We got this new new requirement where we need to add the watermarking to the pdf documents. There are number of solution available but being a part of the my company (following the process)  we can not use any jar file available on the internet so when we checked the approved open source for my company I found that we can use iTEXT which support the pdf  documents and able to implement the new requirement for my project.

Took help from the following urls :

http://www.itextpdf.com/

http://www.java-connect.com/itext/add-watermark-in-PDF-document-using-java-iText-library.html

http://stackoverflow.com/questions/5278280/some-pdf-file-watermark-does-not-show-using-itext