parse a sparql json result set to a TupleQueryResult

[D063520]

Hi, I'm struggling in parsing a sparql json result string to a TupleQueryResult. Can someone help me out?

[barthanssens]

Sure, is there some part of the code you'd be willing to share ?

FWIW, depending on what you want to achieve, it could be worthwhile to look into some of the Repositories convenience methods (e.g just getting the results as a list: https://rdf4j.org/documentation/programming/repository/#a-tuple-query-in-a-single-line-of-code-the-repositories-utility)

[D063520]

Hi : ),

sorry ... there is not so much code to share. I have a file containing something like this:

{
"head" : {
"vars" : [
"prg",
"cci",
"totp",
"totbdg"
]
},
"results" : {
"bindings" : [
{
"totp" : {
"datatype" : "http://www.w3.org/2001/XMLSchema#integer",
"type" : "literal",
"value" : "33286"
},
"prg" : {
"type" : "uri",
"value" : "https://linkedopendata.eu/entity/Q2463066"
},
"cci" : {
"type" : "literal",
"value" : "2014BG16RFOP002"
},
"totbdg" : {
"datatype" : "http://www.w3.org/2001/XMLSchema#decimal",
"type" : "literal",
"value" : "2340209884.15"
}
},
{
"totp" : {
"datatype" : "http://www.w3.org/2001/XMLSchema#integer",
"type" : "literal",
"value" : "66"
},
"prg" : {
"type" : "uri",
"value" : "https://linkedopendata.eu/entity/Q2463063"
},
"cci" : {
"type" : "literal",
"value" : "2014BG16M1OP001"
},
"totbdg" : {
"datatype" : "http://www.w3.org/2001/XMLSchema#decimal",
"type" : "literal",
"value" : "1997197541.69"
}
},

and I want to get out of it a TupleQueryResult?

[hmottestad]

How did you produce this file?

[D063520]

it is the result of a sparql query that I stored to disk ....

[hmottestad]

I think the easiest solution is to rerun the query against your SPARQL endpoint through an RDF4J SPARQLRepository: https://rdf4j.org/documentation/programming/repository/#sparql-endpoints

[hmottestad]

Some digging into the code turned up SPARQLResultsJSONParserFactory. But this is deep into the internals of RDF4J and not something I would recommend you consider using unless you are comfortable with figuring out a bunch of mostly undocumented code.

[D063520]

@hmottestad thank you for the pointer! I managed with

SPARQLResultsJSONParser sparqlResultsJSONParser = new SPARQLResultsJSONParser();
TupleQueryResultBuilder tupleQueryResultHandler = new TupleQueryResultBuilder();
sparqlResultsJSONParser.setQueryResultHandler(tupleQueryResultHandler);
sparqlResultsJSONParser.parseQueryResult(inputstream);
TupleQueryResult tupleQueryResult = tupleQueryResultHandler.getQueryResult();