HDT with Fuseki 3.4.0

[Dominique Vandensteen <do...@cogni.zone>]

Hi,
I tried running HDT (
http://www.rdfhdt.org/manual-of-hdt-integration-with-jena/) on my fuseki
3.4.0 server. When doing a query, I get a NoClassDefFoundError
for org.apache.jena.sparql.core.DatasetGraphMaker
I saw that this class existed till v3.0.1 and got deleted in this commit
https://github.com/apache/jena/commit/603fccfec03f0836c73ff302c5c4dc6c9c17c7d3
I re-created the class and added it to my server which seems to work fine
for now.
Is there any chance the class can be put back in a new version?

Thanks,
Domi

Re: HDT with Fuseki 3.4.0

[Andy Seaborne <an...@apache.org>]

Hi Domi,

HDT depends on Jena 3.0.1 (8-Dec-2015). There will be other changes so 
fixing one class and using later version of Jena is not guaranteed to work.

Surely, it's not just putting back one class - it's switching back to 
using that class as used by Jena's RDFDataset assembler etc etc.

It would be better if hdt-java updated the dependency of Jena.
   https://github.com/rdfhdt/hdt-java/issues/44

There is hdt-java/pull/47 which updates to Apache Jena 3.2.0
and stops using DatasetGraphMaker.

But the use in HDT OptimizedCount (the only use I found) looks to be 
doing unnecessary casting anyway: why not:

Graph g = (graphName==null)
	?dataset.getDefaultGraph()
	:dataset.getGraph(graphName);

no casting.

On 17/11/17 12:15, Dominique Vandensteen wrote:
> Hi,
> I tried running HDT (
> http://www.rdfhdt.org/manual-of-hdt-integration-with-jena/) on my fuseki
> 3.4.0 server. 

FYI: hdt:DatasetHDT rdfs:subClassOf ja:RDFDataset .

isn't used so can be removed.

in HDTGraphAssembler:
static {
	init();
}

can be replaced by using Jena's initialization sequence:
http://jena.apache.org/documentation/notes/system-initialization.html

Then no need for
    ja:loadClass "org.rdfhdt.hdtjena.HDTGraphAssembler" .

> When doing a query, I get a NoClassDefFoundError
> for org.apache.jena.sparql.core.DatasetGraphMaker
> I saw that this class existed till v3.0.1 and got deleted in this commit
> https://github.com/apache/jena/commit/603fccfec03f0836c73ff302c5c4dc6c9c17c7d3
> I re-created the class and added it to my server which seems to work fine
> for now.
> Is there any chance the class can be put back in a new version?
> 
> Thanks,
> Domi
>