MsOffice2007TextExtractor.java

/**
 *  OpenKM, Open Document Management System (http://www.openkm.com)
 *  Copyright (c) 2006-2011  Paco Avila & Josep Llort
 *
 *  No bytes were intentionally harmed during the development of this application.
 *
 *  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 com.openkm.extractor;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.apache.jackrabbit.extractor.AbstractTextExtractor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;

/**
 * Text extractor for MS Office 2007 documents.
 */
public class MsOffice2007TextExtractor extends AbstractTextExtractor {

    /**
     * Logger instance.
     */
    private static final Logger log = LoggerFactory.getLogger(MsOffice2007TextExtractor.class);

    /**
     * Creates a new <code>MsOffice2007TextExtractor</code> instance.
     */
    public MsOffice2007TextExtractor() {
        super(new String[]{"application/vnd.openxmlformats-officedocument.wordprocessingml.document",
                           "application/vnd.openxmlformats-officedocument.wordprocessingml.template",
                           "application/vnd.openxmlformats-officedocument.presentationml.template",
                           "application/vnd.openxmlformats-officedocument.presentationml.slideshow",
                           "application/vnd.openxmlformats-officedocument.presentationml.presentation",
                           "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                           "application/vnd.openxmlformats-officedocument.spreadsheetml.template"});
    }
    
    //-------------------------------------------------------< TextExtractor >

    /**
     * {@inheritDoc}
     */ 
    public Reader extractText(InputStream stream, String type, String encoding) throws IOException {
    	ZipInputStream zis = null;
    	
        try {
        	SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
            saxParserFactory.setValidating(false);
            SAXParser saxParser = saxParserFactory.newSAXParser();
            XMLReader xmlReader = saxParser.getXMLReader();
            xmlReader.setFeature("http://xml.org/sax/features/validation", false);
            xmlReader.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
            MsOffice2007ContentHandler contentHandler = null;
            
            if (type.equals("application/vnd.openxmlformats-officedocument.wordprocessingml.document") ||
            		type.equals("application/vnd.openxmlformats-officedocument.wordprocessingml.template")) {
            	contentHandler = new WordprocessingMLContentHandler();
            } else if (type.equals("application/vnd.openxmlformats-officedocument.presentationml.template") ||
            		type.equals("application/vnd.openxmlformats-officedocument.presentationml.slideshow") ||
            		type.equals("application/vnd.openxmlformats-officedocument.presentationml.presentation")) {
            	contentHandler = new PresentationMLContentHandler();
            } else if (type.equals("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet") ||
            		type.equals("application/vnd.openxmlformats-officedocument.spreadsheetml.template")) {
            	contentHandler = new SpreadsheetMLContentHandler();
            }

            xmlReader.setContentHandler(contentHandler);
            zis = new ZipInputStream(stream);
            ZipEntry ze;
            StringBuffer sb = new StringBuffer();
            
            while ((ze = zis.getNextEntry()) != null) {
            	if (ze.getName().startsWith(contentHandler.getFilePattern())) {
            		// It is unspecified whether the XML parser closes the stream when
                    // done parsing. To ensure that the stream gets closed just once,
                    // we prevent the parser from closing it by catching the close()
                    // call and explicitly close the stream in a finally block.
                    InputSource is = new InputSource(new FilterInputStream(zis) {
                        public void close() {}
                    });
                
                    log.debug("Parsing "+ze);
                    xmlReader.parse(is);
                    sb.append(contentHandler.getContent());
            	} else {
            		log.debug("- "+ze);
            	}
            }
           
            log.debug("TEXT: "+sb.toString());
            return new StringReader(sb.toString());
        } catch (ParserConfigurationException e) {
            log.warn("Failed to extract Microsoft Office 2007 text content", e);
            return new StringReader("");
        } catch (SAXException e) {
            log.warn("Failed to extract Microsoft Office 2007 text content", e);
            return new StringReader("");
        } finally {
			zis.close();
			stream.close();
        }
    }
}