Я пытаюсь сделать довольно простое обновление URL-адреса, который запрашивается. Я изменяю URL в onOptionsItemSelected в зависимости от того, какой пункт в меню выбран. Если я выберу первый пункт, приложение будет отлично работать. Если я выберу второй пункт, приложение вылетает. Зачем? Оба URL-адреса были проверены на правильность. Я считаю, что выбор второго элемента (наивысший рейтинг) вызывает исключение NetworkOnMainThreadException. Мы будем благодарны за любую помощь в отладке.
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.mostPopular) {
FILM_REQUEST_URL = "http://api.themoviedb.org/3/movie/popular?api_key=[MyNetworkKey]";
} else if (item.getItemId() == R.id.highestRated) {
FILM_REQUEST_URL = "http://api.themoviedb.org/3/movie/top_rated?api_key=[MyNetworkKey]";
}
// Clear the adapter of previous film data
mAdapter.clear();
// Get the revised film list
List<Film> films = QueryUtils.fetchFilmData(FILM_REQUEST_URL);
// Populate the adapters data set
if (films != null && !films.isEmpty()) {
mAdapter.addAll(films);
}
return super.onOptionsItemSelected(item);
}
Ошибка Logcat:
Отслеживание ошибок Logcat
QueryUtils.java:
открытый класс QueryUtils {
private QueryUtils() {
}
/** Tag for log messages */
private static final String LOG_TAG = QueryUtils.class.getSimpleName();
/**
* Query TMDb and return a list of {@link Film} objects
*/
public static List<Film> fetchFilmData(String requestUrl) {
// Create a URL object
URL url = createUrl(requestUrl);
//Call HTTP request to URL and get JSON response
String jsonResponse = null;
try {
jsonResponse = makeHttpRequest(url);
} catch (IOException e) {
Log.e(LOG_TAG, "Problem making the HTTP request ", e);
}
// Extract relevant fields from the JSON response and return the list of films
return extractFeatureFromJson(jsonResponse);
}
/**
* Returns new URL object from the given string URL
*/
private static URL createUrl(String stringUrl) {
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException e) {
Log.e(LOG_TAG, "Problem building the URL ", e);
}
return url;
}
/**
* Make HTTP request to the URL and return a String as the response
*/
private static String makeHttpRequest(URL url) throws IOException {
String jsonResponse = "";
// If the URL is null, then return
if (url == null) {
return jsonResponse;
}
HttpURLConnection urlConnection = null;
InputStream inputStream = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setReadTimeout(10000 /* milliseconds */);
urlConnection.setConnectTimeout(15000 /* milliseconds */);
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// If the request was successful (response code 200),
// then read the input stream and parse the response.
if (urlConnection.getResponseCode() == 200) {
inputStream = urlConnection.getInputStream();
jsonResponse = readFromStream(inputStream);
} else {
Log.e(LOG_TAG, "Error response code: " + urlConnection.getResponseCode());
}
} catch (IOException e) {
Log.e(LOG_TAG, "Problem retrieving the movie JSON results ", e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
// Closing the input stream could throw an IOException, which is why
// the makeHttpRequest(URL url) method signature specifies than an IOException
// could be thrown
inputStream.close();
}
}
return jsonResponse;
}
/**
* Convert the {@link InputStream} into a String that contains JSON
* response from the server
*/
private static String readFromStream(InputStream inputStream) throws IOException {
StringBuilder output = new StringBuilder();
if (inputStream != null) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, Charset.forName("UTF-8"));
BufferedReader reader = new BufferedReader(inputStreamReader);
String line = reader.readLine();
while (line != null) {
output.append(line);
line = reader.readLine();
}
}
return output.toString();
}
/**
* Return a list of {@link Film} objects that has been built up from
* parsing the given JSON response
*/
private static List<Film> extractFeatureFromJson(String filmJSON) {
// If the JSON string is empty or null, then return
if (TextUtils.isEmpty(filmJSON)) {
return null;
}
// Create an empty ArrayList that we can start adding films to
List<Film> films = new ArrayList<>();
// Try to parse the JSON response string. If there's a problem with the way the JSON
// is formatted, a JSONException exception object will be thrown
try {
// Create a JSONObject from the JSON response string
JSONObject baseJsonResponse = new JSONObject(filmJSON);
// Extract the JSONArray associated with the key called "results",
// which represents a list of films
JSONArray filmArray = baseJsonResponse.getJSONArray("results");
// For each movie in the movieArray, create an {@link Film} object
for (int i = 0; i < filmArray.length(); i++) {
// Get a single movie at position i within the list of movies
JSONObject currentFilm = filmArray.getJSONObject(i);
// Extract the value for individual keys from JSONObject results
int voteCount = currentFilm.getInt("vote_count");
long voteAverage = currentFilm.getLong("vote_average");
String title = currentFilm.getString("title");
long popularity = currentFilm.getLong("popularity");
String posterUrl = "http://image.tmdb.org/t/p/w185" + currentFilm.getString("poster_path");
String overview = currentFilm.getString("overview");
String releaseDate = currentFilm.getString("release_date");
// Create a new {@link Film} object with the vote count, vote average, title,
// popularity, poster path, overview, and release date from the JSON response
Film film = new Film(voteCount, voteAverage, title, popularity, posterUrl,
overview, releaseDate);
// Add the new {@link Film} to the list of movies
films.add(film);
}
} catch (JSONException e) {
// If an error is thrown when executing any of the above statements in the "try" block,
// catch the exception here, so the app doesn't crash. Print a log message
// with the message from the exception
Log.e("QueryUtils", "Problem parsing the TMDb JSON results", e);
}
// Return the list of films
return films;
}
}