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Posted to users@jena.apache.org by Luis Enrique Ramos García <lu...@googlemail.com.INVALID> on 2020/04/09 12:47:23 UTC
issue trying to query wikidata with jena api
dear member of jena community,
I have been trying to query wikidata following the documentation [1] and
other examples I have found, but result obtained has been null values,
besides it is a simple query, that I have just previously tested in the
wikidata query GUI.
I followed two methods, one with QueryExecution, and another
with RDFConnectionRemote, but however in both the output is null as well.
Please, let me know if I am missing something, or if I am going in the
wrong direction.
Best regards
Luis Ramos
*CODE *
import org.apache.jena.query.Query;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QueryFactory;
import org.apache.jena.query.QuerySolution;
import org.apache.jena.query.ResultSet;
import org.apache.jena.rdf.model.Resource;
import org.apache.jena.rdfconnection.RDFConnection;
import org.apache.jena.rdfconnection.RDFConnectionFactory;
import org.apache.jena.rdfconnection.RDFConnectionRemote;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
/*
* Example of a building a remote connection.
*/
public class RDFConnectionExample4 {
//testing
static Logger log = Logger.getLogger(RDFConnectionExample4.class);
public static void main(String ...args) {
log.setLevel(Level.INFO);
log.info("This is Luis Logger");
BasicConfigurator.configure();
String my_query = "PREFIX schema: <http://schema.org/>\n" +
"PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>\n" +
"PREFIX owl: <http://www.w3.org/2002/07/owl#>\n" +
"PREFIX hist: <http://wikiba.se/history/ontology#>\n" +
"PREFIX wd: <http://www.wikidata.org/entity/>\n" +
"PREFIX wdt: <http://www.wikidata.org/prop/direct/>\n" +
"PREFIX wikibase: <http://wikiba.se/ontology#>\n" +
"PREFIX dct: <http://purl.org/dc/terms/>\n" +
"\n" +
"SELECT ?item1 WHERE {\n" +
" ?item1 wdt:P31 ?item2.\n" +
"} LIMIT 10";
System.out
.println("The query string is"+ my_query);
Query query = QueryFactory.create(my_query);
//method 1 with query execution
QueryExecution qe1 = QueryExecutionFactory.sparqlService("
https://query.wikidata.org/sparql", query);
ResultSet rs1 = qe1.execSelect() ;
while(rs1.hasNext()) {
QuerySolution qs1 = rs1.next() ;
Resource subject1 = qs1.getResource("s") ;
System.out.println("Subject: "+subject1) ;
}
//method 2
RDFConnection conn0 = RDFConnectionRemote.create()
.destination("https://query.wikidata.org/")
.queryEndpoint("sparql")
// Set a specific accept header; here, sparql-results+json
(preferred) and text/tab-separated-values
//The default is "application/sparql-results+json,
application/sparql-results+xml;q=0.9, text/tab-separated-values;q=0.7,
text/csv;q=0.5, application/json;q=0.2, application/xml;q=0.2, */*;q=0.1"
.acceptHeaderSelectQuery("application/sparql-results+json,
application/sparql-results+xml;q=0.9")
.build();
String queryService = "https://query.wikidata.org/sparql?";
RDFConnection conn = RDFConnectionFactory.connect(queryService,
null, null);
QueryExecution qe2 = conn.query(query);
ResultSet rs2 = qe2.execSelect() ;
while(rs2.hasNext()) {
QuerySolution qs2 = rs2.next() ;
Resource subject2 = qs2.getResource("s") ;
System.out.println("Subject: "+subject2) ;
}
// QueryExecution qExec = conn.query(query);
}
https://jena.apache.org/documentation/rdfconnection/
Re: issue trying to query wikidata with jena api
Posted by Luis Enrique Ramos García <lu...@googlemail.com.INVALID>.
solved! 🙄
Luis
El jue., 9 abr. 2020 a las 15:03, Andy Seaborne (<an...@apache.org>)
escribió:
> > "SELECT ?item1 WHERE {\n" +
> > " ?item1 wdt:P31 ?item2.\n" +
> > "} LIMIT 10";
>
>
> > qs1.getResource("s")
>
> The variable is called "item1"
>
> qs1.getResource("item1")
>
> Andy
>
> On 09/04/2020 13:47, Luis Enrique Ramos García wrote:
> > dear member of jena community,
> >
> > I have been trying to query wikidata following the documentation [1] and
> > other examples I have found, but result obtained has been null values,
> > besides it is a simple query, that I have just previously tested in the
> > wikidata query GUI.
