366 Watermark on Document
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Watermark on Document

Stamp text such as DRAFT, COPY, PAID or CONFIDENTIAL on every page of an existing PDF - one from this lab or your own upload. New documents can also get a watermark from their page setup preset (Page Setup Studio).

Colour
Layer
How it works
  • PdfReader opens the existing PDF, PdfStamper writes a copy with extra content on each page.
  • getOverContent(page) draws on top of the text; getUnderContent(page) draws behind it (hidden by solid backgrounds such as table headers).
  • Transparency needs a graphics state: PdfGState.setFillOpacity(0.2f).
  • The diagonal angle is atan2(pageHeight, pageWidth), so the text runs corner to corner on any paper size.
PdfStamper stamper = new PdfStamper(new PdfReader(pdf), out);
PdfGState gs = new PdfGState();
gs.setFillOpacity(0.20f);
for (int i = 1; i <= reader.getNumberOfPages(); i++) {
    PdfContentByte cb = stamper.getOverContent(i);
    cb.saveState();
    cb.setGState(gs);
    cb.beginText();
    cb.setFontAndSize(bold, 80);
    cb.showTextAligned(Element.ALIGN_CENTER, "CONFIDENTIAL", centreX, centreY, 54.7f);
    cb.endText();
    cb.restoreState();
}
stamper.close();

Files: service/WatermarkService.java (existing PDFs), print/PageDecorator.drawWatermark (new PDFs).