I always got the impression Java the language was copyrighted, based on the hoops I had to jump through to get a copy to install.
You never, ever install Java the language on your computer, just like you can't install English the language on your computer.
What you install in the case of Java is the runtime environment (virtual machine and bytecode for the class libraries) and maybe the SDK (compiler, debugger, maybe IDE). Languages only exist in people's minds.
That is a very important distinction. Software is copyrightable, but languages aren't.
Now Oracle tries to lump APIs (which are abstract things and also exist purely in the mind) into the same category as software, and claims that Google infringes their copyright by reimplementing some of the Java core APIs.
(Oracle also has some other claims, like that Google copied 9 (!) lines of code, claims that Google copied documentation, and two patent violations. But those claims are all pretty minor, and won't affect the software world as a large nearly as much as the API copyright claims).