This problem has a simple solution: Remove neo4j-commons-1.0 from your classpath, it conflicts with the commons classes in 1.1-SNAPSHOT (that have now moved into kernel).
Cheers, Tobias On Wed, Jun 30, 2010 at 12:24 PM, Christian Morgner < [email protected]> wrote: > Hi all, > > I encountered a problem with the new TraversalDescription API in > 1.1-SNAPSHOT (1.1-20100628.145423-131), using neo4j-commons-1.0. > > The code > > TraversalDescription descr = TraversalFactory.createTraversalDescription() > > .breadthFirst() > .expand(TraversalFactory.expanderForType(RelTypes.HAS_CHILD, > Direction.OUTGOING)) > .filter(getPredicateForTest(nodeTest)) > ; > > > throws > > java.lang.InstantiationError: org.neo4j.commons.iterator.FilteringIterator > at > > org.neo4j.kernel.StandardExpander$RegularExpander.doExpand(StandardExpander.java:523) > at > > org.neo4j.kernel.StandardExpander$RelationsipExpansion.iterator(StandardExpander.java:145) > at > > org.neo4j.kernel.impl.traversal.ExpansionSourceImpl.expandRelationships(ExpansionSourceImpl.java:54) > at > > org.neo4j.kernel.impl.traversal.StartNodeExpansionSource.next(StartNodeExpansionSource.java:24) > at > > org.neo4j.kernel.PreorderBreadthFirstSelector.nextPosition(PreorderBreadthFirstSelector.java:29) > at > > org.neo4j.kernel.impl.traversal.TraverserImpl$TraverserIterator.fetchNextOrNull(TraverserImpl.java:139) > at > > org.neo4j.kernel.impl.traversal.TraverserImpl$TraverserIterator.fetchNextOrNull(TraverserImpl.java:75) > at > > org.neo4j.commons.iterator.PrefetchingIterator.hasNext(PrefetchingIterator.java:36) > at > org.neo4j.commons.iterator.IteratorWrapper.hasNext(IteratorWrapper.java:23) > > > on me when trying to iterate over the resulting Iterable<Node>, however > with a simple inline implementation of the RelationshipExpander > > TraversalDescription descr = TraversalFactory.createTraversalDescription() > > .breadthFirst() > > .expand(new RelationshipExpander() > { > public Iterable<Relationship> expand(Node node) > { > return(node.getRelationships(RelTypes.HAS_CHILD, > Direction.OUTGOING)); > } > > public RelationshipExpander reversed() > { > return(null); > } > } > ) > > .filter(getPredicateForTest(nodeTest)) > ; > > > it works. Maybe this is a problem with > TraversalFactory.expanderForTypes(RelationshipType t, Direction d), but > I can't figure it out.. Am I missing something here? What is the best > practice to create such a TraversalDescription? > > I also tried > > TraversalDescription descr = TraversalFactory.createTraversalDescription() > > .breadthFirst() > .relationships(RelTypes.HAS_CHILD, Direction.OUTGOING) > .filter(getPredicateForTest(nodeTest)) > ; > > > but got the same InstantiationError. > > Thanks, > Christian > > > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user > -- Tobias Ivarsson <[email protected]> Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