> >
> > I followed two methods, one with QueryExecution, and another
> > with RDFConnectionRemote, but however in both the output is null as well.
> >
> > Please, let me know if I am missing something, or if I am going in the
> > wrong direction.
> >
> >
> > Best regards
> >
> >
> >
> > Luis Ramos
> >
> >
> > *CODE *
> >
> >
> >
> > import org.apache.jena.query.Query;
> > import org.apache.jena.query.QueryExecution;
> > import org.apache.jena.query.QueryExecutionFactory;
> > import org.apache.jena.query.QueryFactory;
> > import org.apache.jena.query.QuerySolution;
> > import org.apache.jena.query.ResultSet;
> > import org.apache.jena.rdf.model.Resource;
> > import org.apache.jena.rdfconnection.RDFConnection;
> > import org.apache.jena.rdfconnection.RDFConnectionFactory;
> > import org.apache.jena.rdfconnection.RDFConnectionRemote;
> > import org.apache.log4j.BasicConfigurator;
> > import org.apache.log4j.Level;
> > import org.apache.log4j.Logger;
> >
> >
> >
> >
> > /*
> > * Example of a building a remote connection.
> >
> > */
> > public class RDFConnectionExample4 {
> >
> > //testing
> > static Logger log = Logger.getLogger(RDFConnectionExample4.class);
> >
> >
> >
> >
> > public static void main(String ...args) {
> >
> > log.setLevel(Level.INFO);
> > log.info("This is Luis Logger");
> > BasicConfigurator.configure();
> >
> >
> >
> > String my_query = "PREFIX schema: <http://schema.org/>\n" +
> > "PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>\n" +
> > "PREFIX owl: <http://www.w3.org/2002/07/owl#>\n" +
> > "PREFIX hist: <http://wikiba.se/history/ontology#>\n" +
> > "PREFIX wd: <http://www.wikidata.org/entity/>\n" +
> > "PREFIX wdt: <http://www.wikidata.org/prop/direct/>\n" +
> > "PREFIX wikibase: <http://wikiba.se/ontology#>\n" +
> > "PREFIX dct: <http://purl.org/dc/terms/>\n" +
> > "\n" +
> > "SELECT ?item1 WHERE {\n" +
> > " ?item1 wdt:P31 ?item2.\n" +
> > "} LIMIT 10";
> >
> > System.out
> >
> > .println("The query string is"+ my_query);
> >
> > Query query = QueryFactory.create(my_query);
> >
> > //method 1 with query execution
> >
> > QueryExecution qe1 = QueryExecutionFactory.sparqlService("
> > https://query.wikidata.org/sparql", query);
> >
> > ResultSet rs1 = qe1.execSelect() ;
> >
> > while(rs1.hasNext()) {
> > QuerySolution qs1 = rs1.next() ;
> > Resource subject1 = qs1.getResource("s") ;
> > System.out.println("Subject: "+subject1) ;
> > }
> >
> > //method 2
> >
> >
> >
> >
> > RDFConnection conn0 = RDFConnectionRemote.create()
> > .destination("https://query.wikidata.org/")
> > .queryEndpoint("sparql")
> > // Set a specific accept header; here, sparql-results+json
> > (preferred) and text/tab-separated-values
> > //The default is "application/sparql-results+json,
> > application/sparql-results+xml;q=0.9, text/tab-separated-values;q=0.7,
> > text/csv;q=0.5, application/json;q=0.2, application/xml;q=0.2, */*;q=0.1"
> > .acceptHeaderSelectQuery("application/sparql-results+json,
> > application/sparql-results+xml;q=0.9")
> > .build();
> >
> >
> > String queryService = "https://query.wikidata.org/sparql?";
> >
> > RDFConnection conn = RDFConnectionFactory.connect(queryService,
> > null, null);
> >
> > QueryExecution qe2 = conn.query(query);
> >
> > ResultSet rs2 = qe2.execSelect() ;
> >
> > while(rs2.hasNext()) {
> > QuerySolution qs2 = rs2.next() ;
> > Resource subject2 = qs2.getResource("s") ;
> > System.out.println("Subject: "+subject2) ;
> > }
> >
> >
> >
> > // QueryExecution qExec = conn.query(query);
> >
> >
> > }
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > https://jena.apache.org/documentation/rdfconnection/
> >
>
Re: issue trying to query wikidata with jena api
Posted by Andy Seaborne <an...@apache.org>.
