Add Page Numbers to PDF in Java

Add a page number stamp

1. Open the source PDF Document.
2. Create the PageNumberStamp object.
3. Configure the required stamp placement and numbering options.
4. Set the required text formatting options, including FontRepository and Color.
5. Add the configured PageNumberStamp to the target Page.
6. Save the updated PDF Document.

public static void addPageNumStamp(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        PageNumberStamp pageNumberStamp = new PageNumberStamp();
        pageNumberStamp.setBackground(false);
        pageNumberStamp.setFormat("Page # of " + document.getPages().size());
        pageNumberStamp.setBottomMargin(10);
        pageNumberStamp.setHorizontalAlignment(HorizontalAlignment.Center);
        pageNumberStamp.setStartingNumber(1);
        pageNumberStamp.getTextState().setFont(FontRepository.findFont("Arial"));
        pageNumberStamp.getTextState().setFontSize(14.0f);
        pageNumberStamp.getTextState().setFontStyle(FontStyles.Bold | FontStyles.Italic);
        pageNumberStamp.getTextState().setForegroundColor(Color.getBlueViolet());

        document.getPages().get_Item(1).addStamp(pageNumberStamp);
        document.save(outputFile.toString());
    }
}