overlay
Overlays overlayPdf onto pdf (the overlay drawn in front of each page's existing content) via PdfBox's Overlay.
The overlay's first page is reused for every input page (the common "stamp a letterhead / background frame onto each page" case), so a single-page overlay applies uniformly to a multi-page base document.
Return
the overlaid PDF bytes.
Parameters
pdf
the base PDF bytes.
overlayPdf
the PDF whose first page is stamped over each base page.