Index<Node> spatialindex;

 if(!index.existsForNodes("layer1"))
        {
            spatialindex = index.forNodes("layer1",SpatialIndexProvider.SIMPLE_POINT_CONFIG);            

        }
        else
        {
            spatialindex=index.forNodes("layer1");
        }

The snippet of addition

Node v = this.bgr.gds.createNode(); //creation
v.setProperty("lat", pkg.latitude);
v.setProperty("lon", pkg.longitude);
this.spatialindex.add(v,"dummy","value");

The snippet for searching

public Iterator<Node> queryPackagesSpatial(BiopolisSpatialQuery sq)
    {
        HashMap<String, Object> params = new HashMap<String, Object>();
        params.put(LayerNodeIndex.POINT_PARAMETER, new Double[]{sq.longitude,sq.latitude} );
        params.put(LayerNodeIndex.DISTANCE_IN_KM_PARAMETER, sq.radius);
        return this.bgr.pkg_mgmnt.spatialindex.query(LayerNodeIndex.WITHIN_DISTANCE_QUERY,params);
    }