How to get GenericTypes from a Field (java)

public static List<Class<?>> getGenericTypes(Field f){
        List<Type> list = Arrays.asList(((ParameterizedType) f.getGenericType()).getActualTypeArguments());
        return list.stream()
            .map((a)->(Class<?>)a)
            .collect(Collectors.toList());
    }

/* example */
public class A(){
     List<String> list = new ArrayList<>();

     public static void main(String[] args){
         Field f = A.class.getDeclaredField("list");
         System.out.println(getGenericTypes(f)); // output --> class java.lang.String
     }
}