แก้ไขไฟล์ PDF โดยใช้ Java

Document pdfDocument = new Document("sourceFile.pdf");

Rectangle rect = new Rectangle(200, 500, 300, 600);
RedactionAnnotation annot = new RedactionAnnotation(pdfDocument.getPages().get_Item(1), rect);

annot.setFillColor(Color.getBlack());
annot.setBorderColor(Color.getYellow());
annot.setColor(Color.getBlue());
annot.setFontSize(20);
annot.setOverlayText("REDACTED");
annot.setTextAlignment(HorizontalAlignment.Center);
annot.setRepeat(true);

pdfDocument.getPages().get_Item(1).getAnnotations().add(annot);
pdfDocument.save("output.pdf");
pdfDocument.close();