我尝试使用SPARQL CONSTRUCT功能执行以下java代码以创建新的三元组。
package jenasemweb;
import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QueryFactory;
import com.hp.hpl.jena.query.QuerySolution;
import com.hp.hpl.jena.query.ResultSet;
import com.hp.hpl.jena.rdf.model.InfModel;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.Property;
import com.hp.hpl.jena.rdf.model.Resource;
import com.hp.hpl.jena.rdf.model.Statement;
import com.hp.hpl.jena.rdf.model.StmtIterator;
import com.hp.hpl.jena.util.FileManager;
import com.hp.hpl.jena.util.PrintUtil;
public class SparqlQuery03 {
public static void main(String [] args) {
// LOAD Raw Model from URL
Model myRawModel =
FileManager.get().loadModel(
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/Houghland.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/cruz.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/abraham.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/akundi.v2.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/bennett.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/hanna.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/liew_hw2.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/ramani.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/rawal.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/sison.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/tara.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/turney.n3", "N3");
// READ another N3 into the Model
FileManager.get().readModel(myRawModel,
"http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/wilson.n3", "N3");
// Create an RDFS inference model from the Raw Model
InfModel infmodel = ModelFactory.createRDFSModel(myRawModel);
// Create a new SPARQL query
String queryString =
"PREFIX drc: <http://www.codesupreme.com/onto/cse7392/#> " +
"PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> " +
"PREFIX foaf: <http://xmlns.com/foaf/0.1/> " +
"SELECT DISTINCT ?lname ?fname " + // space after last ?var
"WHERE {" +
" ?who foaf:lastName ?lname." +
" ?who foaf:firstName ?fname." +
" }" +
"ORDER BY ?lname";
// create a Jena query from the queryString
com.hp.hpl.jena.query.Query query = QueryFactory.create(queryString);
// create a Jena QueryExecution object that knows the query
// and the N3 over which the query will be run
QueryExecution qe = QueryExecutionFactory.create(query, infmodel);
// execute the query - get back a ResultSet
ResultSet results = qe.execSelect();
// iterate over the result set
while(results.hasNext()) {
QuerySolution sol = results.next();
System.out.println("Solution:" + sol.toString() );
}}}
但执行会返回以下错误:
Exception in thread "main" org.apache.jena.riot.RiotException: [line: 119, col: 27] Unrecognized: [DOT]
at org.apache.jena.riot.system.ErrorHandlerFactory$ErrorHandlerStd.fatal(ErrorHandlerFactory.java:136)
at org.apache.jena.riot.lang.LangEngine.raiseException(LangEngine.java:163)
at org.apache.jena.riot.lang.LangEngine.exceptionDirect(LangEngine.java:156)
at org.apache.jena.riot.lang.LangEngine.exception(LangEngine.java:149)
at org.apache.jena.riot.lang.LangTurtleBase.triplesNodeCompound(LangTurtleBase.java:408)
at org.apache.jena.riot.lang.LangTurtleBase.triplesNode(LangTurtleBase.java:388)
at org.apache.jena.riot.lang.LangTurtleBase.objectList(LangTurtleBase.java:350)
at org.apache.jena.riot.lang.LangTurtleBase.predicateObjectItem(LangTurtleBase.java:288)
at org.apache.jena.riot.lang.LangTurtleBase.predicateObjectList(LangTurtleBase.java:269)
at org.apache.jena.riot.lang.LangTurtleBase.triples(LangTurtleBase.java:250)
at org.apache.jena.riot.lang.LangTurtleBase.triplesSameSubject(LangTurtleBase.java:191)
at org.apache.jena.riot.lang.LangTurtle.oneTopLevelElement(LangTurtle.java:44)
at org.apache.jena.riot.lang.LangTurtleBase.runParser(LangTurtleBase.java:90)
at org.apache.jena.riot.lang.LangBase.parse(LangBase.java:42)
at org.apache.jena.riot.RDFParserRegistry$ReaderRIOTFactoryImpl$1.read(RDFParserRegistry.java:142)
at org.apache.jena.riot.RDFDataMgr.process(RDFDataMgr.java:859)
at org.apache.jena.riot.RDFDataMgr.parse(RDFDataMgr.java:687)
at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:208)
at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:141)
at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:130)
at org.apache.jena.riot.adapters.AdapterFileManager.readModelWorker(AdapterFileManager.java:291)
at com.hp.hpl.jena.util.FileManager.readModel(FileManager.java:369)
at jenasemweb.SparqlQuery03.main(SparqlQuery03.java:44)
我是新手,非常新。所以所有的帮助都表示赞赏。
答案 0 :(得分:1)
该错误与您的SPARQL查询无关。这是关于解析文件http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/hanna.n3
的问题(至少在您提供的代码段中的44
行上)。
我试图运行该文件,并且我在第36行(而不是44)上获得例外,即http://lyle.smu.edu/~coyle/cse7392.semweb/onto/a3/akundi.v2.n3
这可能是一个以点结尾的URI的问题,可能是在三元组的对象中。您是否有可能使用Jena 2.11.0或更早版本?
请参阅https://issues.apache.org/jira/browse/JENA-584 - &gt;你可以尝试升级到Jena 2.11.1。