org.sejda.impl.itext5.component.PdfUnpacker.java Source code

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Here is the source code for org.sejda.impl.itext5.component.PdfUnpacker.java

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/*
 * Created on 15/gen/2014
 * Copyright 2014 by Andrea Vacondio (andrea.vacondio@gmail.com).
 * This file is part of sejda-itext5.
 *
 * sejda-itext5 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * sejda-itext5 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with sejda-itext5.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.sejda.impl.itext5.component;

import static org.sejda.core.support.io.IOUtils.createTemporaryBuffer;
import static org.sejda.core.support.io.model.FileOutput.file;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Set;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.sejda.common.collection.NullSafeSet;
import org.sejda.core.support.io.MultipleOutputWriter;
import org.sejda.core.support.io.OutputWriters;
import org.sejda.model.exception.TaskException;
import org.sejda.model.exception.TaskIOException;
import org.sejda.model.output.MultipleTaskOutput;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.itextpdf.text.pdf.PRStream;
import com.itextpdf.text.pdf.PdfArray;
import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfNameTree;
import com.itextpdf.text.pdf.PdfObject;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfString;

/**
 * Component responsible for unpacking attachments attached to multiple pdf documents.
 * 
 * @author Andrea Vacondio
 * 
 */
public class PdfUnpacker {

    private static final Logger LOG = LoggerFactory.getLogger(PdfUnpacker.class);

    private MultipleOutputWriter outputWriter;

    public PdfUnpacker(boolean overwrite) {
        outputWriter = OutputWriters.newMultipleOutputWriter(overwrite);
    }

    public void unpack(PdfReader reader) throws TaskException {
        if (reader == null) {
            throw new TaskException("Unable to unpack a null reader.");
        }
        LOG.debug("Unpacking started");
        Set<PdfDictionary> dictionaries = getAttachmentsDictionaries(reader);
        if (dictionaries.isEmpty()) {
            LOG.info("No attachments found.");
        } else {
            unpack(dictionaries);
        }
    }

    private void unpack(Set<PdfDictionary> dictionaries) throws TaskIOException {
        for (PdfDictionary dictionary : dictionaries) {
            PdfName type = dictionary.getAsName(PdfName.TYPE);
            if (PdfName.F.equals(type) || PdfName.FILESPEC.equals(type)) {
                PdfDictionary ef = dictionary.getAsDict(PdfName.EF);
                PdfString fn = dictionary.getAsString(PdfName.F);
                if (fn != null && ef != null) {
                    PRStream prs = (PRStream) PdfReader.getPdfObject(ef.get(PdfName.F));
                    if (prs != null) {
                        File tmpFile = copyToTemporaryFile(prs);
                        outputWriter.addOutput(file(tmpFile).name(fn.toUnicodeString()));
                    }
                }
            }
        }
    }

    private File copyToTemporaryFile(PRStream prs) throws TaskIOException {
        File tmpFile = createTemporaryBuffer();
        LOG.debug("Created output temporary buffer {}", tmpFile);

        ByteArrayInputStream inputStream = null;
        try {
            inputStream = new ByteArrayInputStream(PdfReader.getStreamBytes(prs));
            FileUtils.copyInputStreamToFile(inputStream, tmpFile);
            LOG.debug("Attachment unpacked to temporary buffer");
        } catch (IOException e) {
            throw new TaskIOException("Unable to copy attachment to temporary file.", e);
        } finally {
            IOUtils.closeQuietly(inputStream);
        }
        return tmpFile;
    }

    /**
     * writes to the output
     * 
     * @param output
     * @throws TaskIOException
     */
    public void write(MultipleTaskOutput<?> output) throws TaskException {
        output.accept(outputWriter);
    }

    private Set<PdfDictionary> getAttachmentsDictionaries(PdfReader reader) {
        Set<PdfDictionary> retSet = new NullSafeSet<PdfDictionary>();
        retSet.addAll(getEmbeddedFilesDictionaries(reader));
        retSet.addAll(getFileAttachmentsDictionaries(reader));
        return retSet;
    }

    private Set<PdfDictionary> getEmbeddedFilesDictionaries(PdfReader reader) {
        Set<PdfDictionary> retSet = new NullSafeSet<PdfDictionary>();
        PdfDictionary catalog = reader.getCatalog();
        PdfDictionary names = catalog.getAsDict(PdfName.NAMES);
        if (names != null) {
            PdfDictionary embFiles = names.getAsDict(PdfName.EMBEDDEDFILES);
            if (embFiles != null) {
                HashMap<String, PdfObject> embMap = PdfNameTree.readTree(embFiles);
                for (PdfObject value : embMap.values()) {
                    retSet.add((PdfDictionary) PdfReader.getPdfObject(value));
                }
            }
        }
        return retSet;
    }

    private Set<PdfDictionary> getFileAttachmentsDictionaries(PdfReader reader) {
        Set<PdfDictionary> retSet = new NullSafeSet<PdfDictionary>();
        for (int k = 1; k <= reader.getNumberOfPages(); ++k) {
            PdfArray annots = reader.getPageN(k).getAsArray(PdfName.ANNOTS);
            if (annots != null) {
                for (PdfObject current : annots) {
                    PdfDictionary annot = (PdfDictionary) PdfReader.getPdfObject(current);
                    if (PdfName.FILEATTACHMENT.equals(annot.getAsName(PdfName.SUBTYPE))) {
                        retSet.add(annot.getAsDict(PdfName.FS));
                    }
                }
            }
        }
        return retSet;
    }
}