I'm not sure Java is worth the effort at this point. If I'm going to have to keep updating every 6 months, I would rather use Go, which seems to have all that Java has to offer + the backing of a huge corporation.
import org.apache.hadoop.*;
import org.rapidoid.net.Server;
In case you are wondering people not only using languages for language features but also for the quality/quantity of libraries available in those languages. This is why is very hard to bootstrap a new language. Java has a ton of great libraries that are essential to big data and high performance backend services that you do not have in Go. I could mention tooling as well but we can skip it for now, the aforementioned library situation is enough to not to consider go already. Btw. the new OpenJDK releases are just fine for running Java and many companies use it extensively already (like AWS EMR for example) to run production code.