No casting is required. Try this: BaseClass baseObject = null; DropDownChoice<BaseClass> dropDown = new DropDownChoice<BaseClass>("id"); dropDown.getChoiceRenderer().getDisplayValue(null);
This will compile (it won't run because you'll get an NPE if the display value method doesn't accept null). As I said, you don't have to declare your local variable "dropDown" with type variable wildcards. On Sat, Jun 13, 2009 at 6:23 AM, Martin Makundi<martin.maku...@koodaripalvelut.com> wrote: > No. The compiler does not allow. If DropDownChoice is of type <? > extends BaseClass> then the problem is that it assumes that > getChoiceRenderer() is also of type <? extends BaseClass>. Now at > runtime, because of the wildcard, I do not know what class I have, and > I absolutely cannot use the renderer. The only workaround is to cast > the renderer into <BaseClass> (which it actually is!!) and that works, > but the warning remains. > > Tricky.... > > ** > Martin > > 2009/6/13 James Carman <jcar...@carmanconsulting.com>: >> But, the compiler only knows what you're allowed to do by the type of >> the variable. You do not need to declare your variables with the >> wildcards. >> >> On Fri, Jun 12, 2009 at 6:31 PM, Cristi Manole<cristiman...@gmail.com> wrote: >>> declaration is not the problem. from what i remember from generics (I might >>> be wrong), you're not allowed to instantiate "generically". you have to tell >>> the compiler exactly what type you want. at runtime it has no idea about >>> generics. >>> >>> On Sat, Jun 13, 2009 at 12:41 AM, James Carman >>> <ja...@carmanconsulting.com>wrote: >>> >>>> Just because the constructor is declared that way (with the ?) doesn't mean >>>> you have to declare your variables that way. >>>> >>>> On Jun 12, 2009 4:43 PM, "Martin Makundi" < >>>> martin.maku...@koodaripalvelut.com> wrote: >>>> >>>> > new DropDownChoice<BaseClass> ? >>>> >>>> Maybe ... >>>> >>>> ** >>>> Martin >>>> >>>> > > On Fri, Jun 12, 2009 at 6:06 AM, Martin > Makundi< >>>> martin.maku...@koodaripalvelut.com> wrote: >>... >>>> >>> >>> >>> >>> -- >>> Cristi Manole >>> >>> Nova Creator Software >>> www.novacreator.com >>> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >> For additional commands, e-mail: users-h...@wicket.apache.org >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org For additional commands, e-mail: users-h...@wicket.apache.org