Android Volley Null Pointer Exception

Estoy intentando convertir un tutorial previamente basado en actividad en un fragmento, pero sigo corriendo en el error NullPointerException en mi adaptador.

El tutorial se basa en esto y he adelgazado el constructor para el adaptador porque solía llamar a una actividad.

• LoganSquare analiza la biblioteca de Android: retroalimentación, puntos de referencia, pros y contras
• ASync Task no se puede ejecutar dos veces
• Cómo obtener respuesta como String utilizando retrofit sin utilizar GSON o cualquier otra biblioteca en android
• ¿Debo usar XML o JSON como un formato de datos en las aplicaciones de Android?
• Volley Android Cómo enviar solicitud con los encabezados de autenticación y el objeto Json en el cuerpo

Hay una solución posible aquí, pero nadie sabe cómo proceder con la misma pregunta posible.

Quiero convertir todo a un Fragmento de trabajo. Por favor, hágamelo saber si necesita más información de mí.

Clase convertida principal:

public class mainViewController2 extends Fragment { private static final String TAG = mainViewController2.class.getSimpleName(); private ListView listView; private FeedListAdapter listAdapter; private List<FeedItem> feedItems; private String URL_FEED = "http://api.androidhive.info/feed/feed.json"; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.mainviewcontroller2_fragment, container, false); listView = (ListView) v.findViewById(R.id.list); feedItems = new ArrayList<FeedItem>(); //where the error shows up? listAdapter = new FeedListAdapter(feedItems); listView.setAdapter(listAdapter); // We first check for cached request Cache cache = AppController.getInstance().getRequestQueue().getCache(); Entry entry = cache.get(URL_FEED); if (entry != null) { // fetch the data from cache try { String data = new String(entry.data, "UTF-8"); try { parseJsonFeed(new JSONObject(data)); } catch (JSONException e) { e.printStackTrace(); } } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } else { // making fresh volley request and getting json JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET, URL_FEED, null, new Response.Listener<JSONObject>() { @Override public void onResponse(JSONObject response) { VolleyLog.d(TAG, "Response: " + response.toString()); if (response != null) { parseJsonFeed(response); } } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { VolleyLog.d(TAG, "Error: " + error.getMessage()); } }); // Adding request to volley request queue AppController.getInstance().addToRequestQueue(jsonReq); } return v; } /** * Parsing json reponse and passing the data to feed view list adapter * */ private void parseJsonFeed(JSONObject response) { try { JSONArray feedArray = response.getJSONArray("feed"); for (int i = 0; i < feedArray.length(); i++) { JSONObject feedObj = (JSONObject) feedArray.get(i); FeedItem item = new FeedItem(); item.setId(feedObj.getInt("id")); item.setName(feedObj.getString("name")); // Image might be null sometimes String image = feedObj.isNull("image") ? null : feedObj .getString("image"); item.setImge(image); item.setStatus(feedObj.getString("status")); item.setProfilePic(feedObj.getString("profilePic")); item.setTimeStamp(feedObj.getString("timeStamp")); // url might be null sometimes String feedUrl = feedObj.isNull("url") ? null : feedObj .getString("url"); item.setUrl(feedUrl); feedItems.add(item); } // notify data changes to list adapater listAdapter.notifyDataSetChanged(); } catch (JSONException e) { e.printStackTrace(); } } } 

FeedListAdapter:

