This is called a "generic method", and you're just giving the type
signature of the method. Here's an example from our code.
public static > NumberField
withMinimum(String id, T min) {
NumberField f = new NumberField(id);
f.add(new MinimumValidator(min));
> public IWrapModel wrapOnInheritance(Component component,Class
> type)
The Class parameter is only needed if you intend to do "new W();" or the
like in the method (the Class is then something the compiler can grab hold of
for calling the constructor). For just passing the type parameter to oth
I actually meant the no-argument version of "of()". Since this is getting
off-topic, I suggest you search around under "java type erasure." There are
people far more expert than I to describe what's going on. :)
On Thu, Jul 28, 2011 at 9:26 PM, Ben Tilford wrote:
> Right but Model.of accepts an
Right but Model.of accepts an instance of the generic type so it's not lost
and is available at runtime.
static Model of(T instance)
vs.
public IWrapModel wrapOnInheritance(Component component)
On Thu, Jul 28, 2011 at 6:33 PM, Dan Retzlaff wrote:
> Generic types are lost by the time the method
Generic types are lost by the time the method is executed, so there's really
nothing the method implementation could check. Another fun example
is org.apache.wicket.model.Model#of(). The general subject is called type
erasure, and is one of the more confusing aspects of Java generics.
On Thu, Jul
Without a Class argument how is it returning/casting correctly? Shouldn't it
be
public IWrapModel wrapOnInheritance(Component component,Class
type)
to make W available within the method?
On Thu, Jul 28, 2011 at 12:40 PM, Dan Retzlaff wrote:
> The first let's the compiler know that the secon
The first let's the compiler know that the second is a generic type
and not a reference to some class named W. It's just syntax.
On Thu, Jul 28, 2011 at 10:48 AM, Niranjan Rao wrote:
> Ok, I admit it - I don't understand this function at all defined in
> IComponentInheritedModel
>
> public IW
This syntax is for use when you need a generic placeholder.
In this case, it means that is determined by the call site:
IModel model = OtherModel.wrapOnInheritance( Component );
The above means that W is checked to be "BusinessObject" for all
occurrences of W.
A better to understand example
Ok, I admit it - I don't understand this function at all defined in
IComponentInheritedModel
public IWrapModel wrapOnInheritance(Component component)
I don't understand meaning of and IWrapModel. I know generics
generally, but this syntax has been baffling me. Based on what eclipse
is tryin
