adding non-http services to Fuseki

["Nouwt, B. (Barry)" <ba...@tno.nl.INVALID>]

Hi all,

we are using Apache Jena Fuseki 3.13 and would like to add a custom publish/subscribe service (next to the default SPARQL service). We are wondering whether this is possible within the provided framework of Operations/Processors/Actions, etc, since the Fuseki classes in the org.apache.jena.fuseki.servlets package like HttpAction and ServletBase seem to only support HTTP based services.

Thanks in advance!

Regards, Barry
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Re: adding non-http services to Fuseki

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

Hi Barry,

The FusekiServer.Builder (main) or web/xml (Fuseki full) can includes 
arbitrary servlets and servlet filters so anything can be added but the 
naming requirement may currently get in the way.

Routing is by the dataset part fo the URL path. If you want 
"/ds/myPubSub" and also /ds/sparql" then currently "myPubSub" will need 
to be an ActionProcessor (and will get the logging and counters added.)

Could you give a concrete description of the pub/sub? Which protocol(s) 
does it want to use if not HTTP? Plain TCP on differnt ports?

I don't think it is fundamental - changing it so failing to find a 
registered ActionProcessor could make the dispatcher drop through to 
normal servlet dispatch in Jetty (and 404 that way).

Or a ActionProcessor that refuses HTTP requests with 404 and does it's 
own TCP thing.

What parts of the Fuseki infrastructure would you want to access and reuse?

     Andy

On 12/12/2019 08:41, Nouwt, B. (Barry) wrote:
> Hi all,
> 
> we are using Apache Jena Fuseki 3.13 and would like to add a custom publish/subscribe service (next to the default SPARQL service). We are wondering whether this is possible within the provided framework of Operations/Processors/Actions, etc, since the Fuseki classes in the org.apache.jena.fuseki.servlets package like HttpAction and ServletBase seem to only support HTTP based services.
> 
> Thanks in advance!
> 
> Regards, Barry