Inheriting from a Generic type

Question

Hello all,
I'm doing some tests on compiling generics and get confused about the case where a class not considered as a generic could inherit from a generic type. Shouldn't it be implicitly considered as a generic ?
To illustrate my problem, consider the following:
I declare a class MyCollection as following:
public class MyCollection extends Vector {...}
vector is a Generic type as it is declared as public Vector<E> {...}
But if I try to instantiate MyCollection, I'm not allowed to do it as:
MyCollection<Object> col = new MyCollection<Object>();
but I'm allowed to do:
MyCollection col = new MyCollection();
So what happens to the E generic variable of Vector ?
I can't clearly explain what is MyCollection. I should have implicitly considered it as a Generic type.
Can someone explain ?

Answer 1

Not really. I've probably not been clear.
Java5 exposes in its apis a class defined as:
public class Vector<E> ...
Now I define my own colletion class defined as:
public class MyCollection extends Vector { ...
This syntax is allowed by the compiler. Note that I
didn't define my class MyCollection as a Generic.
BUT, as the superclass IS a generic, How is
interpreted MyCollection ?
As a kind of Vector<Object> ?
What about the E generic type defined in Vector, the
superclass ?
I Thought, this way of feining my class MyCollection
implied it to be Generic also, i.e. that this kind of
definition means implcitly that it is equivalent as
defining:
public class MyCollection<E> extends Vector<E> ...
But that's not clear to me !!!
What about you all ???Your definition:
public class MyCollection extends Vector
does not make MyCollection generic implicitly, or at all. It is equivalent to
public class MyCollection extends Vector<Object>
which is basically the same as using a pre-1.5 Vector. The superclass may be defined as a generic type but that doesn't matter here. MyCollection is not generic, period. It can be interpreted "as a kind of Vector<Object>".
The superclass doesn't matter to whether or not your class is generic. Your class is generic if and only if you declare it as a generic
The only way to make your class a proper generic extension of Vector is:
public class MyCollection<E> extends Vector<E>.
Is there any reason you don't want to do this?