Flatten using PDFBOX3

[Frédéric Ravetier]

Hello,

I am trying to Flatten a PDF using PDFBox3 by doing :

private static void flattenPDF(String src, String dst) throws IOException {
    PDDocument doc = Loader.loadPDF(new RandomAccessReadBufferedFile( src ));

    PDDocumentCatalog catalog = doc.getDocumentCatalog();
    PDAcroForm acroForm = catalog.getAcroForm();
    if (acroForm == null){
        logger.debug("This document does not contains any form,
nothing to do...");
    }else {
        acroForm.setNeedAppearances(false);
        acroForm.flatten();// Flatten using pdfbox3
    }
    doc.save(dst);
    doc.close();
}

It works but it creates in some cases a document that is not readable using
PDFBox 2 where I get this error:
java.io.IOException: COSObject{525, 0} cannot be assigned to offset
1528842, this belongs to COSObject{4196, 0}

at
org.apache.pdfbox.pdfparser.COSParser.parseDictObjects(COSParser.java:736)
at org.apache.pdfbox.pdfparser.PDFParser.initialParse(PDFParser.java:185)
at org.apache.pdfbox.pdfparser.PDFParser.parse(PDFParser.java:231)
at org.apache.pdfbox.pdmodel.PDDocument.load(PDDocument.java:1233)
at org.apache.pdfbox.pdmodel.PDDocument.load(PDDocument.java:1133)

With the following code :

System.out.printf("\n*\n* demo.pdf\n*\n");
try (
    InputStream resource =
getClass().getResourceAsStream("/mkl/testarea/pdfbox2/extract/bad-annot-1.pdf")
   ) {
    //OutputStream result = new FileOutputStream(new
File(RESULT_FOLDER, "bad-pdf-sign.pdf"));
    PDDocument pdDocument = PDDocument.load(resource);
    System.out.printf("Producer of document : %s\n",
pdDocument.getDocumentInformation().getProducer());
    AccessPermission accessPermission = pdDocument.getCurrentAccessPermission();
    if (accessPermission.isReadOnly()) {
        System.out.printf("The document cannot be modified (read-only)");
    }

    if (!accessPermission.canModify()) {
        System.out.printf("Cannot modify the document");
    }

    if (!accessPermission.canModifyAnnotations()) {
        System.out.printf("Cannot modify the annotation");
    }

    if (!accessPermission.canFillInForm()) {
        System.out.printf("Cannot fill in form");
    }

}


Do you have any ideas why ?

I can not share the document (confidential) :(

Best regards,
Fred