如何等待Weather API响应

Question

这里，Toast显示来自API的正确天气响应，但是当我将此响应返回给调用函数时，它给出null。实际上，来自API的响应需要一些时间，并且在从API获得实际响应之前返回null。

public String weatherStatus(String city) {

    weatherMap.getCityWeather(city, new WeatherCallback() {
        @Override
        public void success(WeatherResponseModel weatherResponseModel) {
            Weather weather[] = weatherResponseModel.getWeather();
            weatherMain = weather[0].getMain();
            Toast.makeText(this,weatherMain,Toast.LENGTH_LONG).show();
        }

        @Override
        public void failure(String s) {

        }
    });

    return weatherMain;
}

那么，如何等待Weather API的响应？

Answer 1

我不知道您是如何尝试在AsyncTask中实现此功能的，但您可以按照以下方法进行操作。

public class RestManager extends AsyncTask<Void, Void, WeatherResponseModel> implements WeatherCallback{

        private int mStatus;
        private WeatherResponseModel mModel;
        private String mError;
        private Context mContext;

        public RestManager(Context context){
               mContext = context;
        }

        @Override
        protected WeatherResponseModel doInBackground(Void... params) {
            WeatherMap weatherMap = new WeatherMap(mContext, OWM_API_KEY);
            weatherMap.getCityWeather(city, this);
            mStatus = 0;
            while(mStatus==0);//wait for response..
            return mModel;
        }

        @Override
        protected void onPostExecute(WeatherResponseModel weatherResponseModel) {
            super.onPostExecute(weatherResponseModel);
            if(mStatus==1){
                //Success
                Weather weather[] = weatherResponseModel.getWeather();
                weatherMain = weather[0].getMain();
             Toast.makeText(this,weatherMain,Toast.LENGTH_LONG).show();
            }else{
                //Error
            }
        }

        @Override
        public void success(WeatherResponseModel weatherResponseModel) {
            mStatus = 1;
            mModel =  weatherResponseModel;
        }

        @Override
        public void failure(String s) {
            mStatus = -1;
            mError=s;
        }

}