org.ghost4j.document.PDFDocument.java Source code

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Here is the source code for org.ghost4j.document.PDFDocument.java

Source

/*
 * Ghost4J: a Java wrapper for Ghostscript API.
 *
 * Distributable under LGPL license.
 * See terms of license at http://www.gnu.org/licenses/lgpl.html.
 */

package org.ghost4j.document;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.io.IOUtils;

import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfCopy;
import com.lowagie.text.pdf.PdfImportedPage;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfWriter;

/**
 * 
 * @author ggrousset
 */
public class PDFDocument extends AbstractDocument {

    /**
     * Serial version UID.
     */
    private static final long serialVersionUID = 6331191005700202153L;

    @Override
    public void load(InputStream inputStream) throws IOException {
        super.load(inputStream);

        // check that the file is a PDF
        ByteArrayInputStream bais = null;
        PdfReader reader = null;

        try {

            bais = new ByteArrayInputStream(content);
            reader = new PdfReader(bais);

        } catch (Exception e) {
            throw new IOException("PDF document is not valid");
        } finally {
            if (reader != null)
                reader.close();
            IOUtils.closeQuietly(bais);
        }
    }

    public int getPageCount() throws DocumentException {

        int pageCount = 0;

        if (content == null) {
            return pageCount;
        }

        ByteArrayInputStream bais = null;
        PdfReader reader = null;

        try {

            bais = new ByteArrayInputStream(content);
            reader = new PdfReader(bais);
            pageCount = reader.getNumberOfPages();

        } catch (Exception e) {
            throw new DocumentException(e);
        } finally {
            if (reader != null)
                reader.close();
            IOUtils.closeQuietly(bais);
        }

        return pageCount;

    }

    public Document extract(int begin, int end) throws DocumentException {

        this.assertValidPageRange(begin, end);

        PDFDocument result = new PDFDocument();

        ByteArrayInputStream bais = null;
        ByteArrayOutputStream baos = null;

        if (content != null) {

            com.lowagie.text.Document document = new com.lowagie.text.Document();

            try {

                bais = new ByteArrayInputStream(content);
                baos = new ByteArrayOutputStream();

                PdfReader inputPDF = new PdfReader(bais);

                // create a writer for the outputstream
                PdfWriter writer = PdfWriter.getInstance(document, baos);

                document.open();
                PdfContentByte cb = writer.getDirectContent();

                PdfImportedPage page;

                while (begin <= end) {
                    document.newPage();
                    page = writer.getImportedPage(inputPDF, begin);
                    cb.addTemplate(page, 0, 0);
                    begin++;
                }

                document.close();

                result.load(new ByteArrayInputStream(baos.toByteArray()));

            } catch (Exception e) {
                throw new DocumentException(e);
            } finally {
                if (document.isOpen())
                    document.close();
                IOUtils.closeQuietly(bais);
                IOUtils.closeQuietly(baos);
            }

        }

        return result;
    }

    @Override
    public void append(Document document) throws DocumentException {

        super.append(document);

        ByteArrayOutputStream baos = null;
        com.lowagie.text.Document mergedDocument = new com.lowagie.text.Document();

        try {

            baos = new ByteArrayOutputStream();
            PdfCopy copy = new PdfCopy(mergedDocument, baos);

            mergedDocument.open();

            // copy current document
            PdfReader reader = new PdfReader(content);
            int pageCount = reader.getNumberOfPages();
            for (int i = 0; i < pageCount;) {
                copy.addPage(copy.getImportedPage(reader, ++i));
            }

            // copy new document
            reader = new PdfReader(document.getContent());
            pageCount = reader.getNumberOfPages();
            for (int i = 0; i < pageCount;) {
                copy.addPage(copy.getImportedPage(reader, ++i));
            }

            mergedDocument.close();

            // replace content with new content
            content = baos.toByteArray();

        } catch (Exception e) {
            throw new DocumentException(e);
        } finally {
            if (mergedDocument.isOpen())
                mergedDocument.close();
            IOUtils.closeQuietly(baos);
        }

    }

    public String getType() {
        return TYPE_PDF;
    }
}