A 'bare bones' on the subject would probably be a good starting point, though I would expect (without knowing good deal more about it than I do) that it would require more work than most of the other BB pages.
I would keep in mind that you'll have to either select a specific Java implementation (again, not knowing enough about it, I imagine gjc is probably easiest to work with for this purpose, but you would know better than I would), or else have separate sections (or even separate pages) for different compilers and JVMs. You will also need to go into detail about a number of issues that don't arise with most other languages, such as porting the JVM and the JIT compiler, implementing the garbage collector(s), handling the JNI to call native code, and so on. Being in a similar position myself (except with a language that doesn't even exist yet), I can tell you that there are more than a few issues that you will need to explain that simply don't come up with, for example, Ada. You can anticipate it taking a fairly long time to get it beyond being just a stub.
Nice introduction. In case of the implementation in fact it's simpler (Java is standardized much more than C), but I'll try to write about it in the wiki.
Though I would not be interested in using Java, I would enjoy reading how it is done
Ok, I'll try to show it from the perspective of C developers.
If you can formulate something truly Bare Bones, that'd certainly be a nice thing. However if it goes more into the direction of "clone this git repository" or "use this support code", then it's probably ill-advised to present the beast in sheep's clothing to the unprepared newcomer.
Do you think I'll start to advertise my OS? It's not the case. But it is much easier to get examples from my work.