Java Jena：得到一个空的结果集

当我试图检索存储在jena模型中的数据时，得到的结果集是空的

这是加载数据的代码（为了简洁起见，我删除了导入）

这就是我从java程序读取数据的方式

public class ReadBasicQn {
public static void main(String[] args) {
    String directory = "D:/mywork/dp/projs/static-risks/data/test";
    Dataset dataset = TDBFactory.createDataset(directory);

    Model model = null;
    ResultSet rs;
    QueryExecution qexeExecution = null;
    try{
        /*model = ModelFactory.createDefaultModel();
        TDBLoader.loadModel(model, directory + "/Project_risk.ttl");*/

        model = dataset.getDefaultModel();

        String queryString = "PREFIX proj: <http://www.abc123.com/riskmodelling/static/risks#> ";
        queryString += "select ?risks where ";
        queryString += "{proj:PROJECT_NATURE proj:COMPLEX_FUNCTIONALITY ?risks}";


        String queryString2 = "SELECT * WHERE { ?s ?p ?o }";

        Query q = QueryFactory.create(queryString);
        qexeExecution = QueryExecutionFactory.create(q, model);
        rs = qexeExecution.execSelect();
        ResultSetFormatter.out(System.out, rs);
        qexeExecution.close();

        q = QueryFactory.create(queryString2);
        qexeExecution = QueryExecutionFactory.create(q, model);
        rs = qexeExecution.execSelect();
        ResultSetFormatter.out(System.out, rs);

        /*while(rs.hasNext()){
            QuerySolution qSol = rs.nextSolution();
            RDFNode n = qSol.get("risks");
            System.out.println(n);
        }*/

    }finally{
        qexeExecution.close();
    }
}

---

感谢您的帮助。我刚开始学Jena，所以可能我做了一些非常愚蠢的事情。

有个打字错误。前缀以

#

结尾，但在URI中有一个

：

。这是您的前缀声明和URI，已排列好：

prefix proj: http://www.abc123.com/riskmodelling/static/risks#>
             http://www.abc123.com/riskmodelling/static/risks:PROJECT_NATURE
                                                             ^
                                                             |

在您的URI中，它是风险[COLON]项目性质，而不是风险[HASH]项目性质。您需要将前缀更改为：

prefix proj: http://www.abc123.com/riskmodelling/static/risks:>

或者将数据更改为

Resource projectNatureRes = model.createResource(resourceURI+"#PROJECT_NATURE");
// ...and in a few other places, too

---

非常感谢。这是可行的，我没有意识到在查询中必须匹配前缀模式。

prefix proj: http://www.abc123.com/riskmodelling/static/risks#>
             http://www.abc123.com/riskmodelling/static/risks:PROJECT_NATURE
                                                             ^
                                                             |

prefix proj: http://www.abc123.com/riskmodelling/static/risks:>

Resource projectNatureRes = model.createResource(resourceURI+"#PROJECT_NATURE");
// ...and in a few other places, too