The JSR 308 proposal mentioned that there might be trust issues for annotations that can be subclassed outside a trusted framework. I contend that this is not a severe problem since it occurs with normal classes already.
To still address this issue, I decided to allow the final modifier for annotations: An annotation that is final cannot be subclassed, just like a final class cannot be extended.
1 2 3 4 5 6 7 8 | final @interface FinalAnnotation { String value(); } // ERROR: cannot inherit from final FinalAnnotation @interface SubAnnotation extends FinalAnnotation { int i(); } |
Again, the change involved only half a dozen lines.
