Hah. They don't have one now. The de facto solution is Maven. Java itself doesn't actually have a module system like the one discussed for Go. It is merely a access control system rather than a dependency system.
To be clear, I give the Java people shit about it all the time and was on the original Java module system JSR that was supposed to deliver it. In the end, the Sun people yanked the dependency part and shipped a module system that is really only useful to the JDK.
