this only works if you have a seperate method:
private List getOrders()
{
if (orders == null)
{
orders = DAO.getOrders()
}
}
iterator()
{
return getOrders().sublist(x,y).iterator()
}
size()
{
return getOrders().size();
}
detach()
{
orders = null;
}
johan
On 5/29/07, V. Jenks <[EMAIL PROTECTED]> wrote:
I'm trying to use a provider class for a DataView so I can do
paging/sorting,
etc. It looks like this:
************************************************
public class OrderProvider implements IDataProvider
{
private transient List<Order> orders;
public OrderProvider()
{
}
public Iterator iterator(int first, int count)
{
this.orders =
WicketHelper.<List<Order>>getDetachedModelObject(
OrderProxy.getAll(first, first + count));
return this.orders.iterator();
}
public IModel model(Object model)
{
return WicketHelper.getDetachedModel(model);
}
public int size()
{
return this.orders.size();
}
}
************************************************
I thought this would work but it looks like size() is called first, since
I
get a NPE:
************************************************
Caused by: java.lang.NullPointerException
at com.myapp.provider.OrderProvider.size(OrderProvider.java:36)
************************************************
It works if size() makes a call to the database to get a count of
records...but I'm trying to use a global field to prevent that data call.
Any suggestions?
--
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