The URL is sending back HTML.
Probably means it is a URL to a form for asking SPARQL queries, not the
SPARQL endpoint itself. See if you can find out where the form sends
the query.
Andy
On 09/04/2020 14:29, Luis Enrique Ramos García wrote:
> Andy,
>
> In addition I am working in another end point, and now I am getting this
> output:
>
> Endpoint returned Content-Type: text/html which is not rcognized for SELECT
> queries
>
> I followed this recommendation
>
> https://stackoverflow.com/questions/41926530/jena-endpoint-returned-content-type-text-html
>
>
> however the behavior does not change, and I continue receiving this error:
>
> Exception in thread "main" org.apache.jena.query.QueryException: Endpoint
> returned Content-Type: text/html which is not rcognized for SELECT queries
> at
> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execResultSetInner(QueryEngineHTTP.java:377)
> at
> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execSelect(QueryEngineHTTP.java:345)
> at
> ag.pst.jena.test.RDFConnectionExample4.main(RDFConnectionExample4.java:84)
>
> any recommendation?
>
>
> Luis
>
> El jue., 9 abr. 2020 a las 15:03, Andy Seaborne (<an...@apache.org>)
> escribió:
>
>>> "SELECT ?item1 WHERE {\n" +
>>> " ?item1 wdt:P31 ?item2.\n" +
>>> "} LIMIT 10";
>>
>>
>>> qs1.getResource("s")
>>
>> The variable is called "item1"
>>
>> qs1.getResource("item1")
>>
>> Andy
>>
>> On 09/04/2020 13:47, Luis Enrique Ramos García wrote:
>>> dear member of jena community,
>>>
>>> I have been trying to query wikidata following the documentation [1] and
>>> other examples I have found, but result obtained has been null values,
>>> besides it is a simple query, that I have just previously tested in the
>>> wikidata query GUI.
>>>
>>> I followed two methods, one with QueryExecution, and another
>>> with RDFConnectionRemote, but however in both the output is null as well.
>>>
>>> Please, let me know if I am missing something, or if I am going in the
>>> wrong direction.
>>>
>>>
>>> Best regards
>>>
>>>
>>>
>>> Luis Ramos
>>>
>>>
>>> *CODE *
>>>
>>>
>>>
>>> import org.apache.jena.query.Query;
>>> import org.apache.jena.query.QueryExecution;
>>> import org.apache.jena.query.QueryExecutionFactory;
>>> import org.apache.jena.query.QueryFactory;
>>> import org.apache.jena.query.QuerySolution;
>>> import org.apache.jena.query.ResultSet;
>>> import org.apache.jena.rdf.model.Resource;
>>> import org.apache.jena.rdfconnection.RDFConnection;
>>> import org.apache.jena.rdfconnection.RDFConnectionFactory;
>>> import org.apache.jena.rdfconnection.RDFConnectionRemote;
>>> import org.apache.log4j.BasicConfigurator;
>>> import org.apache.log4j.Level;
>>> import org.apache.log4j.Logger;
>>>
>>>
>>>
>>>
>>> /*
>>> * Example of a building a remote connection.
