hu.bme.mit.trainbenchmark.generator.rdf.RdfSerializer.java Source code

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Here is the source code for hu.bme.mit.trainbenchmark.generator.rdf.RdfSerializer.java

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/*******************************************************************************
 * Copyright (c) 2010-2015, Benedek Izso, Gabor Szarnyas, Istvan Rath and Daniel Varro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Benedek Izso - initial API and implementation
 *   Gabor Szarnyas - initial API and implementation
 *******************************************************************************/

package hu.bme.mit.trainbenchmark.generator.rdf;

import static hu.bme.mit.trainbenchmark.rdf.RdfConstants.ID_PREFIX;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.commons.io.FileUtils;

import hu.bme.mit.trainbenchmark.constants.ModelConstants;
import hu.bme.mit.trainbenchmark.generator.ModelSerializer;
import hu.bme.mit.trainbenchmark.generator.rdf.config.RdfGeneratorConfig;
import hu.bme.mit.trainbenchmark.rdf.RdfHelper;

public class RdfSerializer extends ModelSerializer<RdfGeneratorConfig> {

    protected BufferedWriter file;
    protected String RDF_METAMODEL_DIR = "/trainbenchmark-format-rdf/src/main/resources/metamodel/";

    public RdfSerializer(final RdfGeneratorConfig generatorConfig) {
        super(generatorConfig);
    }

    @Override
    public String syntax() {
        return "RDF" + gc.getModelFlavor();
    }

    @Override
    public void initModel() throws IOException {
        // source file
        final String modelFlavor = gc.getModelFlavor();
        final String extension = gc.getExtension();

        final String postfix = modelFlavor + "." + extension;

        final String srcFilePath = gc.getConfigBase().getWorkspaceDir() + RDF_METAMODEL_DIR + "railway" + postfix;

        final File srcFile = new File(srcFilePath);

        // destination file
        final String destFilePath = gc.getConfigBase().getModelPathWithoutExtension() + postfix;
        final File destFile = new File(destFilePath);

        // this overwrites the destination file if it exists
        FileUtils.copyFile(srcFile, destFile);

        file = new BufferedWriter(new FileWriter(destFile, true));
    }

    @Override
    public void persistModel() throws IOException {
        file.close();
    }

    @Override
    public Object createVertex(final int id, final String type, final Map<String, ? extends Object> attributes,
            final Map<String, Object> outgoingEdges, final Map<String, Object> incomingEdges) throws IOException {

        // vertex id and type
        final String triple = String.format(":%s%d a :%s", ID_PREFIX, id, type);
        final StringBuilder vertex = new StringBuilder(triple);

        final String linePrefix;

        switch (gc.getFormat()) {
        case NTRIPLES:
            linePrefix = String.format(" .\n:%s%d ", ID_PREFIX, id);
            break;
        case TURTLE:
            linePrefix = " ;\n\t";
            break;
        default:
            throw new UnsupportedOperationException("RDF format " + gc.getFormat() + " not supported");
        }

        // if the metamodel is not included, we manually insert the inferenced triples
        if (gc.isInferred()) {
            if (ModelConstants.SUPERTYPES.containsKey(type)) {
                final String superType = ModelConstants.SUPERTYPES.get(type);

                final String superTypeTriple = String.format("%sa :%s", linePrefix, superType);
                vertex.append(superTypeTriple);
            }
        }

        // (id)-[]->() attributes
        for (final Entry<String, ? extends Object> attribute : attributes.entrySet()) {
            final String attributeTriple = String.format("%s:%s %s", linePrefix, attribute.getKey(),
                    stringValue(attribute.getValue()));
            vertex.append(attributeTriple);
        }

        // (id)-[]->() edges
        for (final Entry<String, Object> outgoingEdge : outgoingEdges.entrySet()) {
            if (outgoingEdge.getValue() == null) {
                continue;
            }

            final String edgeTriple = String.format("%s:%s :%s%s", linePrefix, outgoingEdge.getKey(), ID_PREFIX,
                    outgoingEdge.getValue());
            vertex.append(edgeTriple);
        }

        vertex.append(" .");
        write(vertex.toString());

        // ()-[]->(id) edges
        for (final Entry<String, Object> incomingEdge : incomingEdges.entrySet()) {
            createEdge(incomingEdge.getKey(), incomingEdge.getValue(), id);
        }

        return id;
    }

    @Override
    public void createEdge(final String label, final Object from, final Object to) throws IOException {
        if (from == null || to == null) {
            return;
        }
        final String triple = String.format(":%s%s :%s :%s%s .", ID_PREFIX, from, label, ID_PREFIX, to);
        write(triple);
    }

    @Override
    public void setAttribute(final String type, final Object node, final String key, final Object value)
            throws IOException {
        final String triple = String.format(":%s%s :%s %s", ID_PREFIX, node, key, stringValue(value));
        write(triple + " .");

    }

    protected void write(final String s) throws IOException {
        switch (gc.getFormat()) {
        case NTRIPLES:
            file.write(s + "\n");
            break;
        case TURTLE:
            file.write(s + "\n\n");
            break;
        default:
            throw new UnsupportedOperationException("RDF format " + gc.getFormat() + " not supported");
        }
    }

    protected String stringValue(final Object value) {
        if (value instanceof Boolean) {
            return Boolean.toString((Boolean) value);
        }
        if (value instanceof Integer) {
            return String.format("\"%d\"^^xsd:int", value);
        }
        if (value instanceof Enum<?>) {
            final Enum<?> e = (Enum<?>) value;
            return String.format(":%s", RdfHelper.addEnumPrefix(e));
        } else {
            return value.toString();
        }
    }

}