Я создаю приложение новостной ленты и хочу, чтобы можно было извлекать информацию из определенного списка в другой макет, который отображает заголовок, источник, изображение и содержание списка новостей.На главной странице JSON заполнит представление списка заголовком, источником и изображением.Я отправил onItemClickListener, и когда я нажимаю на каждую запись, я хочу, чтобы она открыла эту запись в новом макете для отображения всего содержимого.У меня есть класс, созданный только для извлечения информации JSON, поэтому я не уверен, как использовать это в классе со слушателем onItemClick.Я понимаю putExtra, но я полностью потерян для ввода кода, чтобы передать то, что мне нужно.Ниже приведен код со страницы со списком, а также класс JsonQuery.Спасибо за любую помощь!
TopHeadlinesFragment.java
public class TopHeadlinesFragment extends Fragment
implements LoaderManager.LoaderCallbacks<List<News>> {
public static final String NEWS_FEED_URL =
"https://newsapi.org/v2/top-headlines?country=us&apiKey=a3f791903c1a4163b223dd033563084b";
private static final int NEWS_LOADER_ID = 1;
private NewsAdapter mNewsAdapter;
private NewsAdapterListing mNewsAdapterListing;
public TopHeadlinesFragment(){
// Required empty public constructor
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.news_list, container, false);
mNewsAdapter = new NewsAdapter(getActivity(), new ArrayList<News>());
ListView listView = rootView.findViewById(R.id.list);
listView.setAdapter(mNewsAdapter);
final LoaderManager loaderManager = getLoaderManager();
loaderManager.initLoader(NEWS_LOADER_ID, null, this);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mNewsAdapterListing = new NewsAdapterListing(getActivity(), new ArrayList<News>());
News currentNews = mNewsAdapterListing.getItem(position);
Intent newsArticleDisplayIntent = new Intent(getActivity(), FullArticleListing.class);
startActivity(newsArticleDisplayIntent);
}
});
return rootView;
}
@Override
public Loader<List<News>> onCreateLoader(int id, Bundle args) {
return new NewsLoader(getActivity(), NEWS_FEED_URL);
}
@Override
public void onLoadFinished(Loader<List<News>> loader, List<News> data) {
mNewsAdapter.clear();
if (data != null && !data.isEmpty()){
mNewsAdapter.addAll(data);
}
}
@Override
public void onLoaderReset(Loader<List<News>> loader) {
mNewsAdapter.clear();
}
public static class NewsLoader extends AsyncTaskLoader<List<News>> {
private String[] mUrl;
public NewsLoader(Context context, String... url) {
super(context);
mUrl = url;
}
@Override
protected void onStartLoading() {
forceLoad();
}
@Override
public List<News> loadInBackground() {
if (mUrl.length < 1 || mUrl[0] == null) {
return null;
}
return JsonQueryUtils.fetchNewsData(mUrl[0]);
}
}
}
JsonQueryUtils.java
public class JsonQueryUtils {
/** Contains networking and JSON parsing code **/
private static final String LOG_TAG = "JsonQueryUtils";
private JsonQueryUtils(){
}
/** Helper method to fetch news data and call networking code within method **/
public static List<News> fetchNewsData(String requestUrl){
URL url = createUrl(requestUrl);
String jsonResponse = null;
try{
jsonResponse = makeHttpRequest(url);
} catch (IOException e){
Log.e(LOG_TAG, "Error closing input stream", e);
}
List<News> news = extractNews(jsonResponse);
Log.i(LOG_TAG, "fetchNewsData initialized");
return news;
}
private static List<News> extractNews (final String newsJSON) {
if (TextUtils.isEmpty(newsJSON)) {
return null;
}
List<News> news = new ArrayList<>();
try {
JSONObject jsonNewsObject = new JSONObject(newsJSON);
JSONArray newsArray = jsonNewsObject.getJSONArray("articles");
for (int i = 0; i < newsArray.length(); i++) {
JSONObject currentNews = newsArray.getJSONObject(i);
JSONObject source = currentNews.optJSONObject("source");
String imageUrl = currentNews.getString("urlToImage");
Bitmap newsImage = makeHttpRequest(imageUrl);
String title = currentNews.getString("title");
String sourceName = source.getString("name");
String content = currentNews.getString("content");
news.add(new News(newsImage, title, sourceName));
}
} catch (JSONException e) {
e.printStackTrace();
Log.e(LOG_TAG, "problem with parsing", e);
} catch (IOException e){
e.printStackTrace();
}
return news;
}
/**
* Make an HTTP request to the given imageURL and return a Bitmap as the response.
*/
private static Bitmap makeHttpRequest (String imageUrl) throws IOException {
Bitmap newsImage = null;
if (imageUrl == null){
return newsImage;
}
URL url = createUrl(imageUrl);
HttpURLConnection urlConnection = null;
InputStream inputStream = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoInput(true);
urlConnection.connect();
if (urlConnection.getResponseCode() == 200) {
inputStream = urlConnection.getInputStream();
newsImage = BitmapFactory.decodeStream(inputStream);
}
} catch (IOException e) {
Log.e(LOG_TAG, "Error reading bitmap input stream");
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
inputStream.close();
}
}
return newsImage;
}
/**
* Make an HTTP request to the given 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 early.
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 reading input stream.", e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
inputStream.close();
}
}
return jsonResponse;
}
/**
* Convert the {@link InputStream} into a String which contains the
* whole 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();
}
/** Helper method to create {@link} URL object **/
private static final URL createUrl(String stringUrl) {
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException e) {
Log.e(LOG_TAG, "createUrl: error", e);
}
return url;
}
}