The world "primarily" is important here. Sure, you _can_ use Java for embedded and even real-time stuff. Some games are written in Java, etc. But no one would say that Java is the primary language of choice in such domains.
Java has been used for soft real-time systems, such as payment processors or real-time bidding. For a GC-ed language, its latency guarantees can be pretty OK due to having good garbage collectors and runtime optimizations.
But, yes, obviously it can't be used for systems where latency is a matter of life and death, like operating the breaks on a car.
There actually are special, hard real-time JVMs that are used in missile defense systems. Do note that hard real time is not about performance (and as computers are so fast, you really don’t need much time for millions of calculations), but the guarantee of executing it in X time. But it does require very special engineering.
