You can at best implement a mimicry of Erlang's message passing in Java.

With sufficient effort, you can have the equivalent of no shared mutable data.

What you cannot have is completely separate heaps, so that if one thread crashes for whatever reason it doesn't take your application down.

Also, good luck trying to find a garbage collector that supports completely separate heaps that isn't a direct copy/near-identical implementation of the BEAM[1] VM's GC.

[1] The virtual machine that is the stock VM for Erlang. (In fact I don't know of any others but I have never looked.)