org.apache.jena.examples.ExampleARQ_06.java Source code

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Here is the source code for org.apache.jena.examples.ExampleARQ_06.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jena.examples;

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;

import org.apache.jena.graph.Node;
import org.apache.jena.query.Query;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QueryFactory;
import org.apache.jena.query.ResultSet;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.sparql.core.Var;
import org.apache.jena.sparql.engine.binding.Binding;
import org.apache.jena.sparql.serializer.SerializationContext;
import org.apache.jena.sparql.util.FmtUtils;
import org.apache.jena.util.FileManager;

public class ExampleARQ_06 {

    public static void main(String[] args) throws IOException {
        FileManager.get().addLocatorClassLoader(ExampleARQ_01.class.getClassLoader());
        Model model = FileManager.get().loadModel("data/data.ttl");
        Query query = QueryFactory.create("SELECT * WHERE { ?s ?p ?o }");
        QueryExecution qexec = QueryExecutionFactory.create(query, model);

        FileOutputStream out = new FileOutputStream("target/sxssf.xlsx");
        Workbook wb = new SXSSFWorkbook(100);
        Sheet sh = wb.createSheet();

        int rows = 0;
        int columns = 0;
        try {
            ResultSet resultSet = qexec.execSelect();
            List<String> varNames = resultSet.getResultVars();
            List<Var> vars = new ArrayList<Var>(varNames.size());

            // first row with var names
            Row row = sh.createRow(rows++);
            for (String varName : varNames) {
                Var var = Var.alloc(varName);
                Cell cell = row.createCell(columns++);
                cell.setCellValue(var.toString());
                vars.add(var);
            }

            // other rows with bindings
            while (resultSet.hasNext()) {
                Binding bindings = resultSet.nextBinding();
                row = sh.createRow(rows++);
                columns = 0;
                for (Var var : vars) {
                    Node n = bindings.get(var);
                    if (n != null) {
                        Cell cell = row.createCell(columns++);
                        String value = FmtUtils.stringForNode(n, (SerializationContext) null);
                        cell.setCellValue(value);
                    }
                }
            }
        } finally {
            qexec.close();
        }

        wb.write(out);
        out.close();
    }

}