Java tutorial
/* Copyright (C) 2003-2011 JabRef contributors. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ package net.sf.jabref.exporter; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.Writer; import java.net.URL; import java.nio.charset.Charset; import java.nio.charset.StandardCharsets; import java.util.List; import java.util.Objects; import java.util.zip.CRC32; import java.util.zip.ZipEntry; import java.util.zip.ZipOutputStream; import javax.xml.transform.OutputKeys; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import net.sf.jabref.BibDatabaseContext; import net.sf.jabref.logic.l10n.Localization; import net.sf.jabref.model.database.BibDatabase; import net.sf.jabref.model.entry.BibEntry; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * @author alver */ public class OpenDocumentSpreadsheetCreator extends ExportFormat { private static final Log LOGGER = LogFactory.getLog(OpenDocumentSpreadsheetCreator.class); /** * Creates a new instance of OpenOfficeDocumentCreator */ public OpenDocumentSpreadsheetCreator() { super(Localization.lang("OpenDocument spreadsheet"), "ods", null, null, ".ods"); } @Override public void performExport(final BibDatabaseContext databaseContext, final String file, final Charset encoding, List<BibEntry> entries) throws Exception { Objects.requireNonNull(databaseContext); Objects.requireNonNull(entries); if (!entries.isEmpty()) { // Only export if entries exists OpenDocumentSpreadsheetCreator.exportOpenDocumentSpreadsheet(new File(file), databaseContext.getDatabase(), entries); } } private static void storeOpenDocumentSpreadsheetFile(File file, InputStream source) throws Exception { try (ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(file)))) { //addResourceFile("mimetype", "/resource/ods/mimetype", out); ZipEntry ze = new ZipEntry("mimetype"); String mime = "application/vnd.oasis.opendocument.spreadsheet"; ze.setMethod(ZipEntry.STORED); ze.setSize(mime.length()); CRC32 crc = new CRC32(); crc.update(mime.getBytes()); ze.setCrc(crc.getValue()); out.putNextEntry(ze); for (int i = 0; i < mime.length(); i++) { out.write(mime.charAt(i)); } out.closeEntry(); ZipEntry zipEntry = new ZipEntry("content.xml"); //zipEntry.setMethod(ZipEntry.DEFLATED); out.putNextEntry(zipEntry); int c; while ((c = source.read()) >= 0) { out.write(c); } out.closeEntry(); // Add manifest (required for OOo 2.0) and "meta.xml": These are in the // resource/ods directory, and are copied verbatim into the zip file. OpenDocumentSpreadsheetCreator.addResourceFile("meta.xml", "/resource/ods/meta.xml", out); OpenDocumentSpreadsheetCreator.addResourceFile("META-INF/manifest.xml", "/resource/ods/manifest.xml", out); } } private static void exportOpenDocumentSpreadsheet(File file, BibDatabase database, List<BibEntry> entries) throws Exception { // First store the xml formatted content to a temporary file. File tmpFile = File.createTempFile("opendocument", null); OpenDocumentSpreadsheetCreator.exportOpenDocumentSpreadsheetXML(tmpFile, database, entries); // Then add the content to the zip file: try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(tmpFile))) { OpenDocumentSpreadsheetCreator.storeOpenDocumentSpreadsheetFile(file, in); } // Delete the temporary file: if (!tmpFile.delete()) { LOGGER.info("Cannot delete temporary export file"); } } private static void exportOpenDocumentSpreadsheetXML(File tmpFile, BibDatabase database, List<BibEntry> entries) { OpenDocumentRepresentation od = new OpenDocumentRepresentation(database, entries); try (Writer ps = new OutputStreamWriter(new FileOutputStream(tmpFile), StandardCharsets.UTF_8)) { DOMSource source = new DOMSource(od.getDOMrepresentation()); StreamResult result = new StreamResult(ps); Transformer trans = TransformerFactory.newInstance().newTransformer(); trans.setOutputProperty(OutputKeys.INDENT, "yes"); trans.transform(source, result); } catch (Exception e) { throw new Error(e); } } private static void addResourceFile(String name, String resource, ZipOutputStream out) throws IOException { ZipEntry zipEntry = new ZipEntry(name); out.putNextEntry(zipEntry); OpenDocumentSpreadsheetCreator.addFromResource(resource, out); out.closeEntry(); } private static void addFromResource(String resource, OutputStream out) { URL url = OpenDocumentSpreadsheetCreator.class.getResource(resource); try (InputStream in = url.openStream()) { byte[] buffer = new byte[256]; synchronized (out) { while (true) { int bytesRead = in.read(buffer); if (bytesRead == -1) { break; } out.write(buffer, 0, bytesRead); } } } catch (IOException e) { LOGGER.warn("Cannot get resource", e); } } }