I'm also developing my own which is both an RP (using JASPIC) and OP (using JAX-RS) framework. Each can stand on its own (I have tested the RP against Google), but it is designed to work together. https://github.com/trajano/openid-connect/
I wrote it to limit as much dependencies as possible, it actually does not have any runtime dependencies outside of itself and a Java EE 7 container. Unfortunately that limits things for WebSphere as WebSphere does not support Java EE 7 as of yet.
UPDATE: the good part is that there is OpenID Connect Support in IBM WebSphere for those who need to be on WebSphere.
