In Apache Tinkerpop Gremlin load csv file(text file)? - gremlin

Question

I am using the following script in gremlin to create a graph by using CSV file (text file):
code:
g = TinkerGraph.open()
vs=[ ] as Set
new File("edges.txt").eachLine{l->p=l.split("\t");vs<<p[0];vs<<p1;}
vs.each{v->g.addVertex(v)}
new File("edges.txt").eachLine{l->p=l.split("\t");g.addEdge(g.getVertex(p[0]),g.getVertex(p1),"friend")}
g.E
When the above code is applied these errors occur:
No signature of method: org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerGraph.getVertex() is applicable for argument types: (String) values: 1
Possible solutions: addVertex([Ljava.lang.Object;), getAt(java.lang.String)
Note that csv file("edges.txt") is like this:
Source Destination
2 4
3 5
2 8

Answer 1

I changed your code to use the Traversal API, as there is no addEdge method exported by TinkerGraph (addEdge is actually a method of the Vertex class). In general using the Traversal API is the way to go for application code. The Graph API is more for backend developers these days (database providers).
g = TinkerGraph.open().traversal()
vs=[ ] as Set
new File(edges.txt").eachLine{l->p=l.split(",");vs<<p[0];vs<<p1;}
vs.each{v->g.addV().property(T.id,v).next()}
new File("edges.txt").eachLine{l->p=l.split(",");g.addE("friend").from(V(p[0])).to(V(p[1])).next()}
I ran this in the gremlin console and after all the steps above have been run, we can see the graph has been created. Note I changed the separator to be a comma, just as it was easier to type when I was creating the test file.
gremlin> g.E()
==>e[0][2-friend->4]
==>e[1][3-friend->5]
==>e[2][2-friend->8]