RE: [Sparql4j-devel] Integration of external RDF APIs via Factory

[Seaborne, A. <and...@hp...>]

Hi Timo,



-------- Original Message --------
> From: Timo Westkamper <>
> Date: 22 December 2005 15:00
>=20
> Hello.
>=20
> Concerning SELECT results access it would be possible to plug RDF apis
> into the driver via a factory interface.=20

>=20
> We could provide a neutral SPARQL4J dependent minimal RDF API and in
> addition to this the possibility to plug external APIs into the
driver.=20

Sounds like a good idea.

Overall the interface looks OK - a few minor comments.

>=20
> RDF nodes (or any other objects returned by the factory) could be
> accessed via the umtyped accessors of the JDBC result set.=20
>=20
> e.g.
>=20
> interface NodeFactory{
>=20
>   public Object createLiteral(String lex, String lang, String
datatype);

Minor: as lang and datatype can't both be set:

createTypedLiteral(String lex, String datatype);
createPlainLiteral(String lex, String lang);

is possible.  As an internal factory API, it isn't significant - you're
one-call version is fine.

>=20
>   public Object createResource(String uri);
>=20
>   public Object createResource(String ns, String local);

Not sure about this one.  Namespaces are purely syntactic in RDF and the
XML Result format does not provide them.  Did you have a specific usage
in mind?

Wouldn't only an RDF/XML format results need this and then it is a
matter of a ful RDF parser anyway?

>=20
>   public Object createBlankNode(String internalID);
>=20
> }

One observation - RDF resources covers all graph labels (URI, blank
nodes and literals).  There isn't an official term for a URI labeled
node or arc so your naming is probably as good as it gets.

	Andy

>=20
> The name of the implementation class could be given to the Driver via
> the property map.=20
>=20
> Br,
> Timo.
>=20