Re: Generics ?

From:
Knute Johnson <nospam@knutejohnson.com>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 16 Dec 2011 22:01:08 -0800
Message-ID:
<jchb74$n8m$1@dont-email.me>
On 12/16/2011 2:10 AM, Roedy Green wrote:

On Thu, 15 Dec 2011 21:48:06 -0800, Knute Johnson
<nospam@knutejohnson.com> wrote, quoted or indirectly quoted someone
who said :

public class KList extends JList {
     ListModel model = new DefaultListModel();


If you were just using JList by itself you would say:

  final JList<String> flavour = new JList<String>( new String[] {
                     "strawberry", "chocolate", "vanilla" } );

Your new class KList can have a built-in fixed contained type, e.g.
String or it can have a variable one.

The first is pretty obvious :

class KList extends JList<String>

The second you can discover by looking for some similar Sun code in
src.zip, e.g.

public interface MutableComboBoxModel<E> extends ComboBoxModel<E> {

so I would think

KList<E> extends JList<E>
should work.

For additional hints, see http://mindprod.com/jgloss/generics.html
and links

I have not tested this and quite commonly things in generics I think
should work do not. Take this just as a hint of something to try.


Yeah, unfortunately that doesn't work. Is it possible to extend JList
and not get unchecked warnings?

--

Knute Johnson

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