On 06/01/2020 11:15, Ashwani Rathi wrote:
Thanks for the information Andy.
Currently we are using jena-2.8.8
Can you also please share some documentation on how can we use Fuseki with TDB
and interface RDFConnection?
https://jena.apache.org/documentation/rdfconnection/
https://jena.apache.org/documentation/tdb/
https://jena.apache.org/documentation/tdb2/
Regards,
Ashwani
On 06/01/20, 4:29 PM, "Andy Seaborne" <[email protected]> wrote:
On 06/01/2020 05:50, Ashwani Rathi wrote:
> Hi All,
> We have the following method where we are using Jena 2
Which version of jena 2 exactly?
, where we are trying to fetch/ create Model object from ModelRDB
utility method using com.hp.hpl.jena.db.IDBConnection
> private Model getModelFromRDFStore(String modelName, IDBConnection conn)
> {
> Model model = null;
> if (!conn.containsModel(modelName)) {
> model = ModelRDB.createModel(conn, modelName);
> }
> else {
> model = ModelRDB.open(conn, modelName);
> }
>
> return model;
> }
>
> com.hp.hpl.jena.db.IDBConnection basically encapsulates a JDBC connection.
>
> Now support for com.hp.hpl.jena.db.IDBConnection and corresponding implementing classes has been removed from Jena 3.
> This is the functionality which we are trying to replicate in Jena 3.
See prvious reply - it depends on what the application is trying to do,
and what sort fo reliability of data it requires.
For just a local data base, use TDB.
Note: all storage in jena3 is based on "Datasets", not "Models". Use the
default model of a dataset for a single RDF graph in a database.
For a database on a remote server shared between several instances of
your application, use Fuseki with TDB and interface RDFConnection.
>
> So can you please guide how can we achieve this functionality in Jena 3 using TDB or something else?
Dataset dataset = TDB2Factory.connectDataset("some directory");
dataset.getDefaultModel();
but also all access to the database needs to be in a dataset transaction
See Txn and the documentation
https://urldefense.proofpoint.com/v2/url?u=https-3A__jena.apache.org_documentation_txn_&d=DwIDaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=ld8gXdwUlVansMT0flGoGNN0AOkhQba_hAJM5PewJCA&m=CThVIE5cplymnNcjUUNuq_4CFBNj8BUjRg3PWigMKAE&s=lEE_JneU-vmNLseoh-8pF4OwY1uoaD2EZetxHezQnSs&e=
Andy
>
> Regards,
> Ashwani
>
> On 06/01/20, 3:55 AM, "Andy Seaborne" <[email protected]> wrote:
>
>
>
> On 05/01/2020 09:15, Ashwani Rathi wrote:
> > Hi,
> >
> > We are upgrading from jena 2 to jena 3 in our project.
> >
> > While jena used to have the following two classes in jena.jar:
> > com.hp.hpl.jena.db.DBConnection
> > com.hp.hpl.jena.db.IDBConnection
>
> That is the very old RDB layer; I am no sure it was ever released as
> Apache Jena release. Which version of Jena do you have? 2.6.4 or earlier?
>
> > there are no such classes in jena 3
>
> There have been a lot of changes, including going from RDF 1.0 to RDF 1.1.
>
> > We are using these classes in our project.
> >
> > Can someone guide me or provide a prototype on what claaes in jena 3 can be used to provide functionality for these missing classes?
>
> The current persistent storage options are TDB (TDB1, and TDB2). These
> are custom RDF storage systems. They scale better, load faster, run
> faster and are more robust than RDB. There is a SQL-backed storage
> system as well but we don't recommend it for any new work - and it is
> not compatible in any way with RDB.
>
> But if, as I suspect, this is a big version jump, maybe the place to
> start is describing what use of RDF is made by your project? Is it
> using the Model API? Some early SPARQL?
>
> Andy
>
> > Regards,
> >
> > Ashwani
> >
> >
>
>
>
