What do you think about this idea? I hope the fact that I did not get any responses yet does not mean that you are not interested or that I annoyed you.
> JDK-6184881 describes that Object.getClass() should ideally not return > classes of raw types anymore but instead use wildcards. The problem is that, > as noted in the comments, this breaks compability with previously written > code and therefore this change is not very likely (at the moment?). > > However, the report does not cover the class literal expression > (https://docs.oracle.com/javase/specs/jls/se11/html/jls-15.html#jls-15.8.2). > > It would be good to allow the usage of the wildcard (`?`) for this > expression: > List<?>.class => Class<List<?>> > > Since it is currently not allowed to provide type parameters in the class > literal expression there should not be any compatibility issues. > Additionally if at some point JDK-6184881 is fixed for class literals as > well, then the expression List<?>.class could just be a verbose variant of > List.class without causing any problems either. > > > This would make writing methods or constructors which determine a generic > type based on a given class easier for generic classes, e.g.: > > public class MyContainer<T> { > private final Class<T> valueClass; > > public MyContainer(Class<T> valueClass) { > this.valueClass = valueClass; > } > > public static void main(String[] args) { > MyContainer<String> stringContainer = new > MyContainer<>(String.class); > // Have to use raw type (or verbose casting of class) > MyContainer<List> listContainer = new MyContainer<>(List.class); > > // With suggested change: > MyContainer<List<?>> listContainer = new > MyContainer<>(List<?>.class); > } > } >
