As you might have realized from the posts on this forum, the new JPA Certification exam is tough. The questions on the exam require you to have a thorough understanding of all the topics. You will be required to know the hows and whys of JPA queries, Criteria Builder queries, and EntityManager API in detail. It will be very difficult to pass this exam without hands on coding.
To help candidates with their preparation, we have come up with a sample application that illustrates all the aspects of JPA and allows you to play with the actual code and see the impact of your changes right away. It populates the database with appropriate data against which you can try out Criteria Builder queries and arbitrary business logic code.
We are using this app to test out questions for our JPA exam simulator. We hope that it will be helpful for others as well and so we have made it available for download for free.