如何从 QueryExecution 生成的 ResultSet 中检索 Jena RDFNode?运行查询后,我能够看到正确的 ResultSet,但结果仅提供节点的 URI,谁能告诉我需要做什么才能获取 RDF 节点详细信息。这将让我提取以后可以操作的每个属性。我看到的解决方法是使用显示实例属性而不是实例本身的查询。
当前结果:
http://assignment3.stdi.msmsuhail.ead/bpl.owl#Arsenal
预期结果:
<rdf:Description rdf:about="http://assignment3.stdi.msmsuhail.ead/bpl.owl#Arsenal">
<bpl:hasStadiumLocation rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Holloway</bpl:hasStadiumLocation>
<rdf:type rdf:resource="http://assignment3.stdi.msmsuhail.ead/bpl.owl#Clubs"/>
<rdf:type rdf:resource="http://www.w3.org/2002/07/owl#NamedIndividual"/>
<bpl:hasStadiumName rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Emirates Stadium</bpl:hasStadiumName>
<bpl:hasPlayer rdf:resource="http://assignment3.stdi.msmsuhail.ead/bpl.owl#TheoWalcott"/>
<bpl:hasPlayer rdf:resource="http://assignment3.stdi.msmsuhail.ead/bpl.owl#MikelArteta"/>
<bpl:hasName rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Arsenal</bpl:hasName>
<bpl:hasNumberSeats rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">60355</bpl:hasNumberSeats>
<bpl:hasManager rdf:resource="http://assignment3.stdi.msmsuhail.ead/bpl.owl#ArseneWenger"/>
<bpl:hasPlayer rdf:resource="http://assignment3.stdi.msmsuhail.ead/bpl.owl#AaronRamsey"/>
</rdf:Description>
SPARQL 查询:
SELECT DISTINCT ?clubs ?clubName
WHERE {
?Club bpl:hasPlayer ?players.
?Club bpl:hasManager ?managers.
?players bpl:hasClub ?clubs .
?players bpl:hasAge ?playerAge.
?players bpl:hasName ?playerName.
?players bpl:hasNationality ?playerNationality.
?players bpl:hasPlayingPosition ?playerPosition.
?players bpl:isRetired ?playerIsRetired.
?clubs bpl:hasName ?clubName.
?clubs bpl:hasNumberSeats ?clubSeats.
?clubs bpl:hasStadiumName ?clubStadiumName .
?clubs bpl:hasStadiumLocation ?clubStadiumLocation.
?managers bpl:hasAge ?managerAge.
?managers bpl:hasName ?managerName.
?managers bpl:hasNationality ?managerNationality.
?managers bpl:isManager ?isManager.
}
ORDER BY ASC (?clubName)
Java 代码:
while(resultSet!=null && resultSet.hasNext()){
QuerySolution querySolution = resultSet.nextSolution();
System.out.println(querySolution.get("clubs").toString());
}