>>>
>>> */
>>> public class RDFConnectionExample4 {
>>>
>>> //testing
>>> static Logger log = Logger.getLogger(RDFConnectionExample4.class);
>>>
>>>
>>>
>>>
>>> public static void main(String ...args) {
>>>
>>> log.setLevel(Level.INFO);
>>> log.info("This is Luis Logger");
>>> BasicConfigurator.configure();
>>>
>>>
>>>
>>> String my_query = "PREFIX schema: <http://schema.org/>\n" +
>>> "PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>\n" +
>>> "PREFIX owl: <http://www.w3.org/2002/07/owl#>\n" +
>>> "PREFIX hist: <http://wikiba.se/history/ontology#>\n" +
>>> "PREFIX wd: <http://www.wikidata.org/entity/>\n" +
>>> "PREFIX wdt: <http://www.wikidata.org/prop/direct/>\n" +
>>> "PREFIX wikibase: <http://wikiba.se/ontology#>\n" +
>>> "PREFIX dct: <http://purl.org/dc/terms/>\n" +
>>> "\n" +
>>> "SELECT ?item1 WHERE {\n" +
>>> " ?item1 wdt:P31 ?item2.\n" +
>>> "} LIMIT 10";
>>>
>>> System.out
>>>
>>> .println("The query string is"+ my_query);
>>>
>>> Query query = QueryFactory.create(my_query);
>>>
>>> //method 1 with query execution
>>>
>>> QueryExecution qe1 = QueryExecutionFactory.sparqlService("
>>> https://query.wikidata.org/sparql", query);
>>>
>>> ResultSet rs1 = qe1.execSelect() ;
>>>
>>> while(rs1.hasNext()) {
>>> QuerySolution qs1 = rs1.next() ;
>>> Resource subject1 = qs1.getResource("s") ;
>>> System.out.println("Subject: "+subject1) ;
>>> }
>>>
>>> //method 2
>>>
>>>
>>>
>>>
>>> RDFConnection conn0 = RDFConnectionRemote.create()
>>> .destination("https://query.wikidata.org/")
>>> .queryEndpoint("sparql")
>>> // Set a specific accept header; here, sparql-results+json
>>> (preferred) and text/tab-separated-values
>>> //The default is "application/sparql-results+json,
>>> application/sparql-results+xml;q=0.9, text/tab-separated-values;q=0.7,
>>> text/csv;q=0.5, application/json;q=0.2, application/xml;q=0.2, */*;q=0.1"
>>> .acceptHeaderSelectQuery("application/sparql-results+json,
>>> application/sparql-results+xml;q=0.9")
>>> .build();
>>>
>>>
>>> String queryService = "https://query.wikidata.org/sparql?";
>>>
>>> RDFConnection conn = RDFConnectionFactory.connect(queryService,
>>> null, null);
>>>
>>> QueryExecution qe2 = conn.query(query);
>>>
>>> ResultSet rs2 = qe2.execSelect() ;
>>>
>>> while(rs2.hasNext()) {
>>> QuerySolution qs2 = rs2.next() ;
>>> Resource subject2 = qs2.getResource("s") ;
>>> System.out.println("Subject: "+subject2) ;
>>> }
>>>
>>>
>>>
>>> // QueryExecution qExec = conn.query(query);
>>>
>>>
>>> }
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> https://jena.apache.org/documentation/rdfconnection/
>>>
>>
>
Re: issue trying to query wikidata with jena api
Posted by Luis Enrique Ramos García <lu...@googlemail.com.INVALID>.
Andy,
In addition I am working in another end point, and now I am getting this
output:
Endpoint returned Content-Type: text/html which is not rcognized for SELECT
queries
I followed this recommendation
https://stackoverflow.com/questions/41926530/jena-endpoint-returned-content-type-text-html
however the behavior does not change, and I continue receiving this error:
Exception in thread "main" org.apache.jena.query.QueryException: Endpoint
returned Content-Type: text/html which is not rcognized for SELECT queries
at
org.apache.jena.sparql.engine.http.QueryEngineHTTP.execResultSetInner(QueryEngineHTTP.java:377)
at
org.apache.jena.sparql.engine.http.QueryEngineHTTP.execSelect(QueryEngineHTTP.java:345)
at
ag.pst.jena.test.RDFConnectionExample4.main(RDFConnectionExample4.java:84)
any recommendation?
Luis
El jue., 9 abr. 2020 a las 15:03, Andy Seaborne (<an...@apache.org>)
escribió:
> > "SELECT ?item1 WHERE {\n" +
> > " ?item1 wdt:P31 ?item2.\n" +
> > "} LIMIT 10";
>
>
> > qs1.getResource("s")
>
> The variable is called "item1"
>
> qs1.getResource("item1")
>
> Andy
>
> On 09/04/2020 13:47, Luis Enrique Ramos García wrote:
> > dear member of jena community,
> >
> > I have been trying to query wikidata following the documentation [1] and
> > other examples I have found, but result obtained has been null values,
> > besides it is a simple query, that I have just previously tested in the
> > wikidata query GUI.
> >
> > I followed two methods, one with QueryExecution, and another
> > with RDFConnectionRemote, but however in both the output is null as well.
> >
> > Please, let me know if I am missing something, or if I am going in the
> > wrong direction.
