[英]Jena Fuseki API add new data to an exsisting dataset [java]
我试图将RDF / OWL文件上传到我的Sparql端点(由Fuseki提供)。 现在,我可以上传一个文件,但是如果我尝试重复该操作,则新数据集将覆盖旧文件。 我正在寻找一种方法,用刚刚上传的新rdf文件“合并”数据集中的数据内容。 有人可以帮助我吗? 谢谢。
按照代码上载/查询端点(我不是作者)
// Written in 2015 by Thilo Planz
// To the extent possible under law, I have dedicated all copyright and related and neighboring rights
// to this software to the public domain worldwide. This software is distributed without any warranty.
// http://creativecommons.org/publicdomain/zero/1.0/
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.ByteArrayOutputStream;
import org.apache.jena.query.DatasetAccessor;
import org.apache.jena.query.DatasetAccessorFactory;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QuerySolution;
import org.apache.jena.query.ResultSet;
import org.apache.jena.query.ResultSetFormatter;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.rdf.model.ModelFactory;
import org.apache.jena.rdf.model.RDFNode;
class FusekiExample {
public static void uploadRDF(File rdf, String serviceURI)
throws IOException {
// parse the file
Model m = ModelFactory.createDefaultModel();
try (FileInputStream in = new FileInputStream(rdf)) {
m.read(in, null, "RDF/XML");
}
// upload the resulting model
DatasetAccessor accessor = DatasetAccessorFactory.createHTTP(serviceURI);
accessor.putModel(m);
}
public static void execSelectAndPrint(String serviceURI, String query) {
QueryExecution q = QueryExecutionFactory.sparqlService(serviceURI,
query);
ResultSet results = q.execSelect();
// write to a ByteArrayOutputStream
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
//convert to JSON format
ResultSetFormatter.outputAsJSON(outputStream, results);
//turn json to string
String json = new String(outputStream.toByteArray());
//print json string
System.out.println(json);
}
public static void execSelectAndProcess(String serviceURI, String query) {
QueryExecution q = QueryExecutionFactory.sparqlService(serviceURI,
query);
ResultSet results = q.execSelect();
while (results.hasNext()) {
QuerySolution soln = results.nextSolution();
// assumes that you have an "?x" in your query
RDFNode x = soln.get("x");
System.out.println(x);
}
}
public static void main(String argv[]) throws IOException {
// uploadRDF(new File("test.rdf"), );
uploadRDF(new File("test.rdf"), "http://localhost:3030/MyEndpoint/data");
}
}
使用accessor.add(m)
代替putModel(m)
。 如您在Javadoc中putModel
, putModel
替换了现有数据。
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