de.catma.document.source.contenthandler.PDFContentHandler.java Source code

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Here is the source code for de.catma.document.source.contenthandler.PDFContentHandler.java

Source

/*
 * CATMA Computer Aided Text Markup and Analysis
 *
 *    Copyright (C) 2008-2010  University Of Hamburg
 *
 *    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 3 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, see <http://www.gnu.org/licenses/>.
 */

package de.catma.document.source.contenthandler;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.util.PDFTextStripper;

/**
 * A content handler for PDF based {@link de.catma.document.source.SourceDocument}s.
 *
 * @author marco.petris@web.de
 *
 */
public class PDFContentHandler extends AbstractSourceContentHandler {

    /* (non-Javadoc)
     * @see de.catma.document.source.contenthandler.SourceContentHandler#load(java.io.InputStream)
     */
    public void load(InputStream is) throws IOException {
        PDDocument document = null;
        try {
            document = PDDocument.load(is, false);

            if (document.isEncrypted()) {
                throw new IOException("can not open pdf document because it is encrypted");
            }

            AccessPermission ap = document.getCurrentAccessPermission();
            if (!ap.canExtractContent()) {
                throw new IOException("You do not have permission to extract text");
            }

            PDFTextStripper stripper = new PDFTextStripper("UTF-8");

            stripper.setForceParsing(false);
            stripper.setSortByPosition(false);
            stripper.setShouldSeparateByBeads(true);
            stripper.setStartPage(1);
            stripper.setEndPage(Integer.MAX_VALUE);

            ByteArrayOutputStream os = new ByteArrayOutputStream();
            Writer w = new OutputStreamWriter(os);
            try {
                stripper.writeText(document, w);
            } finally {
                w.close();
            }
            // some pdfs seem to include non valid unicode characters
            // and this causes problems when converting text to HTML
            // for GUI delivery and during indexing 
            setContent(os.toString().replaceAll("[^\\x09\\x0A\\x0D\\x20-\\uD7FF\\uE000-\\uFFFD\\u10000-\\u10FFFF]",
                    "?"));
        } finally {
            if (document != null) {
                document.close();
            }
        }
    }

    /* (non-Javadoc)
     * @see de.catma.document.source.contenthandler.SourceContentHandler#load()
     */
    public void load() throws IOException {

        try {
            InputStream is = getSourceDocumentInfo().getTechInfoSet().getURI().toURL().openStream();
            try {
                load(is);
            } finally {
                is.close();
            }
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

}