PDF metadata removal using Java

Question

How to remove metadata on PDF using Java?

Is IText will do or any other frameworks have ability to do this? I didn't find any examples or Classes which will remove metadata using IText. If anybody done this before or any ideas?

Please share your views.

Thanks in advance.

Answer 1

First you need to differentiate since there are two types of metadata in the PDF:

1. XMP meta data
2. DID (document information dictionary, the old way)

The first you remove like the following:

PdfReader reader = stamper.getReader();
reader.getCatalog().remove(PdfName.METADATA);
reader.removeUnusedObjects();

The 2nd you remove like SANN3 has mentioned:

HashMap<String, String> info = super.reader.getInfo();
info.put("Title", null);
info.put("Author", null);
info.put("Subject", null);
info.put("Keywords", null);
info.put("Creator", null);
info.put("Producer", null;
info.put("CreationDate", null);
info.put("ModDate", null);
info.put("Trapped", null);
stamper.setMoreInfo(info);

If you then search the PDF with a text editor you won't find the /INFO dictionary nor XMP meta data...

Answer 2

Try this code

PdfReader readInputPDF = new PdfReader("sample.pdf");
HashMap<String, String> hMap = readInputPDF.getInfo();
PdfStamper stamper = new PdfStamper(readInputPDF, new FileOutputStream("sample1.pdf"));
hMap.put("Author", null);
stamper.setMoreInfo(hMap);
stamper.close();

Add the Metadata properties to the map which you want to remove from the PDF.

Answer 3

Updated for those using PdfBox 2.x

File pdf = new File("student-scorecard.pdf";
PDDocument document = PDDocument.load(pdf);
PDDocumentInformation information = document.getDocumentInformation();
if(information != null) {
  document.setDocumentInformation(new PDDocumentInformation());
  document.save("student-scorecard-anonymized.pdf");
}
document.getDocumentCatalog().setMetadata(null); // Tilman Hausherr 
document.close();

Answer 4

Thanks @Magnus Updated for those using PdfBox 2.x

In my case I had to change the order to get it work:

 File pdf = new File("student-scorecard.pdf";
 PDDocument document = PDDocument.load(pdf);
 PDDocumentInformation information = document.getDocumentInformation();
 if(information != null) {
     document.setDocumentInformation(new PDDocumentInformation());
     document.getDocumentCatalog().setMetadata(null); // Tilman Hausherr 
     document.save("student-scorecard-anonymized.pdf");
 }
 document.close();