I have a Scala version Three.js in development. Some things already work (rendering, lights, shadows, materials, textures, cube-textures, raycasting), some not (mesh loaders). The version is currently closed-source, it should be used to power a yet unannounced commercial product. I plan to open source it once the product is released (or abandoned, whichever of it happens eventually).
The version is kept in sync with the main distribution, each revision takes a few hours to merge. It would be probably possible to provide a plain Java version by converting to Kotlin instead of Scala with
a moderate effort.
If there is someone with serious interest in such product, feel free to contact me.