how to uninstall java?

I downloaded Java, only to realize I don't need it so I wanted to uninstall it.

Only, I tried to uninstall by sudo rm -rf /System/Library/Java in the Terminal and now it says no such file or directory. It seems as though java is still there, but it won't open when I go to Java Preferences in Utilities.

So how do I correctly uninstall Java at this point?

Also, if I upgrade to Mountain Lion (I currently have Lion) would the Java be automatically uninstalled again?