If you want to learn for the sake of expanding your knowledge range, Java is a pretty bad choice; there's very little that's novel about Java. The two advantages it has over Clojure right now are are 0) it's much easier to find employment in and 1) Clojure isn't yet suitable for Android development.

If you're getting into mobile phone development (likely Android), then you should start with Java. I think some people have managed to compile/run clojure to run on Android, but there are still some performance hurdles that will need to be overcome (true for dynamic languages running on Dalvik) before it becomes a viable language for mobile.