[英]Jena Fuseki API add new data to an exsisting dataset [java]
我試圖將RDF / OWL文件上傳到我的Sparql端點(由Fuseki提供)。 現在,我可以上傳一個文件,但是如果我嘗試重復該操作,則新數據集將覆蓋舊文件。 我正在尋找一種方法,用剛剛上傳的新rdf文件“合並”數據集中的數據內容。 有人可以幫助我嗎? 謝謝。
按照代碼上載/查詢端點(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
替換了現有數據。
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