Try this:
class LoadMaps<E, T extends Collection<E> implements
AsyncCallback<T> {On Mon, Apr 11, 2011 at 11:43 AM, tanteanni <[email protected]> wrote: > meanwhile i tried your suggestions but i am struggling at getting the > right signature: > so i want a callback working of all kinds of collections and adding > the result to the given collection: > > at the moment i got this: > > private class LoadMaps<T extends Collection> implements > AsyncCallback<T> { > private T target; > > protected LoadMaps(T whereTo) { > target = whereTo; > } > > @Override > public void onFailure(Throwable caught) { > Window.alert(caught.getMessage()); > > } > > @Override > public void onSuccess(T result) { > target.addAll(result); > } > } > > the only problem is now: i can't call the constructor: > Map<String, List<String>> myMap = new HashMap<String, List<String>>(); > LoadMaps loadMaps = new LoadMaps(myMap); > > -->"The constructor AdminUnits.LoadMaps(TaskDoneEvent, > Map<String,List<String>>) is undefined" > > besides this i get "Type safety: The method addAll(Collection) belongs > to the raw type Collection. References to generic type Collection<E> > should be parameterized" in LoadMaps->onSuccess->target.addAll(result) > > so how to fix this > > On 11 Apr., 14:00, tanteanni <[email protected]> wrote: > > i am fairly new to gwt and struggling some how on "correct"/"nice" RPC > > implementation (it is working but code becomes ugly). On my first GWT > > based apps i often load some lists/data from db into front end. (Lists > > to be used in combo boxes for instance). > > > > so if i have a widget that needs 3 different lists (probably > > List<String> or Map<String, String>) i specify a service-method for > > each list. the problem is to load all those lists, i have to implement > > one class (...implements AsyncCallback) for each list. > > but the only difference between this implementations is that they load > > the result in different lists: > > public void onSuccess(){ > > list1 = result > > > > } > > > > so how to implement an abstract callback class that could load its > > "result" into a given list/object (- a field of mother class) > > > > (if "call by reference" would exist in java i would giv "list1" as an > > parameter for constructor and onSucces would load the result into this > > reference?!) > > > > an optimal implementation would be if the result type could be a > > generic type: A class lie this: > > > > class GeneralCallback<T> implements AsyncCallback<T>{ > > public GeneralCallback(T target){ > > ... > > > > } > > > > public onSuccess(T result){ > > target = result; > > > > } > > } > > > > is it possible to get such an abstract callback class? > > -- > You received this message because you are subscribed to the Google Groups > "Google Web Toolkit" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/google-web-toolkit?hl=en. > > -- Magno Machado Paulo http://blog.magnomachado.com.br http://code.google.com/p/emballo/ -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
