Json com android

Boa noite,

Sou novo em programação android e estou precisando de ajuda, preciso fazer um apk que conecte a um webservice via json. O apk que estou fazendo é de horoscopo, e encontrei o Json já pronto e online. Só que minha aplicação fecha ao atualizar as informações alguém poderia me informar o que ta de errado em meu código e me ajudar.

Segue o AsynTask para conectar com o serviço e o link do Json ja pronto é este: http://developers.agenciaideias.com.br/horoscopo.

public class FetchWeatherTask extends AsyncTask<String, Void, String[]> {

@Override

protected String[] doInBackground(String... params) {

 HttpURLConnection urlConnection = null;

 BufferedReader reader = null;

 String forecastJsonStr = null;

 String format = "json";

 String units = "metric";

 int numDays = 1;

 try {

 final String FORECAST_BASE_URL =

 "[http://developers.agenciaideias.com.br/horoscopo/json";](http://developers.agenciaideias.com.br/horoscopo/json)

 final String QUERY_PARAM = "q";

 final String FORMAT_PARAM = "mode";

 final String UNITS_PARAM = "units";

 final String DAYS_PARAM = "cnt";

 Uri uri = Uri.parse(FORECAST_BASE_URL)

 .buildUpon()

 .appendQueryParameter(QUERY_PARAM, params[0])

 .appendQueryParameter(FORMAT_PARAM, format)

 .appendQueryParameter(UNITS_PARAM, units)

 .appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))

 .build();

 URL url = new URL(uri.toString());

 // Construct the URL for the OpenWeatherMap query

 // Possible parameters are available at OWM's forecast API page, at

 // [http://openweathermap.org/API#forecast](http://openweathermap.org/API#forecast)

 // Create the request to OpenWeatherMap, and open the connection

 urlConnection = (HttpURLConnection) url.openConnection();

 urlConnection.setRequestMethod("GET");

 urlConnection.connect();

 // Read the input stream into a String

 InputStream inputStream = urlConnection.getInputStream();

 StringBuffer buffer = new StringBuffer();

 if (inputStream == null) {

 // Nothing to do.

 return null;

 }

 reader = new BufferedReader(new InputStreamReader(inputStream));

 String line;

 while ((line = reader.readLine()) != null) {

 // Since it's JSON, adding a newline isn't necessary (it won't affect parsing)

 // But it does make debugging a *lot* easier if you print out the completed

 // buffer for debugging.

 buffer.append(line + "\n");

 }

 if (buffer.length() == 0) {

 // Stream was empty. No point in parsing.

 forecastJsonStr = null;

 }

 forecastJsonStr = buffer.toString();

 } catch (IOException e) {

 Log.e("PlaceholderFragment", "Error ", e);

 // If the code didn't successfully get the weather data, there's no point in attempting

 // to parse it.

 forecastJsonStr = null;

 } finally {

 if (urlConnection != null) {

 urlConnection.disconnect();

 }

 if (reader != null) {

 try {

 reader.close();

 } catch (final IOException e) {

 Log.e("PlaceholderFragment", "Error closing stream", e);

 }

 }

 }

 String[] returnStrs = new String[0];

 try {

 return TesteJson.getSignosFromJson(

 forecastJsonStr, numDays);

 } catch (JSONException e) {

 e.printStackTrace();

 }

 return returnStrs;

 }

 }

E aqui tento pegar as informações do Json;

public class TesteJson {

private static String getReadableDateString(long time){

 Date date = new Date(time * 1000);

 SimpleDateFormat format = new SimpleDateFormat("E, MMM d");

 return format.format(date).toString();

 }

 public static String[] getSignosFromJson(String forecastJsonStr, int numDays)

 throws JSONException {

 final String signos = "signos";

 final String nome = "nome";

 final String data = "data";

 final String msg = "msg";

 final String periodo = "periodo";

 JSONObject forecastJson = new JSONObject(forecastJsonStr);

 JSONArray SignosArray = forecastJson.getJSONArray(signos);

 String[] resultSet = new String[numDays];

 for(int i =0; i < SignosArray.length(); i++){

 String dia;

 String nomeSigno;

 String mensagem;

 String per;

 JSONObject dayForecast = new JSONObject(String.valueOf(i));

 long dataTime = dayForecast.getLong(data);

 dia = getReadableDateString(dataTime);

 JSONObject signoNome = dayForecast.getJSONObject(nome);

 nomeSigno = SignosArray.getString(Integer.parseInt(nome));

 JSONObject msgsigno = dayForecast.getJSONObject(msg);

 mensagem = SignosArray.getString(Integer.parseInt(msg));

 JSONObject periodoJson = dayForecast.getJSONObject(periodo);

 per = SignosArray.getString(Integer.parseInt(periodo));

 resultSet* = dia + "\n" + nomeSigno + "\n" + mensagem;*

}

return resultSet;

}

}