How to reorder the pages of a PDF file?

Question

I am generating Table of Contents at last,I want to move Table of Contents at Beginning. Suppose that I have 16 pages in my PDF and that the TOC starts from page 13 and ends on

Answer 1

You can select the pages readed by PdfReader:

PdfReader sourcePDFReader = new PdfReader(RESULT1);
reader.selectPages("1-13");

Then you can use PdfStamper or PdfCopy to assemble then in order. Please refer to:

Itext Documentation, Related question

Edit: This is a piece of code i use to put a list of pdf together, maybe it's helpful to you. (You could read pages 15-16, save to pdf and then repeat with pages 1-13. Then combine the two resulting pdfs)

private byte[] combinePdf(List archivos) throws DocumentException,
        IOException {
    ByteArrayOutputStream osPdf = new ByteArrayOutputStream();
    com.itextpdf.text.Document document = new com.itextpdf.text.Document();
    PdfWriter writer = PdfWriter.getInstance(document, osPdf);
    document.open();
    PdfContentByte cb = writer.getDirectContent();

    for (byte[] in : archivos) {
        PdfReader reader = new PdfReader(in);
        for (int i = 1; i <= reader.getNumberOfPages(); i++) {
            document.newPage();
            PdfImportedPage page = writer.getImportedPage(reader, i);
            cb.addTemplate(page, 0, 0);
        }
    }
    osPdf.flush();
    document.close();

    return osPdf.toByteArray();
}

Edit 2: as Bruno posted, this is a bad solution because all the pdf links are lost using the document/ pdfWritter combination.