  public class FeedListAdapter extends BaseAdapter { private Activity activity; private LayoutInflater inflater; private List<FeedItem> feedItems; Context context; ImageLoader imageLoader; public FeedListAdapter(Context ctx,List<FeedItem> feedItems) { this.context= ctx; this.feedItems = feedItems; imageLoader = AppController.getInstance().getImageLoader(); inflater = LayoutInflater.from(context); } @Override public int getCount() { return feedItems.size(); } @Override public Object getItem(int location) { return feedItems.get(location); } @Override public long getItemId(int position) { return position; } @SuppressLint("InflateParams") @Override public View getView(int position, View convertView, ViewGroup parent) { if (inflater == null) inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); if (convertView == null) convertView = inflater.inflate(R.layout.feed_item, null); if (imageLoader == null) imageLoader = AppController.getInstance().getImageLoader(); TextView name = (TextView) convertView.findViewById(R.id.name); TextView timestamp = (TextView) convertView .findViewById(R.id.timestamp); TextView statusMsg = (TextView) convertView .findViewById(R.id.txtStatusMsg); TextView url = (TextView) convertView.findViewById(R.id.txtUrl); NetworkImageView profilePic = (NetworkImageView) convertView .findViewById(R.id.profilePic); FeedImageView feedImageView = (FeedImageView) convertView .findViewById(R.id.feedImage1); FeedItem item = feedItems.get(position); name.setText(item.getName()); // Converting timestamp into x ago format CharSequence timeAgo = DateUtils.getRelativeTimeSpanString( Long.parseLong(item.getTimeStamp()), System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS); timestamp.setText(timeAgo); // Chcek for empty status message if (!TextUtils.isEmpty(item.getStatus())) { statusMsg.setText(item.getStatus()); statusMsg.setVisibility(View.VISIBLE); } else { // status is empty, remove from view statusMsg.setVisibility(View.GONE); } // Checking for null feed url if (item.getUrl() != null) { url.setText(Html.fromHtml("<a href=\"" + item.getUrl() + "\">" + item.getUrl() + "</a> ")); // Making url clickable url.setMovementMethod(LinkMovementMethod.getInstance()); url.setVisibility(View.VISIBLE); } else { // url is null, remove from the view url.setVisibility(View.GONE); } // user profile pic profilePic.setImageUrl(item.getProfilePic(), imageLoader); // Feed image if (item.getImge() != null) { feedImageView.setImageUrl(item.getImge(), imageLoader); feedImageView.setVisibility(View.VISIBLE); feedImageView .setResponseObserver(new FeedImageView.ResponseObserver() { @Override public void onError() { } @Override public void onSuccess() { } }); } else { feedImageView.setVisibility(View.GONE); } return convertView; } } 

Errores de LogCat:

 09-06 02:51:55.823: E/AndroidRuntime(8279): FATAL EXCEPTION: main 09-06 02:51:55.823: E/AndroidRuntime(8279): Process: com.rynovation.kline, PID: 8279 09-06 02:51:55.823: E/AndroidRuntime(8279): java.lang.NullPointerException 09-06 02:51:55.823: E/AndroidRuntime(8279): at androidFeedClasses.FeedListAdapter.<init>(FeedListAdapter.java:35) 09-06 02:51:55.823: E/AndroidRuntime(8279): at com.rynovation.kline.mainViewController2.onCreateView(mainViewController2.java:51) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.Fragment.performCreateView(Fragment.java:1700) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:890) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.BackStackRecord.run(BackStackRecord.java:684) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1453) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.FragmentManagerImpl$1.run(FragmentManager.java:443) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.os.Handler.handleCallback(Handler.java:733) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.os.Handler.dispatchMessage(Handler.java:95) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.os.Looper.loop(Looper.java:146) 09-06 02:51:55.823: E/AndroidRuntime(8279): at android.app.ActivityThread.main(ActivityThread.java:5487) 09-06 02:51:55.823: E/AndroidRuntime(8279): at java.lang.reflect.Method.invokeNative(Native Method) 09-06 02:51:55.823: E/AndroidRuntime(8279): at java.lang.reflect.Method.invoke(Method.java:515) 09-06 02:51:55.823: E/AndroidRuntime(8279): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283) 09-06 02:51:55.823: E/AndroidRuntime(8279): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099) 09-06 02:51:55.823: E/AndroidRuntime(8279): at dalvik.system.NativeStart.main(Native Method) 

  <application android:name="<package-name>.app.AppController" // <-- this one android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme"> 

 listView = (ListView) getActivity().findViewById(R.id.list); 

 listView = (ListView)v.findViewById(R.id.list); 

 listAdapter = new FeedListAdapter(getActivity(),feedItems); 

  ImageLoader imageLoader; public FeedListAdapter(Context ctx,List<FeedItem> feedItems) { this.context= ctx; this.feedItems = feedItems; imageLoader = AppController.getInstance().getImageLoader() } 

 @Override protected Map<String, String> getParams() { Map<String, String> params = new HashMap<String, String>(); if(paramValue!= null) params.put("paramKey", paramValue); else params.put("paramKey", "anyOtherDefaultValue"); return params; }