This is economically ineffective. You could write backend for most compilers, to target JVM (instead of pure machine codes), but result will be extremely slow.

This is economically ineffective. You could write backend for most compilers, to target JVM (instead of pure machine codes), but result will be extremely slow. Going in opposite way is much more fruitful - for example, compiling Java to native machine codes you will got about 10 times faster execution.