is it possible to make a call back to an outer nested class in java?

Question

here's an example of what I'm trying to do

 public class BookModel {

        private void update_method() {
            get_info task = new get_info(this)
            task.exicute(some args); 
        }

        public void finishedCallback(some_return_type result) {
        // do some stuff when finsiehd. 
        }


    class get_info extends AsyncTask<HashMap<String, String>, Void, dataType>
    {
        private BookModel bookModel; 

        public get_info ( BookModel reset) {
            bookModel = reset; 
        }

        @Override
        protected dataType doInBackground(arg...)
                        some procscessing. 
        }

        protected void onPostExecute(dataType result) {
            bookModel.finishedCallback(result);
        }
    }
    }

How can i get this callback system to work... I tried using an inteface as well, but it did not work. I think it's because you need 3 classes with an interface (correct me if I'm wrong). also I'm open to any suggestions, but Ideally I would like to keep this functionality within the same class if possible. any help with this would be greatly appreciated.

Answer 1

try this.

this is worked for me.

 public class BookModel implements get_info.xyz {

    private void update_method() {
        get_info task = new get_info(this);
        task.exicute(some args); 
    }

    public void finishedCallback(String result) {
    // do some stuff when finsiehd. 
    }

 }
//----------------------------------
class get_info extends AsyncTask<HashMap<String, String>, Void, dataType>
{


    private xyz bookModel; 
    public interface xyz
    {
       void finishedCallback(String str);
    }
    public get_info ( xyz reset) {
        bookModel = reset; 
    }

    @Override
    protected dataType doInBackground(arg...)
                    some procscessing. 
    }

    protected void onPostExecute(dataType result) {
        bookModel.finishedCallback(result);
    }
}