Respected,
I created a graph and now i want to delete relationships in the graph based
on condition which is dependent of time.
I have allotted systemTime to each node and as well to each relationship
between nodes. So based on that I want to remove relationship between nodes
if they are older.
So for this, the code is looks
tx = myappdb.beginTx();
TraversalDescription td = null;
final long currentSystemTime = new Date().getTime();
System.out.printf("Current System time is %d \n",
currentSystemTime);
try{
td =
Traversal.description().breadthFirst().relationships(relType.Knows,
Direction.BOTH)
.uniqueness(Uniqueness.RELATIONSHIP_GLOBAL)
.evaluator(new Evaluator(){
public Evaluation evaluate(Path path) {
Node start = path.startNode();
Node end = path.endNode();
Relationship lastRel = path.lastRelationship();
if(lastRel == null){
return Evaluation.EXCLUDE_AND_CONTINUE;
}
long relTime = (Long)lastRel.getProperty("Timestamp");
if((currentSystemTime - ms) >= relTime){
for(Relationship rel :
start.getRelationships(relType.Knows, Direction.BOTH))
{
if (rel.getEndNode().equals(end)){
rel.delete();
}
}
if(!start.hasRelationship(relType.Knows)){
start.delete();
}else if(!end.hasRelationship(relType.Knows)){
end.delete();
}
return Evaluation.INCLUDE_AND_CONTINUE;
}else{
return Evaluation.INCLUDE_AND_CONTINUE;
}
}
});
for (Path path : td.traverse(referenceNode)){
Node testNode = (Node) path.endNode();
System.out.println("At Depth " +path.length() + " = " +
testNode.getProperty("Name"));
}
tx.success();
}catch(Exception ex){
ex.printStackTrace();
tx.failure();
}finally{
tx.finish();
}
.......
I don't know where I am doing mistake to solve the bug.
I am getting error "IllegalStateException" and I studied the about the error
and delete semantics of nodes and relationships.
But i tried in different different ways (method calling, without transation
commit, ......) to solve, but i couldn't solve. Can any one help me out from
this.
One more thing, is there any direct function to clean all nodes which don't
have relationships in the space. If so let me know....
Thanks for your time and awaiting for your valuable reply.
Regards,
G.
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