Question

Im doing a program in GWT. Here is the snippet where Im having problem

 private String[] populateRSSData() {
  1==>> String[] data = null;
  try {
   new RequestBuilder(RequestBuilder.GET,
     "../database.php?action=populaterss").sendRequest(null,
     new RequestCallback() {

      @Override
      public void onResponseReceived(Request request,
        Response response) {
       2==>> data=response.getText().split("~");
      }

      @Override
      public void onError(Request request, Throwable exception) {
       Window.alert(exception.getMessage());
      }
     });
  } catch (RequestException e) {
   Window.alert(e.getMessage());
  }

  return data;
 }

Now the problem arises that I get an error that the variable 1==>> data should be declared final. But if I declare it as final then i cannot store the datas in 2==>>

The error i get

Cannot refer to a non-final variable data inside an inner class defined in a different method RSS_Manager.java

Please suggest

Answer 1

Even if you manage to get over the error, the function will not do what you intend it to do.
The callback you are creating will be notified asynchronously of the response received from server while your method populateRSSData() will return immediately.

You need to rethink your design taking the asynchrony into account.

EDIT: see Getting Used to Asynchronous Calls

EDIT:
Quote from the above link

The important issue to understand is that that the code that follows the RPC call invocation will be executed while the actual round trip to the server is still in progress. Although the code inside the onSuccess() method is defined inline with the call, it will not be executed until both the calling code returns back to the JavaScript main loop, and the result message from the server returns.