Hello Sunil,

It is not pretty but you can:


Object o = list.get(0);

if (o instanceof Child) {
    ((Child)(o)).childMethod();
} else if (o instanceof Parent) {
     ((Parent)(o)).parentMethod();  
}


Or you can have a Enum in the parent that will store the type and in
that case you can just switch over it.

sunil kumar wrote:
> Hi Gustavo,
>
> Thank you for your reply.
> My problem is that, I have different subclasses of the Class Question. and 
> since the form is dynamic, there is no way for me to know which Question 
> objects are going to come through...
> I thought the only way is to have an interceptor or i just read about type 
> converters.. using which i can determine the correct class before the objects 
> reach my action class..
>
> --- On Wed, 22/4/09, Gustavo Felisberto <gustavo.felisbe...@wit-software.com> 
> wrote:
>
> From: Gustavo Felisberto <gustavo.felisbe...@wit-software.com>
> Subject: Re: How to get subclass objects in an arraylist?
> To: "Struts Users Mailing List" <user@struts.apache.org>
> Date: Wednesday, 22 April, 2009, 2:25 PM
>
> I guess the problem IS the fact that the type on elements in the list
> not being the correct type.
>
> public class Parent {
>     private String parent = "parent";
>
>     public String getParent() {
>         return parent;
>     }
>     public void setParent(String parent) {
>         this.parent = parent;
>     }
> }
>
> public class Child extends Parent{
>     private String childName = "child";
>     public String getChildName() {
>         return childName;
>     }
>     public void setChildName(String childName) {
>         this.childName = childName;
>     }
> }
>
> If you do:
>
>         List<Parent> list = new ArrayList<Parent>();
>         list.add(new Child());
>         list.get(0).getChildName();
>
> It will not build, you have to cast the Object to the correct type:
> ((Child)list.get(0)).getChildName();
>
>
> Same thing for jsp files.
>
>   


-- 
Gustavo Felisberto.
WIT-Software, Lda
Coimbra (Portugal), San Jose (California)
Phone: +351239801030
Web: http://www.wit-software.com 


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