public static PdfStamper createSignature(
PdfReader reader, OutputStream os, char pdfVersion, File tempFile, boolean append)
throws DocumentException, IOException {
PdfStamper stp;
if (tempFile == null) {
ByteBuffer bout = new ByteBuffer();
stp = new PdfStamper(reader, bout, pdfVersion, append);
stp.sigApp = new PdfSignatureAppearance(stp.stamper);
stp.sigApp.setSigout(bout);
} else {
if (tempFile.isDirectory()) tempFile = File.createTempFile("pdf", null, tempFile);
FileOutputStream fout = new FileOutputStream(tempFile);
stp = new PdfStamper(reader, fout, pdfVersion, append);
stp.sigApp = new PdfSignatureAppearance(stp.stamper);
stp.sigApp.setTempFile(tempFile);
}
stp.sigApp.setOriginalout(os);
stp.sigApp.setStamper(stp);
stp.hasSignature = true;
PdfDictionary catalog = reader.getCatalog();
PdfDictionary acroForm =
(PdfDictionary) PdfReader.getPdfObject(catalog.get(PdfName.ACROFORM), catalog);
if (acroForm != null) {
acroForm.remove(PdfName.NEEDAPPEARANCES);
stp.stamper.markUsed(acroForm);
}
return stp;
}
