Question

我试图将RDF / OWL文件上传到我的Sparql端点（由Fuseki提供）。现在我可以上传单个文件，但如果我尝试重复操作，新数据集将覆盖旧数据集。我正在寻找一种方法将数据集中数据的内容与刚刚上传的rdf文件“合并”。有人可以帮帮我吗？感谢。

按照上传/查询端点的代码（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");


    }
}

Answer 1

使用accessor.add(m)代替putModel(m)。正如您在the Javadoc中看到的那样，putModel 替换现有数据。

Jena Fuseki API将新数据添加到现有数据集[java]

1 个答案: