rdf4j构造查询失败

Question

我正在尝试使用以下代码段通过Wikidata执行构造查询：

construct = "CONSTRUCT { " +
            "   ?s <http://schema.org/about> ?wikipedia ." +
            "} where { " +
            "   OPTIONAL{ " +
            "      ?wikipedia <http://schema.org/about> ?s ; <http://schema.org/inLanguage> ?language ; <http://schema.org/isPartOf> <https://en.wikipedia.org/> . " +
            "   } "+
            "   ?s ?p1 <http://www.wikidata.org/entity/Q12136> . " +
            "}";
            repo = new SPARQLRepository("https://query.wikidata.org/sparql");
            repositoryConnection = repo.getConnection();
            query = repositoryConnection.prepareGraphQuery(construct);
            rs = query.evaluate();
            while (rs.hasNext()) {
                Statement statement = rs.next();
            }

不幸的是，这导致解析错误：

WARN org.eclipse.rdf4j.rio.helpers.ParseErrorLogger - [Rio error] IRI included an unencoded space: '32' (7730, -1)
org.eclipse.rdf4j.query.QueryEvaluationException: org.eclipse.rdf4j.query.QueryEvaluationException: org.eclipse.rdf4j.rio.RDFParseException: IRI included an unencoded space: '32' [line 7730]
    at org.eclipse.rdf4j.query.impl.QueueCursor.convert(QueueCursor.java:58)
    at org.eclipse.rdf4j.query.impl.QueueCursor.convert(QueueCursor.java:22)
    at org.eclipse.rdf4j.common.iteration.QueueIteration.checkException(QueueIteration.java:165)
    at org.eclipse.rdf4j.common.iteration.QueueIteration.getNextElement(QueueIteration.java:134)
    at org.eclipse.rdf4j.common.iteration.LookAheadIteration.lookAhead(LookAheadIteration.java:81)
    at org.eclipse.rdf4j.common.iteration.LookAheadIteration.hasNext(LookAheadIteration.java:49)
    at org.eclipse.rdf4j.common.iteration.IterationWrapper.hasNext(IterationWrapper.java:63)
    at eu.qanswer.mapping.mappings.informa.Refactor.main(Refactor.java:227)

据我在Wikidata中了解，有些uri编码不正确，即存在空格。因此rdf4j解析器抱怨。有没有一种不那么严格的方法来配置解析器？

谢谢D063520

Answer 1

如您所发现，这里的问题是您的查询在服务器端超时。您从RDF4J收到的错误消息令人困惑，但原因是服务器端点无法正确传达存在问题：它只会创建200 HTTP响应（因此RDF4J认为一切正常，并开始处理响应正文）。服务器中途突然将一个错误抛出到响应主体中，这随后使RDF4J解析器抛出此错误。