Just a silly question.
Where did ListUtils come from?? I can't find this
in my JDK1.4.2.
Thanks
----- Original Message -----
From: "Hubert Rabago" <[EMAIL PROTECTED]>
To: "Struts Users Mailing List" <[EMAIL PROTECTED]>
Sent: Friday, September 03, 2004 7:40 AM
Subject: Re: Not happy with approaches.. looking for better/other
suggestions
> Have you tried using ListUtils.lazyList() for this? I just tried it
> on a sample app and it works in cases like this.
>
> - Hubert
>
> On Thu, 02 Sep 2004 14:27:32 -0400, Rick Reumann <[EMAIL PROTECTED]>
wrote:
> > One of the most frustrating things I run into when developing Struts
> > applications is the problem of when you want to use a request scoped
> > ActionForm but you need to populate a collection that is one of your
> > ActionForm properties. The problem is the classic index out of bounds
> > exception if you do not have your collection populated with enough
objects.
> >
> > For example imagine the case where you might want to edit a bunch of
> > Access definitions on one form.
> >
> > So in an ActionForm property you have:
> >
> > Collection accessDefinitions;
> >
> > In your Action before you get to the form you populate your form:
> >
> > ((AccessForm)form).setAccessDefinitions( aCollectionOfDefs );
> >
> > Your JSP then displays the access definition properties for the user to
> > edit:
> >
> > (condensed and table formatting removed:)
> >
> > <c:forEach items="${accessForm.accessDefinitions}" var="access"
> > varStatus="status">
> > <html:text property="accessDefinitions[${status.index}].name"/>
> > <html:text property="accessDefinitions[${status.index}].description"/>
> > </c:forEach>
> >
> > Now the problem will be when you submit this form. If this form was
> > given request scope in the action mapping, you'll end up with errors
> > since BeanUtils can not populate the Collection. You need to have the
> > correct size in place for 'accessDefinitions' to allow for population.
> >
> > There are several solutions that have been proposed by searching the
> > list archives.
> >
> > The easiest alternative is of course to just put your form in Session
> > scope, but that is such a waste in my opinion.
> >
> > Another approach would be something like:
> >
> > In reset() of ActionForm:
> >
> > public void reset(ActionMapping actionMapping, HttpServletRequest
request) {
> > if ( request.getParameter("accessDefinitionsSize") != null ) {
> > int accessDefinitionsSize = new
> > Integer(request.getParameter("accessDefinitionsSize")).intValue();
> > accessDefinitions = new ArrayList(accessDefinitionsSize);
> > for (int i=0;i<accessDefinitionsSize;i++) {
> > accessDefinitions.add(new AccessDefinitionVO());
> > }
> > }
> > }
> >
> > Then in your JSP (code snipped just showing releveant portion):
> >
> > <c:forEach items="${accessForm.accessDefinitions}" var="access"
> > varStatus="status">
> > ....
> > <c:set var="accessDefinitionsSize" value="${status.count}"/>
> > </c:forEach>
> > <input type="hidden" name="accessDefinitionsSize"
> > value="${accessDefinitionsSize}"/>
> >
> > The above works 'ok' but it's so much extra code. I've thought of just
> > adding the accessDefinitionsSize attribute to the Session in the Action
> > that is called right be the form is set up. Then the reset method can
> > pull it right from there. An int in the session won't be too much
> > overhead. But I'm not sure if I like that approach that much either
> > (although I'm leaning towards just doing it that way).
> >
> > Of course I don't like the approaches that call a business class from
> > the reset to get the size.
> >
> > Any suggestions welcome.
> >
> > --
> > Rick
> >
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> >
> >
>
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