de.uzk.hki.da.format.PdfService.java Source code

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Here is the source code for de.uzk.hki.da.format.PdfService.java

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package de.uzk.hki.da.format;

/*
 DA-NRW Software Suite | ContentBroker
 Copyright (C) 2013 Historisch-Kulturwissenschaftliche Informationsverarbeitung
 Universitt zu Kln
    
 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/>.
 */

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

import javax.activation.FileDataSource;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.preflight.PreflightDocument;
import org.apache.pdfbox.preflight.ValidationResult;
import org.apache.pdfbox.preflight.ValidationResult.ValidationError;
import org.apache.pdfbox.preflight.parser.PreflightParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Adds PDF Functions of Apache PDFBox to DA-NRW.
 * 
 * @author Jens Peters
 * @author Sebastian Cuy
 */

public class PdfService {

    /** The src pdf file. */
    File srcPdfFile;

    /** The target pdf file. */
    File targetPdfFile;

    /** The logger. */
    private static Logger logger = LoggerFactory.getLogger(PdfService.class);

    /**
     * Instantiates a new pdf service.
     *
     * @param srcPdf the src pdf
     * @param targetPdf the target pdf
     */
    public PdfService(File srcPdf, File targetPdf) {
        this.srcPdfFile = srcPdf;
        this.targetPdfFile = targetPdf;
    }

    /**
     * Instantiates a new pdf service.
     */
    public PdfService() {

    }

    /**
     * Generates a new PDF which only contains certainPages of the original document.
     * Users can choose if they wish to reduce to a number of pages (beginning from the first page)
     * or to a certain set of pages. Both options can be used at the same time. 
     * By setting one of the parameters to either "" or null any of the options the according 
     * option will not be used.
     *
     * @param numberOfPagesText null or empty if unused or "n" (e.g. "2" for two pages from the beginning of the document).
     * @param certainPagesText white space separated list of numbers that mark pages which should be part of the target document.
     * 
     * @throws IOException 
     * @author Jens Peters
     * @author Sebastian Cuy
     * @author Daniel M. de Oliveira
     */
    public void reduceToCertainPages(String numberOfPagesText, String certainPagesText) throws IOException {

        PDDocument srcPdf = null;
        PDDocument targetPdf = null;
        if (srcPdfFile == null)
            throw new IllegalStateException("srcFile not set");

        srcPdf = PDDocument.load(srcPdfFile);
        targetPdf = new PDDocument();

        @SuppressWarnings("rawtypes")
        List srcPages = srcPdf.getDocumentCatalog().getAllPages();

        int numberOfPages = 0;
        if (numberOfPagesText != null && !numberOfPagesText.isEmpty()) {
            numberOfPages = Integer.parseInt(numberOfPagesText);
            for (int i = 0; i < Math.min(numberOfPages, srcPages.size()); i++)
                targetPdf.addPage((PDPage) srcPages.get(i));
        }

        if (certainPagesText != null && !certainPagesText.isEmpty()) {
            String[] certainPagesTexts = certainPagesText.split(" ");
            int[] certainPages = new int[certainPagesTexts.length];
            for (int i = 0; i < certainPagesTexts.length; i++) {
                certainPages[i] = Integer.parseInt(certainPagesTexts[i]);
            }
            Arrays.sort(certainPages);
            for (int i = 0; i < certainPages.length; i++) {
                if (certainPages[i] > numberOfPages && srcPages.size() > certainPages[i] - 1)
                    targetPdf.addPage((PDPage) srcPages.get(certainPages[i] - 1));
            }
        }

        try {
            targetPdf.save(targetPdfFile);
        } catch (Exception e) {
            throw new RuntimeException("Unable to create PDF!", e);
        } finally {
            targetPdf.close();
        }

    }

    /**
     * The Apache Preflight library is a Java tool that implements a parser
     * compliant with the ISO-19005 specification (aka PDF/A-1). Check
     * Compliance with PDF/A-1b
     *
     * @param file the file
     * @return true, if successful
     * @Author: Jens Peters
     */

    public static boolean validatePdfA(File file) {

        ValidationResult result = null;
        try {

            FileDataSource fd = new FileDataSource(file);
            PreflightParser parser;
            parser = new PreflightParser(fd);
            parser.parse();
            PreflightDocument document = parser.getPreflightDocument();
            document.validate();
            result = document.getResult();
            document.close();
        } catch (Exception e) {
            logger.error("Exception validating PDF/A compliance for " + file + " " + e.getCause());
            return false;
        }
        if (result.isValid()) {
            logger.info("The file " + file + " is a valid PDF/A-1b file");
            return true;
        } else {
            logger.info("The file" + file + " is not a valid PDF/A-1b, error(s) :");
            for (ValidationError error : result.getErrorsList()) {
                logger.info(error.getErrorCode() + " : " + error.getDetails());
            }
        }
        return false;
    }

}