One AsyncTask for multiple Activities

I'm writting an app that uses WebServices to retrieve data. Initially I had a private `AsyncTask` class for each activity that needed data from the WebService. But I've decided to make the code simpler by creating `AsyncTask` as a public class. All works fine, but my problem is when I want to access the retrieved data from the `AsyncTask`. For example this is my `AsyncTask` class. ``` public class RestServiceTask extends AsyncTask<RestRequest, Integer, Integer> { /** progress dialog to show user that the backup is processing. */ private ProgressDialog dialog; private RestResponse response; private Context context; public RestServiceTask(Context context) { this.context = context; //...Show Dialog } protected Integer doInBackground(RestRequest... requests) { int status = RestServiceCaller.RET_SUCCESS; try { response = new RestServiceCaller().execute(requests[0]); } catch(Exception e) { //TODO comprobar tipo error status = RestServiceCaller.RET_ERR_WEBSERVICE; e.printStackTrace(); } return status; } protected void onPreExecute() { response = null; } protected void onPostExecute(Integer result) { if (dialog.isShowing()) { dialog.dismiss(); } switch (result) { case RestServiceCaller.RET_ERR_NETWORK: Toast.makeText( context, context.getResources().getString( R.string.msg_error_network_unavailable), Toast.LENGTH_LONG).show(); break; case RestServiceCaller.RET_ERR_WEBSERVICE: Toast.makeText( context, context.getResources().getString( R.string.msg_error_webservice), Toast.LENGTH_LONG) .show(); break; default: break; } } public RestResponse getResponse() throws InterruptedException { return response; } } ``` `RestServiceCaller`, `RestRequest` and `RestResponse` are clasess that I've created. I'm using the task like this: ``` RestRequest request = new JSONRestRequest(); request.setMethod(RestRequest.GET_METHOD); request.setURL(Global.WS_USER); HashMap<String, Object> content = new HashMap<String, Object>() { { put(Global.KEY_USERNAME, username.getText().toString()); } }; request.setContent(content); RestServiceTask task = new RestServiceTask(context); task.execute(request); ``` This code works fine and is calling the web service correctly, my problem is when I want access to the response. In the `AsyncTask` I've created the method `getResponse` but when I use it, it returns a null object because the `AsyncTask` is still in progress, so this code doesn't work: ``` //.... task.execute(request); RestResponse r = new RestResponse(); r = task.getResponse(); ``` `r` will be a null pointer because `AsyncTask` is still downloading data. I've try using this code in the `getResponse` function, but it doesn't work: ``` public RestResponse getResponse() throws InterruptedException { while (getStatus() != AsyncTask.Status.FINISHED); return response; } ``` I thought that with the while loop the thread will wait until the `AsyncTask` finishes, but what I achieved was an infinite loop. So my question is, how could I wait until `AsyncTask` finishes so the `getResponse` method will return the correct result? The best solution is use of the `onPostExecute` method, but because `AsyncTask` is used by many activities I have no clue what to do.