问题描述
我在Android上使用jena向DBpedia发送查询.这是我的查询:
I use jena for android to send a query to DBpedia. This is my query:
protected Vector<List> doInBackground(String... keyword) {
VecDBpedia=new Vector();
vecurl= new ArrayList();
int i=0;
ResultSet results,re = null ;
QueryExecution exec = null ;
try{
do{
if(i!=VectorKeyWords.size())
{System.out.println(keyword[i]);
String sparqlQuery=
"PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>\n" +
"PREFIX dbo: <http://dbpedia.org/ontology/>\n" +
"PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> \n" +
"prefix foaf: <http://xmlns.com/foaf/0.1/> \n"+
"PREFIX dbpprop: <http://dbpedia.org/property/>\n"+
"select distinct ?nbr ?Nom ?resource ?url where {\n" +
"?resource rdfs:label ?Nom.\n" +
"?resource foaf:isPrimaryTopicOf ?url.\n" +
"?resource dbo:abstract ?resume.\n"+
"FILTER langMatches( lang(?Nom), \"EN\") .\n" +
"FILTER langMatches( lang(?resume), \"EN\" )\n"+
"?Nom <bif:contains> \"Apple\".\n"+
"bind(strlen(replace(replace(Lcase(?resume), \"jobs\", \"_\"),\"[^_]\", \"\")) as ?nbr )\n"+
"filter (?nbr >= 1)\n"+
"}" ;
String service= "http://dbpedia.org/sparql";
Query qur=QueryFactory.create(sparqlQuery,Syntax.syntaxARQ);
System.out.print("sparqlQuery"+sparqlQuery);
exec =QueryExecutionFactory.sparqlService(service,qur );
System.out.print("qur"+qur);
re =exec.execSelect();
System.out.print("re"+re);
i++;
System.out.println(re.hasNext());}
} while(re.hasNext()==false && i<VectorKeyWords.size());
if(i==VectorKeyWords.size()) //si aucun des mot clé ne se trouve dans DBpedia
{ System.out.println("Aucun mot clé ne correspond à une entrée en DBpedia");
cancel(true);// A vérifier
finish();}
results = ResultSetFactory.copyResults( re );
ResultSetFormatter.out( results );
while ( results.hasNext() ) {
ArrayList<String> listDBpediaResource=new ArrayList();
QuerySolution node= results.next();
RDFNode colonne1=node.get( "Nom" );
RDFNode colonne2=node.get( "resource" );
RDFNode colonne3=node.get( "url" );
// RDFNode s2= results.next().get( "url" );
listDBpediaResource.add(colonne2.toString());
listDBpediaResource.add(colonne3.toString());
listDBpediaResource.add(colonne1.toString());
VecDBpedia.add(listDBpediaResource);
vecurl.add(colonne3.toString());//creer un vecteur contenant les url de chaque ressource condidat de dbpedia
}
} catch (Exception e) {
e.printStackTrace();
}
finally{exec.close();}
return VecDBpedia;
}
;
此查询可在SPARQL端点以及Java应用程序中运行，但不适用于android应用程序.
this query works at SPARQL endpoint, and also in a java application, but does'nt work in android application.
我在执行代码时收到此消息:
I get this message while executing the code:
W/System.err(8123): com.hp.hpl.jena.query.QueryParseException: Lexical error at line 13, column 5. Encountered: "(" (40), after : "bind"
W/System.err(8123): at com.hp.hpl.jena.sparql.lang.ParserARQ.perform(ParserARQ.java:95)
W/System.err(8123):at com.hp.hpl.jena.sparql.lang.ParserARQ.parse(ParserARQ.java:39)
W/System.err(8123): at com.hp.hpl.jena.query.QueryFactory.parse(QueryFactory.java:129)
W/System.err(8123): at com.hp.hpl.jena.query.QueryFactory.create(QueryFactory.java:72)
W/System.err(8123): at com.hp.hpl.jena.query.QueryFactory.create(QueryFactory.java:43)
W/System.err(8123): at com.example.testtvprg.MainActivity$AsyncDBpedia.doInBackground(MainActivity.java:426)
W/System.err(8123): at com.example.testtvprg.MainActivity$AsyncDBpedia.doInBackground(MainActivity.java:1)
W/System.err(8123): at android.os.AsyncTask$2.call(AsyncTask.java:287)
W/System.err(8123): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
W/System.err(8123): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
W/System.err(8123): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
W/System.err(8123): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
W/System.err(8123): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
W/System.err(8123): at java.lang.Thread.run(Thread.java:856)
我认为这是耶拿或arq版本的问题，但我不知道如何纠正它.任何人都可以帮助我.谢谢
I think that it's a problem of jena or arq version, but i don't know how to correct it.Any one can help me please.Thanks
推荐答案
所有想帮助我的人都想一下.我最终决定更改查询的功能BIND，因为它不适用于QueryExecutionFactory.sparqlService也不适用于QueryEngineHttp.这是一个临时解决方案，因为可能是我需要具有相同问题的其他功能.如果有人知道解决方案，我将不胜感激.
Thinks to all those wanted to help me. I finally decide to change the function BIND of the query, because it doesn't work with QueryExecutionFactory.sparqlService neither with QueryEngineHttp. It's a temporary solution, because may be i would need to other functions that will have the same problem. If anyone knows a solution , i will be grateful.
这篇关于使用Jena API绑定SPARQL中的函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！