Just curious, what's the thinking behind requiring transactions for reads? Also, some documentation updates might be appropriate. For example:
http://api.neo4j.org/current/org/neo4j/graphdb/NotInTransactionException.html public class NotInTransactionException extends RuntimeException <http://docs.oracle.com/javase/7/docs/api/java/lang/RuntimeException.html?is-external=true> Thrown when attempting to modify the graph outside of a transaction. Finally, I noticed that with 2.0, apparently the code wants you to use try/with, instead of try/finally, e.g. try ( Transaction tx = graphDb.beginTx() ) { blah(); } I'm also curious about that decision, since it requires I choose between looking at deprecation warnings on my use of tx.finish() or trying to upgrade all my developer's IDEs to java7 code style compliance. Thanks On Tuesday, December 31, 2013 10:07:08 AM UTC-5, Michael Hunger wrote: > > Hi > > Read operation on the database and nodes and relationships now require > transactions > > Probably most sensible to wrap the tx around the entry point to your > service layer. > > HTH > > Michael > > Sent from mobile device > > Am 31.12.2013 um 15:53 schrieb "M. David Allen" > <allen....@gmail.com<javascript:> > >: > > I'm in the middle of retrofitting neo4j code that was running on 1.9.3 to > 2.0.0. This is all happening under windows, jdk1.7.0_45, and eclipse. > > I expected some teething problems and cut-overs; here's one I've run into: > > org.neo4j.graphdb.NotInTransactionException > at > org.neo4j.kernel.impl.persistence.PersistenceManager.getResource(PersistenceManager.java:214) > at > org.neo4j.kernel.impl.persistence.PersistenceManager.currentKernelTransaction(PersistenceManager.java:84) > at > org.neo4j.kernel.impl.core.ThreadToStatementContextBridge.transaction(ThreadToStatementContextBridge.java:53) > at > org.neo4j.kernel.impl.core.ThreadToStatementContextBridge.instance(ThreadToStatementContextBridge.java:47) > at org.neo4j.kernel.impl.core.NodeProxy.hasProperty(NodeProxy.java:346) > at blah.blah.mypackage.MyStorage.isMyObjectNode(Neo4JStorage.java:219) > at > blah.blah.mypackage.MyFactory.newObject(Neo4JPLUSObjectFactory.java:190) > at blah.blah.mypackage.MyFactory.listWorkflows(Neo4JStorage.java:933) > > I can make it happy by wrapping the methods below in a transaction, but > I'm pretty sure that's not the right thing to do. > > Here's the relevant method: > > public static boolean isMyObjectNode(Node n) { > return n != null && n.hasProperty(PROP_PLUSOBJECT_ID) && > n.hasProperty(PROP_TYPE) && n.hasProperty(PROP_SUBTYPE); > } > > (Context: all of those PROP_TYPE, etc are all public static final String) > > The "newObject" method in my package is just creating one of my domain > objects out of a node. In order to do that, it needs to check which kind > of node it's dealing with. I'd rather not paste that code because it's > involved and includes many other subclasses that makes the rabbit hole > deeper. Suffice to say I'm sure that it's just creating my domain objects, > and not modifying anything in the graph. > > The "listWorkflows" method looks like this: > > public static List<MyWorkflow> listWorkflows(User user, int maxReturn) > throws MyException { > if(maxReturn <= 0 || maxReturn > 1000) maxReturn = 100; > > String query = "start n=node:node_auto_index(type=\"" + > MyWorkflow.TYPE_WORKFLOW + "\") " + > "where has(n.oid) " + > "return n " + > "limit " + maxReturn; > > Iterator<Node> ns = Neo4JStorage.execute(query).columnAs("n"); > ArrayList<MyWorkflow> wfs = new ArrayList<MyWorkflow>(); > > while(ns.hasNext()) { > MyObject o = MyFactory.newObject(ns.next()); > if(o.isWorkflow()) wfs.add((MyWorkflow)o); > else { > log.warning("Returned non-workflow " + o + " from workflow > query!"); > } > } > > return wfs; > } // End listWorkflows > > Indeed this code (and its caller) doesn't happen within a transaction, but > it shouldn't need to -- no modification is going on here. > > Lastly -- yes, I know about labels, and how labels would probably be a > better way to do this. I'm planning on exploiting that, but the first > thing to do is to get the current code base working on the new release, and > I've got other fish to fry (like cypher query syntax updates to get rid of > "?") before I get to using labels. > > Thanks! > > -- > 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 neo4j+un...@googlegroups.com <javascript:>. > For more options, visit https://groups.google.com/groups/opt_out. > > -- 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 neo4j+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
