How to get the result of OnPostExecute() to main activity because AsyncTask is a separate class?

Question

I have this two classes. My main Activity and the one that extends the AsyncTask, Now in my main Activity I need to get the result from the OnPostExecute(

Answer 1

Probably going overboard a bit but i provided call backs for both the execution code and the results. obviously for thread safety you want to be careful what you access in your execution callback.

The AsyncTask implementation:

public class AsyncDbCall extends AsyncTask
{
    public interface ExecuteCallback
    {
        public R execute(E executeInput);
    }
    public interface PostExecuteCallback
    {
        public void finish(R result);
    }

    private PostExecuteCallback _resultCallback = null;
    private ExecuteCallback _executeCallback = null;


    AsyncDbCall(ExecuteCallback executeCallback, PostExecuteCallback postExecuteCallback)
    {
        _resultCallback = postExecuteCallback;
        _executeCallback = executeCallback;
    }

    AsyncDbCall(ExecuteCallback executeCallback)
    {
        _executeCallback = executeCallback;
    }

    @Override
    protected ResultType doInBackground(final ExecuteType... params)
    {
        return  _executeCallback.execute(params[0]);
    }

    @Override
    protected void onPostExecute(ResultType result)
    {
        if(_resultCallback != null)
            _resultCallback.finish(result);
    }
}

A callback:

 AsyncDbCall.ExecuteCallback updateDeviceCallback = new 
 AsyncDbCall.ExecuteCallback()
    {
        @Override
        public Device execute(Device device)
        {
            deviceDao.updateDevice(device);
            return device;
        }
    };

And finally execution of the async task:

 new AsyncDbCall<>(addDeviceCallback, resultCallback).execute(device);