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Posted to users@jena.apache.org by Jason Koh <jb...@eng.ucsd.edu> on 2016/09/05 23:51:32 UTC
Fuseki REST API document?
Hi there,
I am Jason Koh, a PhD student at UCSD studying semantic web.
I am trying to use Jena+Fuseki as it supports REST API directly, but I
cannot find API documents for it. I was trying to do reverse-engineering,
but it is too much. *Is there any REST API document of Fuseki?*
Specific problem I currently face is following (in Python)
1) Working: requests.post('http://localhost:3030/myproject?query=SELECT
?anything WHERE{?anything ?aa ?bb} LIMIT 10')
2) Not working: requests.post('http://localhost:3030/myproject?query=
'prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> SELECT ?anything
WHERE{?anything rdf:type ?bb} LIMIT 10'')
This returns code 404, and the server says:
[2016-09-04 14:42:17] Fuseki INFO [12] 400 Parse error:
prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns
Encountered " "<" "< "" at line 1, column 13.
Was expecting:
<IRIref> ...
(5 ms)
I cannot help myself to debug this as I put one < for prefix which seems to
be standard in SPARQL.
*Does any of you know how to fix this problem?* (Still I would be very
happy to have an API doc.)
Thanks for all the open sources and supports. It really helps me.
With regards,
Jason Koh
cseweb.ucsd.edu/~jbkoh
Re: Fuseki REST API document?
Posted by Jason Koh <jb...@eng.ucsd.edu>.
Dear all and Andy,
Thanks for the answer. The HTTP encoding should have been considered as you
said! Thanks a lot. I ended up with using SPARQLWrapper (
https://rdflib.github.io/sparqlwrapper/) in Python as rdflib.prepareQuery
seems to be fixed to rdflib only (not Jena.)
Thanks again.
With regards,
Jason Koh
cseweb.ucsd.edu/~jbkoh
On Tue, Sep 6, 2016 at 1:06 AM, Andy Seaborne <an...@apache.org> wrote:
>
>
> On 06/09/16 00:51, Jason Koh wrote:
>
>> Hi there,
>>
>> I am Jason Koh, a PhD student at UCSD studying semantic web.
>>
>> I am trying to use Jena+Fuseki as it supports REST API directly, but I
>> cannot find API documents for it. I was trying to do reverse-engineering,
>> but it is too much. *Is there any REST API document of Fuseki?*
>>
>
> See the SPARQL protocol specification and SPARQL Graph Store Protocol.
>
> Links at the top of:
> http://jena.apache.org/documentation/fuseki2/
>
> Specific problem I currently face is following (in Python)
>>
>> 1) Working: requests.post('http://localhost:3030/myproject?query=SELECT
>> ?anything WHERE{?anything ?aa ?bb} LIMIT 10')
>>
>> 2) Not working: requests.post('http://localhost:3030/myproject?query=
>> 'prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> SELECT
>> ?anything
>> WHERE{?anything rdf:type ?bb} LIMIT 10'')
>>
>
> This is not a SPARQL problem.
>
> The URL has a # in it - that's the start of a URL fragment and it is not
> part of the URL sent over HTTP.
>
> The request will end like:
>
> "...?query=prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns"
>
> (space are illegal as well, as are < and > and ?,& have a different
> specific meaning)
>
> You need to encode the query string to include in HTTP.
>
> See the library your using for how to do this or better use a specific
> RDF/SPARQL library.
>
> For example for Python: rdflib
> http://rdflib3.readthedocs.io/en/latest/intro_to_sparql.html
>
> This returns code 404,
>>
>
> It returns 400 "Bad request", not 404 "Not Found"
>
> Andy
>
> and the server says:
>> [2016-09-04 14:42:17] Fuseki INFO [12] 400 Parse error:
>> prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns
>> Encountered " "<" "< "" at line 1, column 13.
>> Was expecting:
>> <IRIref> ...
>> (5 ms)
>>
>> I cannot help myself to debug this as I put one < for prefix which seems
>> to
>> be standard in SPARQL.
>>
>> *Does any of you know how to fix this problem?* (Still I would be very
>> happy to have an API doc.)
>>
>> Thanks for all the open sources and supports. It really helps me.
>>
>> With regards,
>> Jason Koh
>> cseweb.ucsd.edu/~jbkoh
>>
>>
Re: Fuseki REST API document?
Posted by Andy Seaborne <an...@apache.org>.
On 06/09/16 00:51, Jason Koh wrote:
> Hi there,
>
> I am Jason Koh, a PhD student at UCSD studying semantic web.
>
> I am trying to use Jena+Fuseki as it supports REST API directly, but I
> cannot find API documents for it. I was trying to do reverse-engineering,
> but it is too much. *Is there any REST API document of Fuseki?*
See the SPARQL protocol specification and SPARQL Graph Store Protocol.
Links at the top of:
http://jena.apache.org/documentation/fuseki2/
> Specific problem I currently face is following (in Python)
>
> 1) Working: requests.post('http://localhost:3030/myproject?query=SELECT
> ?anything WHERE{?anything ?aa ?bb} LIMIT 10')
>
> 2) Not working: requests.post('http://localhost:3030/myproject?query=
> 'prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> SELECT ?anything
> WHERE{?anything rdf:type ?bb} LIMIT 10'')
This is not a SPARQL problem.
The URL has a # in it - that's the start of a URL fragment and it is not
part of the URL sent over HTTP.
The request will end like:
"...?query=prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns"
(space are illegal as well, as are < and > and ?,& have a different
specific meaning)
You need to encode the query string to include in HTTP.
See the library your using for how to do this or better use a specific
RDF/SPARQL library.
For example for Python: rdflib
http://rdflib3.readthedocs.io/en/latest/intro_to_sparql.html
> This returns code 404,
It returns 400 "Bad request", not 404 "Not Found"
Andy
> and the server says:
> [2016-09-04 14:42:17] Fuseki INFO [12] 400 Parse error:
> prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns
> Encountered " "<" "< "" at line 1, column 13.
> Was expecting:
> <IRIref> ...
> (5 ms)
>
> I cannot help myself to debug this as I put one < for prefix which seems to
> be standard in SPARQL.
>
> *Does any of you know how to fix this problem?* (Still I would be very
> happy to have an API doc.)
>
> Thanks for all the open sources and supports. It really helps me.
>
> With regards,
> Jason Koh
> cseweb.ucsd.edu/~jbkoh
>