Oh, I think I misunderstood then. Because I thought pdfbox has its own signature implementation and I was trying to use it without implementing my signature method for the moment. If we must always provide signature implementation ourselves with the sign method in signatureInterface, what does external signing mean in this context? Sorry, I have looked into the docs and the site and couldn't make sense of it.
Thanks for your quick response by the way, Tilman. On Thu, Jul 2, 2020 at 9:06 AM Tilman Hausherr <[email protected]> wrote: > Hi, > > This means writeExternalSignature() was called with a null argument. > That method is called if signatureInterface is set, but > signatureInterface.sign() has returned is null. > > So you need to find out why your sign() method has returned null. > > Tilman > > Am 02.07.2020 um 08:07 schrieb Okan Konur: > > Hello, hope you are well. > > > > We are trying to get PADES working with PDFBox. > > I am working on > > CreateSignature.java > > > > I checked out the trunk version of examples signature directory. > > Then changed the Loader class reference with the 2.0 branch version, > after > > I realized the loader class is new. I am working with latest > > pdfbox-2.0.20.jar. > > > > My problem is at the document.saveIncremental(output) line. > > I get the following exception: > > > > Exception in thread "main" java.lang.NullPointerException > > at org.apache.pdfbox.util.Hex.getBytes(Hex.java:83) > > at > > > org.apache.pdfbox.pdfwriter.COSWriter.writeExternalSignature(COSWriter.java:792) > > at > > > org.apache.pdfbox.pdfwriter.COSWriter.doWriteSignature(COSWriter.java:745) > > at > > > org.apache.pdfbox.pdfwriter.COSWriter.visitFromDocument(COSWriter.java:1150) > > at org.apache.pdfbox.cos.COSDocument.accept(COSDocument.java:452) > > at org.apache.pdfbox.pdfwriter.COSWriter.write(COSWriter.java:1386) > > at > > > org.apache.pdfbox.pdmodel.PDDocument.saveIncremental(PDDocument.java:1392) > > at CreateSignature.signDetached(CreateSignature.java:157) > > at CreateSignature.signDetached(CreateSignature.java:96) > > at CreateSignature.main(CreateSignature.java:180) > > > > > > I can post the source code but it is mostly the same with the repo > version. > > I just changed the keystore and pdf file path. > > > > Can you kindly point me in the right direction? > > > > Thanks > > > > Okan > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
