具有未指定类型的泛型类的数组

MyGenericClass<?>[] array = new MyGenericClass<?>[10];

public class Singleton<T> {
    private static volatile Singleton<?> instance;
    private Singleton() {}
    public static <T> Singleton<T> getInstance() {
        if (instance == null) {
            synchronized (Singleton.class) {
                if (instance == null) {
                    instance = new Singleton<T>();
                }
            }
        }
        return (Singleton<T>) instance;
    }
}