PDFlib Cookbook

cookbook

pdf_import/import_in_reverse_order

Read the pages of an input PDF document and output them in reverse order.

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/*
 * Import in reverse order:
 * Read the pages of an input PDF document and output them in reverse order
 *  
 * Open the pages of the input document in reverse order and place them in
 * the output PDF.
 *  
 * Required software: PDFlib+PDI/PPS 9
 * Required data: PDF document
 */
package com.pdflib.cookbook.pdflib.pdf_import;

import com.pdflib.pdflib;
import com.pdflib.PDFlibException;

public class import_in_reverse_order
{
    public static void main (String argv[])
    {
        /* This is where the data files are. Adjust as necessary. */
        String searchpath = "../input";
        String outfile = "import_in_reverse_order.pdf";
        String title = "Import in Reverse Order";

        pdflib p = null;
        String pdffile = "PDFlib-datasheet.pdf";
        int indoc, pageno, endpage, page;
        int exitcode = 0;

        try {
            p = new pdflib();

            p.set_option("searchpath={" + searchpath + "}");

            /* This means we must check return values of load_font() etc. */
            p.set_option("errorpolicy=return");

            if (p.begin_document(outfile, "") == -1)
                throw new Exception("Error: " + p.get_errmsg());

            p.set_info("Creator", "PDFlib Cookbook");
            p.set_info("Title", title);

            /* Open the input PDF */
            indoc = p.open_pdi_document(pdffile, "");
            if (indoc == -1)
                throw new Exception("Error: " + p.get_errmsg());
       
            /* Retrieve the overall number of pages for the input document */
            endpage = (int) p.pcos_get_number(indoc, "length:pages");

            /* Loop over all pages of the input document in reverse order */
            for (pageno = endpage; pageno > 0; pageno--)
            {
                page = p.open_pdi_page(indoc, pageno, "");

                if (page == -1)
                    throw new Exception("Error: " + p.get_errmsg());

                /* Page size may be adjusted by fit_pdi_page(). */
                p.begin_page_ext(0, 0, "width=a4.width height=a4.height");

                /* Place the imported page without performing
                 * any changes on the output page
                 */
                p.fit_pdi_page(page, 0, 0, "adjustpage");
                
                p.end_page_ext("");

                p.close_pdi_page(page);
            }
     
            p.end_document("");

        } catch (PDFlibException e) {
            System.err.println("PDFlib exception occurred:");
            System.err.println("[" + e.get_errnum() + "] " + e.get_apiname()
                + ": " + e.get_errmsg());
            exitcode = 1;
        } catch (Exception e) {
            System.err.println(e);
            exitcode = 1;
        } finally {
            if (p != null) {
                p.delete();
            }
            System.exit(exitcode);
        }
    }
}