html:iterate problem when session time out

[j2eetechnicalguy]

Hi,

Any one please help me to solve the following problem?

I am using an array in a form and html:iterate on a jsp. When session time out, I got the following error:

10:09:58,116 ERROR [Engine] StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
java.lang.IllegalArgumentException: Null property value for 'orderDetails[1]'

It looks after session time out, the form is not populated correctly. The index passed from jsp is 1, but the array in the session is gone. Here is the form code:

public class OrderDetailForm extends ActionForm
{
private OrderDetailsVO[] orderDetails = new OrderDetailsVO[0];
public OrderDetailsVO getOrderDetails(int index){
if(index>=orderDetails.length){
return null; // hopefully session error, call validate......
}
return orderDetails[index];
}
}

Any ideas please?

Thank you very much,
Simon Chen