CODEWITHSUNDEEP
titan
srujana
srujana

Reputation: 182

How to add properties for TitanVertext in titan graph 1.0.0

I am using titan 1.0.0-hadoop1. I am trying to add some list of properties to Vertex that i am creating. In earlier versions such as 0.5.4 you can add property directly with setProperty, but in latest API i find it difficult to add property. I could not even find right solution in the internet.

Please help me in adding the properties to Vertex in Titan Java API.

Upvotes: 1

Views: 728

Answers (2)

OctopusSD
OctopusSD

Reputation: 90

I am also using titan 1.0.0 graph database with cassandra storage backend and has the same problem after upgrading from 0.5.4 version. I found simple generic solution to add any Collection object (Set or List) to the vertex property using this method. 

public static void setMultiElementProperties(TitanElement element, String key, Collection collection) {
    if (element != null && key != null && collection != null) {
        // Put item from collection to the property of type Cardinality.LIST or Cardinality.SET
        for (Object item : collection) {
            if (item != null)
                element.property(key, item);
        }
    }
}

Same method implementation with Java 8 syntacs:

public static void setMultiElementProperties(TitanElement element, String key, Collection collection) {
    if (element != null && key != null && collection != null) {
        // Put item from collection to the property of type Cardinality.LIST or Cardinality.SET
        collection.stream().filter(item -> item != null).forEach(item -> element.property(key, item));
    }
}

TitanElement object is the parent of TitanVertex and TitanEdge objects so you can pass vertex or edge to this method. Of course you need to declare element property first with Cardinality.Set or Cardinality.List using TitanManagement to use the multi value property.

TitanManagement tm = tittanGraph.openManagement();
tm.makePropertyKey(key).cardinality(Cardinality.LIST).make();// or Cardinality.SET
tm.commit();

To retrieve the collection from element property you can simple use:

Iterator<Object> collectionIter = element.values(key);

And this is Java 8 way to iterate over it:

List<Object> myList = new ArrayList<>();
collectionIter.forEachRemaining(item -> myList.add(item));

Upvotes: 0

Filipe Teixeira
Filipe Teixeira

Reputation: 3565

An example will help:

Vertex vertex = graph.addVertex();
vertex.property("ID", "123"); //Creates ID property with value 123

creates the property. To query the property:

vertex.property("ID"); //Returns the property object
vertex.value("ID");    //Returns "123"
vertex.values();       //Returns all the values of all the properties

When you having difficulty understanding the Titan API. I recommend looking at the TinkerPop API. Titan implements it so all tinkerpop commands work with titan graphs.

Upvotes: 1

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