On 28/09/13 23:46, Andreas Grünwald wrote:
Hello,
I am trying to implement proper transaction handling based on the latest
Jena TDB version.
This is how I roughly initialize the model entities (I work with Jena's
OntModel):
class ConnectorWrapper
public void init() {
Dataset tdbDataSet = TDBFactory.createDataset(directory);
model = tdbDataSet.getNamedModel(this.getOntologySchemaIRI());
this.ontModel = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM,
model);
}
}
I ran into some problems.
1. tdbDataSet.abort() is not working for me. As far as I got from the
documentation, the OwlModel does not support transactions. Did I got that
correct? Is there any kind of workaround?
Perform the transaction on the tdbDataSet.
Get the model inside the dataset.
2. How do I properly close/destroy a Jena Dataset? I am running into the
situation that I have several "Connector" instances (within one Thread),
which wrap an instance of the Jena Dataset. However, only the first
initialization succeeds, for the latter I get something like "transaction
is not active". I also get some errors in the command line "ERROR
com.hp.hpl.jena.tdb.transaction.BlockMgrJournal - **** Not active: 1"
although I call "tdbDataSet.close() and tdbDataSet.end()" before calling
init() again. Is TDBFactory.createDataset(directory) the correct way to
retrieve a dataset-instance, or should I call another method? Does my
initialization approach seem ok?
Yes - use TDBFactory.createDataset(directory), or have a single variable
for the object and initialize once.
Don't bother closing it - when transactional, close is meaningless (and
harmless).
Note that one thread can only have one transaction active.
If that is not working, please could you provide a complete, minimal
example as the details matter here.
Andy
Thank you very much and best regards,
Andreas