> >
> >
> > Best regards
> >
> >
> >
> > Luis Ramos
> >
> >
> > *CODE *
> >
> >
> >
> > import org.apache.jena.query.Query;
> > import org.apache.jena.query.QueryExecution;
> > import org.apache.jena.query.QueryExecutionFactory;
> > import org.apache.jena.query.QueryFactory;
> > import org.apache.jena.query.QuerySolution;
> > import org.apache.jena.query.ResultSet;
> > import org.apache.jena.rdf.model.Resource;
> > import org.apache.jena.rdfconnection.RDFConnection;
> > import org.apache.jena.rdfconnection.RDFConnectionFactory;
> > import org.apache.jena.rdfconnection.RDFConnectionRemote;
> > import org.apache.log4j.BasicConfigurator;
> > import org.apache.log4j.Level;
> > import org.apache.log4j.Logger;
> >
> >
> >
> >
> > /*
> > * Example of a building a remote connection.
> >
> > */
> > public class RDFConnectionExample4 {
> >
> > //testing
> > static Logger log = Logger.getLogger(RDFConnectionExample4.class);
> >
> >
> >
> >
> > public static void main(String ...args) {
> >
> > log.setLevel(Level.INFO);
> > log.info("This is Luis Logger");
> > BasicConfigurator.configure();
> >
> >
> >
> > String my_query = "PREFIX schema: <http://schema.org/>\n" +
> > "PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>\n" +
> > "PREFIX owl: <http://www.w3.org/2002/07/owl#>\n" +
> > "PREFIX hist: <http://wikiba.se/history/ontology#>\n" +
> > "PREFIX wd: <http://www.wikidata.org/entity/>\n" +
> > "PREFIX wdt: <http://www.wikidata.org/prop/direct/>\n" +
> > "PREFIX wikibase: <http://wikiba.se/ontology#>\n" +
> > "PREFIX dct: <http://purl.org/dc/terms/>\n" +
> > "\n" +
> > "SELECT ?item1 WHERE {\n" +
> > " ?item1 wdt:P31 ?item2.\n" +
> > "} LIMIT 10";
> >
> > System.out
> >
> > .println("The query string is"+ my_query);
> >
> > Query query = QueryFactory.create(my_query);
> >
> > //method 1 with query execution
> >
> > QueryExecution qe1 = QueryExecutionFactory.sparqlService("
> > https://query.wikidata.org/sparql", query);
> >
> > ResultSet rs1 = qe1.execSelect() ;
> >
> > while(rs1.hasNext()) {
> > QuerySolution qs1 = rs1.next() ;
> > Resource subject1 = qs1.getResource("s") ;
> > System.out.println("Subject: "+subject1) ;
> > }
> >
> > //method 2
> >
> >
> >
> >
> > RDFConnection conn0 = RDFConnectionRemote.create()
> > .destination("https://query.wikidata.org/")
> > .queryEndpoint("sparql")
> > // Set a specific accept header; here, sparql-results+json
> > (preferred) and text/tab-separated-values
> > //The default is "application/sparql-results+json,
> > application/sparql-results+xml;q=0.9, text/tab-separated-values;q=0.7,
> > text/csv;q=0.5, application/json;q=0.2, application/xml;q=0.2, */*;q=0.1"
> > .acceptHeaderSelectQuery("application/sparql-results+json,
> > application/sparql-results+xml;q=0.9")
> > .build();
> >
> >
> > String queryService = "https://query.wikidata.org/sparql?";
> >
> > RDFConnection conn = RDFConnectionFactory.connect(queryService,
> > null, null);
> >
> > QueryExecution qe2 = conn.query(query);
> >
> > ResultSet rs2 = qe2.execSelect() ;
> >
> > while(rs2.hasNext()) {
> > QuerySolution qs2 = rs2.next() ;
> > Resource subject2 = qs2.getResource("s") ;
> > System.out.println("Subject: "+subject2) ;
> > }
> >
> >
> >
> > // QueryExecution qExec = conn.query(query);
> >
> >
> > }
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > https://jena.apache.org/documentation/rdfconnection/
> >
>
Re: issue trying to query wikidata with jena api
Posted by Andy Seaborne <an...@apache.org>.
