计算机科学论坛--新手急问：Sparql搜索RDF数据的简单问题

贴子主题：新手急问：Sparql搜索RDF数据的简单问题

本主题类别:

为了学习Sparql的功能，做了一个简单的model如下：
String ns = "http://www.comp.nus.edu.sg/dpf＃";
String rdfs = "http://www.w3.org/2000/01/rdf-schema#";

Model model = ModelFactory.createDefaultModel();
Resource resource1 =  model.createResource(ns + "TCP");
Resource resource2 =  model.createResource(ns + "Transport");
Resource resource3 =  model.createResource(ns + "Service");

Property property1 = model.createProperty(ns, "isChildOf");
Property property2 = model.createProperty(rdfs, "subClassOf");

Statement st1 = model.createStatement(resource1, property1, resource2);
Statement st2 = model.createStatement(resource2, property2, resource3);

model.add(st1);
model.add(st2);

然后我写了一个sparql的query语句如下：
String queryString =  "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> "
                       + "PREFIX ns:  <http://www.comp.nus.edu.sg/dpf/> "
                       + "SELECT ?out "
                       + "WHERE { "
                       + "?var rdfs:subClassOf ?out."
                       + "\"TCP\" ns:isChildOf ?var.}";
        Query query = QueryFactory.create(queryString);
        QueryExecution exc = QueryExecutionFactory.create(query, model);
        ResultSet result = exc.execSelect();
        ResultSetFormatter fsf = new ResultSetFormatter();
        ResultSetFormatter.out(System.out, result, query);

可是执行结果为空，百思不得其解，请高手赐教


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