Question

I have a scenario wherein I need to specify a return type to the Synchrnous function, the code is as follows :

@RemoteServiceRelativePath("show_box")
public interface ShowBoxCommandService extends RemoteService{

 public ArrayList<String> showBox();

}

The implementation of the method on the server is :

public ArrayList<String> showBox() {

  ArrayList<String> box = new ArrayList<String>();
  Iterator<Box> boxes = BoxRegistry.getInstance().getBoxes();
  while (boxes.hasNext()) {
     box.add(boxes.next().toString());
  }
  return box;
}

I am trying to define the callback variable in the following format at the client side in order to call the method

 AsyncCallback<Void> callback = new AsyncCallback<Void>() {
           public void onFailure(Throwable caught) {
              // TODO: Do something with errors.
              // console was not started properly
           }

           @Override
           public void onSuccess(Void result) {
              // TODO Auto-generated method stub
              // dialog saying that the console is started succesfully

           }
        };

update with the aync interface code :

    public interface ShowBoxCommandServiceAsync {

   void showBox(AsyncCallback<ArrayList<String>> callback);

  }

But this is causing the definition of the method in the Async method to change.

Any ideas or clues will be helpful.

Thanks,
Bhavya

P.S. Apologies if this is a repetition

Answer 1

The callback should be:

AsyncCallback<ArrayList<String>> callback = new AsyncCallback<ArrayList<String>>() {
       public void onFailure(Throwable caught) {
          // TODO: Do something with errors.
          // console was not started properly
       }

       @Override
       public void onSuccess(ArrayList<String> result) {
          // TODO Auto-generated method stub
          // dialog saying that the console is started succesfully

       }
    };

If you don’t need to utilize the result then you can ignore it, but if that is the case, you should probably question your design and why you would need the method to return an ArrayList<String> in the first place.