A powerful, cross platform, SQL database system
Java persistence using JDO, JPA or REST
Design, automate, operate and publish data pipelines at scale
TPC-C Like workload generator
A universal chemistry database system, using Java and any rdbms
TCJ (TPC-C via JDBC) is an implementation of TPC-C in Java using JDBC.
although fully functional, this is a pre-framework that you can extend