🚀 go-pugleaf

Bobby Healy wrote:
> 
> I want to be able to save to disk the entire state of a
> piece of my dialog. It's basically a listbox defined
> as follows-:
> 
> public class rwd_writablevectormodel extends
>   ListControl implements WritableVectorModel,Serializable

Do you really need to implement WritableVectorModel since
ListControl essentially implements the methods of this interface?
I suspect that the "VectorModel" in the "implements" phrase
of ListControl is a typo.  See the comment just above the
method, ListControl.canSet().
 
>[...]
>          out.writeObject(cListbox);

           out.flush();  ????

>          out.close();
> 
> and reloading it as follows-:

>             rwd_writablevectormodel rc=(rwd_writablevectormodel)in.readObject();

Do you test for ( rwd_writablevectormodel != null ) after this
before doing anything with it?

> When I try to work with the loaded object (to add a listner),
> I get the following exception-:
> 
> [...]
> System Error:   java.lang.NullPointerException
> 
> The code to add the handler is as follows-:
> 
>       jPanelList.addSelectionListener(...);

Are "cListBox" and "jPanelList" of type "rwd_writablevectormodel"?

Such serialization should work.  If not, then you have mixed
types, or you've put code in the wrong place and you are trying
to invoke methods on a non-existant object.  Can't really
tell from the incomplete and a bit incoherent snippets presented.


Paul Furbacher