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

[Samppa S. <sam...@pr...>]

In addition to getObject returning RDFNodes via a configurable factory 
we could provide pseudo columns to access properties of nodes (type, 
datatype, lang) e.g.

ResultsSet rs = executeQuery("select * where {?s ?p ?o}");
while (rs.next()) {
    String label = rs.getString("o");
    int type = rs.getInt("o$type");
    switch (type) {
        case RESOURCE: ...
        case BLANK_NODE: ...
        case PLAIN_LITERAL:
           String lang = rs.getString("o$lang");
           ...
        case TYPED_LITERAL:
           String datatype = rs.getString("o$datatype");
           ...
    }
}

Should XMLLiteral be handled as a separate type or as a typed literal 
with datatype rdf:XMLLiteral?

Br,
  Samppa

> Hello.
>
> Concerning SELECT results access it would be possible to plug RDF apis 
> into the driver via a factory interface.
>
> We could provide a neutral SPARQL4J dependent minimal RDF API and in 
> addition to this the possibility to plug external APIs into the driver.
>
> RDF nodes (or any other objects returned by the factory) could be 
> accessed via the umtyped accessors of the JDBC result set.
>
> e.g.
>
> interface NodeFactory{
>
>  public Object createLiteral(String lex, String lang, String datatype);
>
>  public Object createResource(String uri);
>
>  public Object createResource(String ns, String local);
>
>  public Object createBlankNode(String internalID);
>
> }
>
> The name of the implementation class could be given to the Driver via 
> the property map.
>
> Br,
> Timo.
>


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Samppa Saarela <samppa.saarela at profium.com> Profium, Lars Sonckin kaari 12, 02600 Espoo, Finland Tel. +358 (0)9 855 98 000 Fax. +358 (0)9 855 98 002 Mob. +358 (0)41 515 1412  Internet: http://www.profium.com