Hi Fahad,
Thanks for your response. I’m sorry that we are still not on the same page and I hope this is more clear to you with this new information.
I have a common method to add annotation like this:
private static void addAnnotationToDocument(Document document) {
TextAnnotation text2 = new TextAnnotation(document.getPages().get_Item(1), new Rectangle(200, 500, 220, 550));
text2.setName (“Text anno name”);
text2.setTitle (“Text anno title”);
text2.setContents (“Text anno content”);
text2.setIcon (TextIcon.Comment);
text2.setColor (Color.getBlue());
document.getPages().get_Item(1).getAnnotations().add(text2);
PopupAnnotation popup2 = new PopupAnnotation(document.getPages().get_Item(1), new Rectangle(100, 400, 400, 500));
popup2.setName (“Popup anno name”);
popup2.setContents (“Popup anno content”);
popup2.setColor (Color.getGreen());
text2.setPopup (popup2);
document.getPages().get_Item(1).getAnnotations().add(popup2);
}
When I load a signed document directly from a file, call the above method, save to the same file, the signature is not broken which is good (see signed_doc_aspose_good.pdf)
Document document = new Document(dataDir + File.separatorChar + fileName);
addAnnotationToDocument(document);
document.save();
However, when I load a document to binary then create pdf document from there, then add annotation using the same shared api, then save to an output binary, then save to a file, the signature is broken which is bad (see signed_doc_aspose_bad.pdf).
File file = new File(dataDir, pdfFileName);
byte[] dataBinary = null;
try {
dataBinary = Files.readAllBytes(file.toPath());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Document document = new Document(new ByteArrayInputStream(dataBinary));
final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
addAnnotationToDocument(document);
document.save(outputStream);
byte[] outputBinary = outputStream.toByteArray();
Files.write(file.toPath(), outputBinary);
For your reference in my attachments:
+ signed_doc_org.pdf: original signed pdf
+ signed_doc_adobe_always_good.pdf: I used Adobe to add an annotation to the file, signature is not broken
+ signed_doc_aspose_good.pdf: my first case
+ signed_doc_aspose_bad.pdf: my second case
When you open my attachments, for good cases, it said that “Signed and and all signatures are valid, but with unsigned changes after the last signature.”. For bad cases, it said that "At least one signature is invalid."
I figured out Incremental Update is the key point here, all good cases have this feature, bad case does not. And WinMerge is my tool to check it (for Incremental Update: old content of signed pdf is not changed, new content is added only)
I would like to know if there is anyway to get through the “bad” case above except for saving to a temporary file. If not, can we consider to fix it in the next version?
Please let me know if this is still unclear to you. Thanks.
Best Regards,
Tuyen