org.nuxeo.pdf.PDFMerge.java Source code

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Here is the source code for org.nuxeo.pdf.PDFMerge.java

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/*
 * (C) Copyright 2014 Nuxeo SA (http://nuxeo.com/) and contributors.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public License
 * (LGPL) version 2.1 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl-2.1.html
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * Contributors:
 *     Thibaud Arguillere
 */
package org.nuxeo.pdf;

import java.io.File;
import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pdfbox.exceptions.COSVisitorException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.util.PDFMergerUtility;
import org.nuxeo.ecm.automation.core.util.BlobList;
import org.nuxeo.ecm.core.api.Blob;
import org.nuxeo.ecm.core.api.CoreSession;
import org.nuxeo.ecm.core.api.DocumentModel;
import org.nuxeo.ecm.core.api.DocumentModelList;
import org.nuxeo.ecm.core.api.IdRef;
import org.nuxeo.ecm.core.api.impl.blob.FileBlob;
import org.nuxeo.runtime.api.Framework;

/**
 * Merge several PDFs in one.
 * <p>
 * Basically, the caller adds blobs and then <code>merge()</code>. The PDFs are
 * merged in the order they were added.
 * <p>
 * The class accepts misc. parameters: Single <code>Blob</code>,
 * <code>BlobList</code>, single <code>DocumentModel</code>,
 * <code>DocumentModelList</code> or a list of IDs of <code>DocumentModel</code>
 * <p>
 * <i>Notice/i>: These are nuxeo <code>Blob</code>, <code>BlobList</code>, etc.
 * <p>
 * When a <code>DocumentModel</code> is used, the code may expect an xpath to
 * extract the blob form the document. When the xpath parameter is not used (
 * <code>null</code> or ""), the default <code>file:content</code> xpath is
 * used.
 * <p>
 * <p>
 * To let the caller be generic, it's ok to pass a null blob, it is just
 * ignored.
 *
 * @since 5.9.6
 */
public class PDFMerge {

    public static final Log log = LogFactory.getLog(PDFMerge.class);

    protected BlobList blobs = new BlobList();

    public PDFMerge() {

    }

    public PDFMerge(Blob inBlob) {
        addBlob(inBlob);
    }

    public PDFMerge(BlobList inBlobs) {
        addBlobs(inBlobs);
    }

    public PDFMerge(DocumentModel inDoc, String inXPath) {
        addBlob(inDoc, inXPath);
    }

    public PDFMerge(DocumentModelList inDocs, String inXPath) {
        addBlobs(inDocs, inXPath);
    }

    // The original usecase actually :-)
    public PDFMerge(String[] inDocIDs, String inXPath, CoreSession inSession) {
        addBlobs(inDocIDs, inXPath, inSession);
    }

    public void addBlob(Blob inBlob) {
        if (inBlob != null) {
            blobs.add(inBlob);
        }
    }

    public void addBlobs(BlobList inBlobs) {
        for (Blob b : inBlobs) {
            addBlob(b);
        }
    }

    public void addBlob(DocumentModel inDoc, String inXPath) {

        if (inXPath == null || inXPath.isEmpty()) {
            inXPath = "file:content";
        }
        addBlob((Blob) inDoc.getPropertyValue(inXPath));
    }

    public void addBlobs(DocumentModelList inDocs, String inXPath) {

        for (DocumentModel doc : inDocs) {
            addBlob(doc, inXPath);
        }
    }

    public void addBlobs(String[] inDocIDs, String inXPath, CoreSession inSession) {
        for (String id : inDocIDs) {
            DocumentModel doc = inSession.getDocument(new IdRef(id));
            addBlob(doc, inXPath);
        }
    }

    /**
     * Merge the PDFs.
     *
     * @param inFileName
     * @return the Blob embedding the PDF resulting form the merge.
     * @throws COSVisitorException
     * @throws IOException
     *
     * @since 5.9.5
     */
    public Blob merge(String inFileName) throws COSVisitorException, IOException {
        return merge(inFileName, null, null, null);
    }

    /**
     * Merge the PDFs. optionnaly, can set the title, subject and author of the
     * resulting PDF.
     * <p>
     * <b>Notice</b> for title, author and subject: If the value is null or "",
     * it is just ignored
     *
     * @param inFileName
     * @param inTitle
     * @param inSubject
     * @param inAuthor
     * @return
     * @throws IOException
     * @throws COSVisitorException
     *
     * @since 5.9.5
     */
    public Blob merge(String inFileName, String inTitle, String inSubject, String inAuthor)
            throws IOException, COSVisitorException {

        Blob finalBlob = null;

        switch (blobs.size()) {
        case 0:
            finalBlob = null;
            break;

        case 1:
            finalBlob = blobs.get(0);
            break;

        default:
            PDFMergerUtility ut = new PDFMergerUtility();
            for (Blob b : blobs) {
                ut.addSource(b.getStream());
            }

            File tempFile = File.createTempFile("mergepdf", ".pdf");
            ut.setDestinationFileName(tempFile.getAbsolutePath());

            ut.mergeDocuments();

            if (inTitle != null || inAuthor != null || inSubject != null) {
                PDDocument finalDoc = PDDocument.load(tempFile);
                PDFUtils.setInfos(finalDoc, inTitle, inSubject, inAuthor);
                finalDoc.save(tempFile);
                finalDoc.close();
            }

            finalBlob = new FileBlob(tempFile);
            Framework.trackFile(tempFile, finalBlob);

            if (inFileName != null && !inFileName.isEmpty()) {
                finalBlob.setFilename(inFileName);
            } else {
                finalBlob.setFilename(blobs.get(0).getFilename());
            }
            finalBlob.setMimeType("application/pdf");
            break;

        }

        return finalBlob;
    }
}