This week's book giveaways are in the Jython/Python and Object-Oriented programming forums. We're giving away four copies each of Machine Learning for Business: Using Amazon SageMaker and Jupyter and Object Design Style Guide and have the authors on-line! See this thread and this one for details.
Look on the sourceForge there is a set of API's to generate PDF's... I am sure they can provide a least basic PDF viewing. There was also a post on a javaranch forum about the different PDF viewer. The post was made by Benjamin LEONARD (an dammed good java developper & more over a frien of mine). I remember he gave 2 package to do so !