Typing a few less characters on boiler plate doesn't buy you anything, unless you're a slow/lazy programmer.
Typing "public static class" is boring, yes. But it's irrelevant. It can't contain bugs, so getting rid of that doesn't buy you anything at all.
Less typing != less bugs (When the code is compiled, statically typed, etc).
There is absolutely no reason to duplicate code in Java, and if you're copy/paste coding, it's not the languages fault, it's yours.