List<? extends MyType>

Question

I have a Java question about generics. I declared a generic list:

List listOfMyType;

Then in some method I try ins

Answer 1

You shouldn't need to use the wildcard capture syntax in your case, simply declaring

List listOfMytype;

should be enough. If you want to know exactly why, the Java Generics Tutorial has more than you would ever want to know about the esoteric craziness of Java Generics. Page 20 addresses your specific case.

As for why add with the wildcard capture does not work, it is because the compiler can't determine exactly what subclass of MyType the list will be in every case, so the compiler emits an error.