Hi! Did you initialize the db field?
Something like db = new GraphDatabaseFactory().newEmbeddedDatabase( "path/to/db" ); /anders On Thu, Apr 17, 2014 at 9:11 AM, Tingting Cui <[email protected]> wrote: > when i try to run TraversalExample.java example and create the graph like > this > it give me error like this > Exception in thread "main" java.lang.NullPointerException > at setupneo4j.TraversalExample.<init>(TraversalExample.java:23) > at setupneo4j.TraversalExample.main(TraversalExample.java:33) > what is the problems here. > public static void main( String[] args ) > { > > TraversalExample op = new TraversalExample( db ); > op.shutdownGraph(); > } > public void shutdownGraph() > { > try > { > if ( db != null ) > { > db.shutdown(); > } > } > finally > { > db = null; > } > } > > public Node createTheGraph() > { > try ( Transaction tx = db.beginTx() ) > { > // START SNIPPET: createGraph > Node A = db.createNode(); > Node B = db.createNode(); > Node C = db.createNode(); > Node D = db.createNode(); > > A.createRelationshipTo( C, Rels.KNOWS ); > C.createRelationshipTo( D, Rels.KNOWS ); > A.createRelationshipTo( B, Rels.KNOWS); > B.createRelationshipTo( C, Rels.KNOWS ); > // END SNIPPET: createGraph > A.setProperty( "name", "A" ); > B.setProperty( "name", "B" ); > C.setProperty( "name", "C" ); > D.setProperty( "name", "D" ); > tx.success(); > return A; > } > } > > -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- Anders Nawroth [[email protected]] Skype: anders.nawroth -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
