Just wanted to announce that I am nearing completion of the TestRail Java API SDK v1.1. It has not been merged into master as I have not extensively tested it. Currently it lives on the branch ST-67.
This new version has helper methods for every single api endpoint I could find in the TestRail API v2 Documentation.
If you can test it and/or have any feedback on how to improve this SDK, I encourage you to try it out and tell me anything I can do to make using it easier.