org.aksw.rdfunit.io.writer.RdfFileWriter Maven / Gradle / Ivy

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package org.aksw.rdfunit.io.writer;

import org.aksw.jena_sparql_api.core.QueryExecutionFactory;
import org.aksw.rdfunit.io.IOUtils;
import org.aksw.rdfunit.services.PrefixNSService;
import org.apache.jena.rdf.model.Model;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;

/**
 * RDFFileWriter class.
 *
 * @author Dimitris Kontokostas
 *         Writes a Model to a file
 * @since 11/14/13 1:01 PM
 * @version $Id: $Id
 */
public class RdfFileWriter implements RdfWriter {
    private final String filename;
    private final String filetype;
    private final boolean skipIfExists;
    private final boolean createParentDirectories;
    private final boolean overwrite;


    /**
     * Constructor for RDFFileWriter.
     *
     * @param filename a {@link java.lang.String} object.
     */
    public RdfFileWriter(String filename) {
        this(filename, "TURTLE", false, true, true);
    }

    /**
     * Constructor for RDFFileWriter.
     *
     * @param filename a {@link java.lang.String} object.
     * @param filetype a {@link java.lang.String} object.
     */
    public RdfFileWriter(String filename, String filetype) {
        this(filename, filetype, false, true, true);
    }

    /**
     * Constructor for RDFFileWriter.
     *
     * @param filename a {@link java.lang.String} object.
     * @param skipIfExists a boolean.
     */
    public RdfFileWriter(String filename, boolean skipIfExists) {
        this(filename, "TURTLE", skipIfExists, true, true);
    }

    /**
     * Constructor for RDFFileWriter.
     *
     * @param filename a {@link java.lang.String} object.
     * @param filetype a {@link java.lang.String} object.
     * @param skipIfExists a boolean.
     * @param createParentDirectories a boolean.
     * @param overwrite a boolean.
     */
    public RdfFileWriter(String filename, String filetype, boolean skipIfExists, boolean createParentDirectories, boolean overwrite) {
        super();
        this.filename = filename;
        this.filetype = filetype;
        this.skipIfExists = skipIfExists;
        this.createParentDirectories = createParentDirectories;
        this.overwrite = overwrite;
    }

    /** {@inheritDoc} */
    @Override
    public void write(QueryExecutionFactory qef) throws RdfWriterException {

        File file = new File(filename);
        if (file.exists() && skipIfExists) {
            return;
        }

        if (file.exists() && !overwrite) {
            throw new RdfWriterException("Error writing file: File already exists and cannot overwrite");
        }


        if (createParentDirectories) {
            File parentF = file.getParentFile();
            if (parentF != null && !parentF.exists() && !parentF.mkdirs()) {
                throw new RdfWriterException("Error writing file: Cannot create new directory structure for file: " + filename);
            }
        }

        try (OutputStream fos = new FileOutputStream(file)) {

            Model model = IOUtils.getModelFromQueryFactory(qef);
            PrefixNSService.setNSPrefixesInModel(model);
            model.write(fos, filetype);

        } catch (Exception e) {
            throw new RdfWriterException("Error writing file: " + e.getMessage(), e);
        }

    }
}