Annotated-Parameter Signature
Annotated-Parameter Signature In this signature, return types are safely checked. Differently than the default signature, an advice can't return an invalid typed value. For example, by declaring to return java.lang.Object when the joinpoint return type is java.util.Collection, an advice could return a java.lang.String value (this would result in a RuntimeException). When using annotated-parameter signature, this code wouldn't compile. In that case, an advice could, however, return a java.util.List typed value, since this class is a subtype of the joinpoint return type.