How to convert pdfstamper to byte array

Question

In my application, i need to read the existing pdf and add barcode to the existing PDF and pass it to output stream. here the existing pdf is like template. I am using iText jar

Answer 1

Your question is unclear. I assume that you want to write to a ByteArrayOutputStream instead of to a FileOutputStream. There are different examples on how to do that on the iText web site.

See for instance the FormServlet example where it says:

// We create an OutputStream for the new PDF
ByteArrayOutputStream baos = new ByteArrayOutputStream();
// Now we create the PDF
PdfStamper stamper = new PdfStamper(reader, baos);

Then later in the example, we do this:

// We write the PDF bytes to the OutputStream
OutputStream os = response.getOutputStream();
baos.writeTo(os);

If you want a byte[], you can simply do this:

byte[] pdfBytes = baos.toByteArray();

I hope your question wasn't about writing a PdfContentByte stream to a byte[] because that wouldn't make sense: a content stream doesn't contain any resources such as fonts, images, form XObjects, etc...