Fetching all the paths between two nodes using gremlin in java

问题

Hi I am kinda new to gremlin and trying to achieve some solve by finding all the paths between two nodes. In simple query on gremlin console I was able to do that using this query :

(Name of the first Node).loop(1){it.loops<100}{true}.has('name', (Name of the second node)).path{it.name}

But while I was trying to fetch that from java methods I am into sea of problems, like:

-- no clue on where to put the query exactly ? -- what data structure will be right to receive the array of rows. -- how to collect the first node and second node from the graph.

Here I have tried to proceed with this, but no clue :

  Graph g = new OrientGraph(AppConstants.GRAPH_LOCATION);
         List<String> vertexList = new ArrayList<String>();
         try{
             for (Vertex v : g.getVertices()) {
                    String vertexName = v.getProperty("name");
                    vertexList.add(vertexName);
                }    
             return vertexList;
         } catch (final Exception ex) {
             throw new AppSystemException(ex);
         }finally{
             g.shutdown();

Thanks, Sagir

回答1:

Your query doesn't make much sense to me, but the description helps. Here's an example, using TinkerGraph, to find all paths between marko and lop:

final Graph g = TinkerGraphFactory.createTinkerGraph();
List<List> names = new ArrayList<>();
new GremlinPipeline<Vertex, ArrayList<Vertex>>(g).V().has("name", "marko").as("x").out().loop("x",
        new PipeFunction<LoopPipe.LoopBundle<Vertex>, Boolean>() {
            @Override
            public Boolean compute(LoopPipe.LoopBundle<Vertex> loopBundle) {
                return loopBundle.getLoops() < 100;
            }
        }, new PipeFunction<LoopPipe.LoopBundle<Vertex>, Boolean>() {
            @Override
            public Boolean compute(LoopPipe.LoopBundle<Vertex> loopBundle) {
                return "lop".equals(loopBundle.getObject().getProperty("name"));
            }
        }
).has("name", "lop").path(new PipeFunction<Vertex, String>() {
    @Override
    public String compute(final Vertex vertex) {
        return vertex.getProperty("name");
    }
}).fill(names);

The names list will then be filled with the following 2 entries: