Few months ago I had some free time and played with the idea of creating a Java based miner. I wrote the mining part in OpenCL ("from scratch" implementation, no code is used from any existing miner).
After a lot of tunning I managed to get it on par with XMR-stak - I was getting almost the same hashrate out of my Vega 64 from both mine and xmr-stak, i.e. ~2040 h/s.
However, so far mine miner lacks the networking functionality that is needed to communicate with a mining pool. Also there is need some additional work to be done, all-in-all it will require 30 to 45 days to finish it.
I was wondering, is there in the community interest for a Java based miner? Any examples for specific use cases (like on Android for example)?