin> v5 = graph.addVertex();
gremlin> v6 = graph.addVertex();
gremlin> v1.addEdge("edgeLabel", v4);
gremlin> v2.addEdge("edgeLabel", v5);
gremlin> v3.addEdge("edgeLabel", v6);

The above creates 6 vertices with 3 edges between them. I can then find those edges with:

gremlin> graph.traversal().V(v1, v2, v3).bothE().filter(otherV().is(within(v4, v5, v6)))
==>e[6][0-edgeLabel->3]
==>e[7][1-edgeLabel->4]
==>e[8][2-edgeLabel->5]
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