> "SELECT ?item1 WHERE {\n" +
> " ?item1 wdt:P31 ?item2.\n" +
> "} LIMIT 10";
> qs1.getResource("s")
The variable is called "item1"
qs1.getResource("item1")
Andy
On 09/04/2020 13:47, Luis Enrique Ramos García wrote:
> dear member of jena community,
>
> I have been trying to query wikidata following the documentation [1] and
> other examples I have found, but result obtained has been null values,
> besides it is a simple query, that I have just previously tested in the
> wikidata query GUI.
>
> I followed two methods, one with QueryExecution, and another
> with RDFConnectionRemote, but however in both the output is null as well.
>
> Please, let me know if I am missing something, or if I am going in the
> wrong direction.
>
>
> Best regards
>
>
>
> Luis Ramos
>
>
> *CODE *
>
>
>
> import org.apache.jena.query.Query;
> import org.apache.jena.query.QueryExecution;
> import org.apache.jena.query.QueryExecutionFactory;
> import org.apache.jena.query.QueryFactory;
> import org.apache.jena.query.QuerySolution;
> import org.apache.jena.query.ResultSet;
> import org.apache.jena.rdf.model.Resource;
> import org.apache.jena.rdfconnection.RDFConnection;
> import org.apache.jena.rdfconnection.RDFConnectionFactory;
> import org.apache.jena.rdfconnection.RDFConnectionRemote;
> import org.apache.log4j.BasicConfigurator;
> import org.apache.log4j.Level;
> import org.apache.log4j.Logger;
>
>
>
>
> /*
> * Example of a building a remote connection.
>
> */
> public class RDFConnectionExample4 {
>
> //testing
> static Logger log = Logger.getLogger(RDFConnectionExample4.class);
>
>
>
>
> public static void main(String ...args) {
>
> log.setLevel(Level.INFO);
> log.info("This is Luis Logger");
> BasicConfigurator.configure();
>
>
>
> String my_query = "PREFIX schema: <http://schema.org/>\n" +
> "PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>\n" +
> "PREFIX owl: <http://www.w3.org/2002/07/owl#>\n" +
> "PREFIX hist: <http://wikiba.se/history/ontology#>\n" +
> "PREFIX wd: <http://www.wikidata.org/entity/>\n" +
> "PREFIX wdt: <http://www.wikidata.org/prop/direct/>\n" +
> "PREFIX wikibase: <http://wikiba.se/ontology#>\n" +
> "PREFIX dct: <http://purl.org/dc/terms/>\n" +
> "\n" +
> "SELECT ?item1 WHERE {\n" +
> " ?item1 wdt:P31 ?item2.\n" +
> "} LIMIT 10";
>
> System.out
>
> .println("The query string is"+ my_query);
>
> Query query = QueryFactory.create(my_query);
>
> //method 1 with query execution
>
> QueryExecution qe1 = QueryExecutionFactory.sparqlService("
> https://query.wikidata.org/sparql", query);
>
> ResultSet rs1 = qe1.execSelect() ;
>
> while(rs1.hasNext()) {
> QuerySolution qs1 = rs1.next() ;
> Resource subject1 = qs1.getResource("s") ;
> System.out.println("Subject: "+subject1) ;
> }
>
> //method 2
>
>
>
>
> RDFConnection conn0 = RDFConnectionRemote.create()
> .destination("https://query.wikidata.org/")
> .queryEndpoint("sparql")
> // Set a specific accept header; here, sparql-results+json
> (preferred) and text/tab-separated-values
> //The default is "application/sparql-results+json,
> application/sparql-results+xml;q=0.9, text/tab-separated-values;q=0.7,
> text/csv;q=0.5, application/json;q=0.2, application/xml;q=0.2, */*;q=0.1"
> .acceptHeaderSelectQuery("application/sparql-results+json,
> application/sparql-results+xml;q=0.9")
> .build();
>
>
> String queryService = "https://query.wikidata.org/sparql?";
>
> RDFConnection conn = RDFConnectionFactory.connect(queryService,
> null, null);
>
> QueryExecution qe2 = conn.query(query);
>
> ResultSet rs2 = qe2.execSelect() ;
>
> while(rs2.hasNext()) {
> QuerySolution qs2 = rs2.next() ;
> Resource subject2 = qs2.getResource("s") ;
> System.out.println("Subject: "+subject2) ;
> }
>
>
>
> // QueryExecution qExec = conn.query(query);
>
>
> }
>
>
>
>
>
>
>
>
>
>
>
>
> https://jena.apache.org/documentation/rdfconnection/
>