OpenPDF is a free Java library for creating and editing PDF files, with a LGPL and MPL open source license. OpenPDF is based on a fork of iText. We welcome contributions from other developers. Please feel free to submit pull-requests and bugreports to this GitHub repository.
@akshayrrao-Sclera please give it a try using multithreading, and report back your results. My guess is that you need to add additional synchronization mechanisms.
I have to generate bulk pdf so does this library support multithreading?