JAVA problem and generic type

Question

I ran into a problem with generic types:

public static class Field<T> { private Class<? extends T> clazz; public Field(Class<? extends T> clazz) { this.clazz = clazz; } } public static void main(String[] args) { // 1. (warning) Iterable is a raw type. References to generic type Iterable<T> should be parameterized. new Field<Iterable>(List.class); // 2. (error) The constructor Main.Field<Iterable<?>>(Class<List>) is undefined. new Field<Iterable<?>>(List.class); // 3. (error) *Simply unpossible* new Field<Iterable<?>>(List<?>.class); // 4. (warning) Type safety: Unchecked cast from Class<List> to Class<? extends Iterable<?>>. new Field<Iterable<?>>((Class<? extends Iterable<?>>) List.class); } 

What is the best solution between 1. and 4. (or any other, by the way)?

Answer 1

 public class Field <T> { private Class <? extends T> clazz; public <TT extends T> Field (Class <TT> clazz) { this.clazz = clazz; } public static void main (String [] args) { new Field <Iterable <?>> (List.class); } }