eu.europa.cedefop.europass.jtool.util.ExtractAttachments.java Source code

Introduction

Here is the source code for eu.europa.cedefop.europass.jtool.util.ExtractAttachments.java

Source

package eu.europa.cedefop.europass.jtool.util;

/*
  * Copyright European Union 2002-2010
  *
  *
  * Licensed under the EUPL, Version 1.1 or  as soon they 
  * will be approved by the European Commission - subsequent  
  * versions of the EUPL (the "Licence"); 
  * You may not use this work except in compliance with the 
  * Licence. 
  * You may obtain a copy of the Licence at: 
  *
  * http://ec.europa.eu/idabc/eupl.html
  *
  *  
  * Unless required by applicable law or agreed to in 
  * writing, software distributed under the Licence is 
  * distributed on an "AS IS" basis, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 
  * express or implied. 
  * See the Licence for the specific language governing 
  * permissions and limitations under the Licence. 
  *
  */

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

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import java.util.HashMap;
import java.util.Iterator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * This class extract the attachment files from a PDF file.
 * @author Gomosidis Apostolos, Quality & Reliability S.A.
 * @version %I%, %G%
 * @since 1.0
 */
public class ExtractAttachments {
    private static final Log log = LogFactory.getLog(ExtractAttachments.class);
    private InputStream in;
    private File trgfile = null;

    /**
     * Class constructor
     * @param in the InputStream of the PDF file
     * @param trgfile the extract (XML) file path
     * @throws IOException
     */
    public ExtractAttachments(InputStream in, File trgfile) throws IOException {
        this.in = in;
        this.trgfile = trgfile;
    }

    /**
      * Extract the attachment file
      * @throws Exception
      */
    public void execute() throws Exception {
        boolean hasAttachment = false;
        try {
            PdfReader reader = new PdfReader(in);
            PdfDictionary catalog = reader.getCatalog();
            PdfDictionary names = (PdfDictionary) PdfReader.getPdfObject(catalog.get(PdfName.NAMES));
            if (names != null) {
                PdfDictionary embFiles = (PdfDictionary) PdfReader
                        .getPdfObject(names.get(new PdfName("EmbeddedFiles")));
                if (embFiles != null) {
                    HashMap embMap = PdfNameTree.readTree(embFiles);
                    for (Iterator i = embMap.values().iterator(); i.hasNext();) {
                        PdfDictionary filespec = (PdfDictionary) PdfReader.getPdfObject((PdfObject) i.next());
                        unpackFile(filespec);
                    }
                }
            }
            for (int k = 1; k <= reader.getNumberOfPages(); ++k) {
                PdfArray annots = (PdfArray) PdfReader.getPdfObject(reader.getPageN(k).get(PdfName.ANNOTS));
                if (annots == null)
                    continue;
                for (Iterator i = annots.listIterator(); i.hasNext();) {
                    PdfDictionary annot = (PdfDictionary) PdfReader.getPdfObject((PdfObject) i.next());
                    PdfName subType = (PdfName) PdfReader.getPdfObject(annot.get(PdfName.SUBTYPE));
                    if (!PdfName.FILEATTACHMENT.equals(subType))
                        continue;
                    PdfDictionary filespec = (PdfDictionary) PdfReader.getPdfObject(annot.get(PdfName.FS));
                    hasAttachment = true;
                    unpackFile(filespec);
                }
            }
        } catch (Exception e) {
            log.error("Error while extracting PDF attachements: " + e);
        }
        if (!hasAttachment)
            throw new Exception("PDF file does not have attachment.");
    }

    /**
    * Get the attachment file     
    * @param filespec 
    * @throws IOException
    */
    public void unpackFile(PdfDictionary filespec) throws IOException {
        if (filespec == null)
            return;

        PdfName type = (PdfName) PdfReader.getPdfObject(filespec.get(PdfName.TYPE));
        if (!PdfName.F.equals(type) && !PdfName.FILESPEC.equals(type))
            return;

        PdfDictionary ef = (PdfDictionary) PdfReader.getPdfObject(filespec.get(PdfName.EF));
        if (ef == null)
            return;

        PdfString fn = (PdfString) PdfReader.getPdfObject(filespec.get(PdfName.F));
        if (fn == null)
            return;

        PRStream prs = (PRStream) PdfReader.getPdfObject(ef.get(PdfName.F));
        if (prs == null)
            return;
        byte b[] = PdfReader.getStreamBytes(prs);
        FileOutputStream fout = new FileOutputStream(trgfile);
        fout.write(b);
        fout.close();
    }

}