Using iText 2.1.7 to merge large PDFs

I am using an older version of iText (2.1.7) to merge PDFs. Because that is the last version under the MPL available to me. I cannot change this.

Anyways. I am trying to merge multiple PDFs. Everything seems to work ok, but when I go over about 1500 pages, then the generated PDF fails to open (behaves as if it is corrupted)

This is how I am doing it:

private byte mergePDFs(List<byte> pdfBytesList) throws DocumentException, IOException {
Document document = new Document();
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
PdfCopy copy = new PdfCopy(document, outputStream);
document.open();

for (byte pdfByteArray : pdfBytesList) {
ByteArrayInputStream readerStream = new ByteArrayInputStream(pdfByteArray);
PdfReader reader = new PdfReader(readerStream);

for (int i = 0; i < reader.getNumberOfPages(); ) {
copy.addPage(copy.getImportedPage(reader, ++i));
}

copy.freeReader(reader);
reader.close();
}

document.close();

return outputStream.toByteArray();
}


Is this the correct approach? Is there anything about this that would hint at breaking when going over a certain amount of pages? There are no exceptions thrown or anything.

Right approach, wrong version. In 2009, there was a limit on the size of the PDF in iText. Please upgrade. This question should be closed as off-topic: it's a problem that can no longer be reproduced. (People shouldn't use versions of iText that are 9 years old.)
– Bruno Lowagie
2 days ago

@BrunoLowagie fair point. I wish I could use a later version. thanks for the input.
– Seephor
yesterday

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