我正在尝试执行一个非常简单的SPARQL查询，根据传递在查询字符串中的姓名检索一个人的国籍，但我不明白为什么它不能工作。以下是相关的RDF规则...
<owl:DatatypeProperty rdf:ID="name">
<rdfs:domain rdf:resource="#NobelWinner"/>
<rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
<rdfs:comment rdf:datatype="http://www.w3.org/2001/XMLSchema#string">All laureates have a name.</rdfs:comment>
</owl:DatatypeProperty>
<owl:DatatypeProperty rdf:ID="nationality">
<rdfs:domain rdf:resource="#PersonWinner"/>
<rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
<rdfs:comment rdf:datatype="http://www.w3.org/2001/XMLSchema#string">
Person laureates were associated with a nation when they won the prize.
</rdfs:comment>
</owl:DatatypeProperty>
代码位于Java servlet中，类似于以下内容，其中SPARQL查询在第42行...
try {
34 String prefix1 = "PREFIX nob:<http://swat.cse.lehigh.edu/resources/onto/nobel.owl#> ";
35 String prefix2 = "PREFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#> ";
36 String prefix3 = "PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> ";
37 String prefix4 = "PREFIX nobdat:<http://swat.cse.lehigh.edu/resources/data/nobel/nobeldata.owl#> ";
38 String prefix = prefix1+prefix2+prefix3+prefix4;
39 String winnerName = request.getParameter("name");
40
41 // INSERT QUERY
42 String queryString = prefix +
43 "SELECT ?nat { ?s nob:name " + winnerName + ". ?s nob:nationality ?nat. }";
44
45 String ttlLoc = "/my/ttl/path/loc.ttl";
47 Store store = SDBFactory.connectStore(ttlLoc);
48 Dataset ds = DatasetStore.create(store) ;
49
50 // CREATE QUERY
51 Query query = QueryFactory.create(queryString);
52 QueryExecution qe = QueryExecutionFactory.create(query, ds);
while (rs.hasNext()) {
66 QuerySolution qs = rs.nextSolution();
67 String nationality = qs.getLiteral("?nat").toString();
68 out.println("<P>Nationality: " + nationality + "</P>");
69 }
我在Protege IDE中无法使用查询或任何类似的东西，该查询将字符串字面量替换为名称。有什么想法吗？谢谢大家。