[整理]Android開發（二）-Weather App

private class WeatherData{
private String _weatherDescription;
private Integer _currentTemperature;
private Integer _LowTemperature;
private Integer _highTemperature;

public WeatherData(String weatherDescription,Integer currentTemperature, Integer LowTemperature, Integer highTemperature){
        _weatherDescription = weatherDescription;
        _currentTemperature = currentTemperature;
        _LowTemperature = LowTemperature;
        _highTemperature = highTemperature;
    }

    public String getWeatherDescription(){
        return _weatherDescription;
    }

    public Integer getCurrentTemperature(){
        return _currentTemperature;
    }

    public Integer getLowTemperature(){
        return _LowTemperature;
    }

    public Integer getHighTemperature(){
        return _highTemperature;
    }
}

//異步獲取天氣數據，並更新主UI線程
private class HttpRequestAsyncTask extends AsyncTask{

    private WeatherData loadWeatherData(String requestUrl){
        WeatherData weatherData = null;
        String dataResponse = null;

        //經過API，獲取天氣數據
        try{
            URL url = new URL(requestUrl);
            HttpURLConnection conn = (HttpURLConnection)url.openConnection();

            //conn.setConnectTimeout(10000);
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setUseCaches(false);
            conn.setRequestMethod("GET");
            conn.setRequestProperty("apikey","XXX");

            conn.connect();

            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
            StringBuffer buffer = new StringBuffer();
            String lineBuffer = null;

            while((lineBuffer=reader.readLine()) != null){
                buffer.append(lineBuffer);
            }

            reader.close();
            conn.disconnect();

            dataResponse = buffer.toString();
        }
        catch (Exception ex){
            ex.printStackTrace();
            System.out.println("error->"+ex.getMessage());
        }

        //解析對返回的json數據
        /** api return value
         *  {
                 "errNum": 0,
                 "errMsg": "success",
                 "retData": {
                     "city": "上海",
                     "pinyin": "shanghai",
                     "citycode": "101020100",
                     "date": "15-06-03",
                     "time": "11:00",
                     "postCode": "200000",
                     "longitude": 121.445,
                     "latitude": 31.213,
                     "altitude": "19",
                     "weather": "陰",
                     "temp": "25",
                     "l_tmp": "20",
                     "h_tmp": "25",
                     "WD": "東北風",
                     "WS": "微風(<10m/h)",
                     "sunrise": "04:50",
                     "sunset": "18:54"
                 }
             }
         * */

        try{
            JSONTokener jsonParser = new JSONTokener(dataResponse);
            JSONObject weatherInfo = (JSONObject)jsonParser.nextValue();
            int returnValue =  weatherInfo.getInt("errNum");

            if(returnValue != 0){
                System.out.println( "api get error->" + returnValue);
            }
            else{
                JSONObject jsonData = weatherInfo.getJSONObject("retData");
                weatherData = new WeatherData(jsonData.getString("weather"),jsonData.getInt("temp"),jsonData.getInt("l_tmp"),jsonData.getInt("h_tmp"));
            }
        }
        catch (JSONException ex){
            ex.printStackTrace();
            System.out.println( "api get error->" + ex.getMessage());
        }

        return weatherData;
    }

    @Override
    protected Object doInBackground(Object[] params) {
        String requestUrl = params[0].toString();
        return this.loadWeatherData(requestUrl);
    }

    @Override
    protected void onPostExecute(Object o) {

        if(o==null){
            AlertDialog.Builder alertBuilder = new AlertDialog.Builder(MainActivity.this);
            alertBuilder.setTitle(R.string.alert_title_load_weather_failed)
                    .setMessage(R.string.alert_message_load_weather_failed);

            alertBuilder.create();
        }
        else{
            //super.onPostExecute(o);
            WeatherData weatherData = (WeatherData)o;

            //更新UI
            CurrentTempratureTextView.setText(weatherData.getCurrentTemperature()+"℃");
        }
    }
}