/*
 * $Id$
 */

/*

 Copyright (c) 2000-2016 Board of Trustees of Leland Stanford Jr. University,
 all rights reserved.

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 STANFORD UNIVERSITY BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
 IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 Except as contained in this notice, the name of Stanford University shall not
 be used in advertising or otherwise to promote the sale, use or other dealings
 in this Software without prior written authorization from Stanford University.

 */

package org.lockss.plugin.highwire;

import org.lockss.filter.pdf.ExtractingPdfFilterFactory;
import org.lockss.pdf.*;
import org.lockss.plugin.ArchivalUnit;
import org.lockss.util.Logger;


/**
 * A pdf filter that handles the more challenging PDFs of child plugins where pdfplus
 * files have non-substantive changes (annotation uris, ordering, etc). In this
 * case scrape out the content text for comparison.
 * This code modified from BaseAtyponScrapingPdfFilterFactory  @author alexohlson
 *
 */
public class HighWireDrupalScrapingPdfFilterFactory extends ExtractingPdfFilterFactory {
  
  private static final Logger log = Logger.getLogger(HighWireDrupalScrapingPdfFilterFactory.class);
  
  /*
   * Many pdf files have the CreationDate and ModDate and the two ID numbers in the trailer
   * vary from collection to collection. Filter them out to avoid incorrect hash failures.
   * This is a scraping filter to it also returns just the actual pdf content and not the layout.
   */
  @Override
  public void transform(ArchivalUnit au, PdfDocument pdfDocument) 
      throws PdfException {
    
    pdfDocument.unsetCreationDate();
    pdfDocument.unsetModificationDate();
    pdfDocument.unsetMetadata();
    pdfDocument.unsetCreator();
    pdfDocument.unsetProducer();
    pdfDocument.unsetAuthor();
    pdfDocument.unsetTitle();
    pdfDocument.unsetSubject();
    pdfDocument.unsetKeywords();
    PdfUtil.normalizeTrailerId(pdfDocument);
    PdfUtil.normalizeAllTokenStreams(pdfDocument);
  }
}


Use Drupal PDF hash filter
Use Drupal PDF hash filter