I am using this Tutorial and its sourcecodes to make listview in android. I had implemented using this tutorial but during updating the setListAdapter i cannot update the listview dynamically.
I have gone through many stackoverflow questions and they are giving adapter.notifyDataSetChanged() as the solution. But i am unable to implement it in AsyncTask.
ItemListFragment.java
public class ItemListFragment extends ListFragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = super.onCreateView(inflater, container, savedInstanceState);
setListAdapter(new ItemAdapter(getActivity(), setArray(getActivity())));
return v;
}
public ArrayList<Item> setArray(Context context)
{
ArrayList<Item> items = new ArrayList<Item>();
Realm realm = Realm.getInstance(context);
RealmResults<Books> bs = realm.where(Books.class).findAll();
for (int i = 0; i < bs.size(); i++) {
Bitmap url = BitmapFactory.decodeFile(bs.get(i).getCover());
String title = bs.get(i).getName();
String description = bs.get(i).getAuthor();
Item item = new Item(url, title, description);
items.add(item);
}
realm.close();
return items;
}
}
ItemAdapter.java
public class ItemAdapter extends ArrayAdapter<Item> {
public ItemAdapter(Context context, List<Item> items) {
super(context, 0, items);
}
public View getView(int position, View convertView, ViewGroup parent)
{
ItemView itemView = (ItemView) convertView;
if (null == itemView)
{
itemView = ItemView.inflate(parent);
}
itemView.setItem(getItem(position));
return itemView;
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
if (BuildConfig.DEBUG)
ViewServer.get(this).addWindow(this);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
else if (id == R.id.update) {
Update update = new Update(getApplicationContext(), MainActivity.this);
update.execute();
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onDestroy() {
super.onDestroy();
if (BuildConfig.DEBUG)
ViewServer.get(this).removeWindow(this);
}
#Override
protected void onResume() {
super.onResume();
if (BuildConfig.DEBUG)
ViewServer.get(this).setFocusedWindow(this);
}
}
Update.java
public class Update extends AsyncTask<Void,Void,Void>{
private Context context;
public Activity activity;
public Update(Context context, Activity activity)
{
this.context = context;
this.activity = activity;
}
#Override
protected Void doInBackground(Void... params) {
ServerAddress = context.getString(R.string.ServerAddress);
StringExtras = context.getString(R.string.CheckBook);
Realm realm = null;
try {
URL url = new URL(ServerAddress + StringExtras);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("GET");
httpURLConnection.setRequestProperty("Content-length", "0");
httpURLConnection.setUseCaches(false);
httpURLConnection.setAllowUserInteraction(false);
httpURLConnection.setConnectTimeout(1000);
httpURLConnection.setReadTimeout(1000);
httpURLConnection.connect();
int responseCode = httpURLConnection.getResponseCode();
Log.i("Response Code",responseCode+"");
BufferedReader br = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream()));
String InputLine;
StringBuilder response = new StringBuilder();
while ((InputLine = br.readLine()) != null)
{
response.append(InputLine);
}
br.close();
httpURLConnection.disconnect();
Log.i("Response Data", response.toString());
GsonBuilder gsonBuilder = new GsonBuilder();
Gson gson = gsonBuilder.create();
JSONArray array = new JSONArray(response.toString());
//booksList = Arrays.asList(books);
//JSONArray jsonArray = object.getJSONArray("cover");
realm = Realm.getInstance(context);
for (int i=0; i< array.length(); i++ ) {
JSONObject object = array.getJSONObject(i);
Books books = gson.fromJson(object.toString(), Books.class);
Publish(books, realm);
}
}
catch (Exception e) {
e.printStackTrace();
}
finally {
if (realm != null){
realm.close();
}
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
//i want to call the setarray that contains my database data which has been updated on `doinbackground` and update the listview accordingly.
//The below codes are just the codes that i have tried but what should i do to update the listview.
activity.runOnUiThread(new Runnable() {
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#Override
public void run() {
ItemListFragment activity1 = new ItemListFragment();
ArrayList<Item> arrayList = activity1.setArray(context);
List<Item> list = new ArrayList<Item>();
int i = 0;
for (Item item : arrayList)
{
list.add(arrayList.get(i));
i++;
}
activity1.arrayAdapter.addAll(list);
activity1.arrayAdapter.notifyDataSetChanged();
}
});
}
I am trying to update the listview from postexcution. So, how can i update the view through it.
Error From AsyncTask
just incase you need but it's not the problem
8-30 16:31:47.976 1167-1167/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
at np.com.thefourthgeneration.Update$1.run(Update.java:124)
at android.app.Activity.runOnUiThread(Activity.java:4673)
at np.com.thefourthgeneration.Update.onPostExecute(Update.java:108)
at np.com.thefourthgeneration.Update.onPostExecute(Update.java:34)
at android.os.AsyncTask.finish(AsyncTask.java:631)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
layout/activity_list
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
layout/list_fragment
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ListView
android:id="#+id/listView"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
MainActivity
public class MainActivity extends AppCompatActivity
{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
FragmentManager fm = getFragmentManager();
itemListFragment = (ItemListFragment) fm.findFragmentByTag(ItemListFragment.class.getSimpleName());
if (itemListFragment == null) {
itemListFragment = new ItemListFragment();
FragmentTransaction fragmentTransaction = fm.beginTransaction();
fragmentTransaction.replace(R.id.content_frame, itemListFragment, ItemListFragment.class.getSimpleName());
fragmentTransaction.commit();
}
if (BuildConfig.DEBUG) {
ViewServer.get(this).addWindow(this);
}
}
#Override
protected void onDestroy() {
super.onDestroy();
if (BuildConfig.DEBUG) {
ViewServer.get(this).removeWindow(this);
}
}
#Override
protected void onResume() {
super.onResume();
if (BuildConfig.DEBUG) {
ViewServer.get(this).setFocusedWindow(this);
}
}
}
ItemListFragment
public class ItemListFragment extends Fragment
{
private ListView listView;
private ItemAdapter itemAdapter;
private ArrayList<Item> itemArrayList = new ArrayList<>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.list_fragment, container, false);
itemAdapter = new ItemAdapter(getActivity(), itemArrayList);
listView = (ListView) view.findViewById(R.id.listView);
listView.setAdapter(itemAdapter);
return view;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_main, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
return true;
case R.id.update:
new Update(getActivity()).execute();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public class Update extends AsyncTask<Void, Void, Void>
{
private Context context;
public Update(Context context) {
this.context = context;
}
#Override
protected Void doInBackground(Void... params) {
ServerAddress = context.getString(R.string.ServerAddress);
StringExtras = context.getString(R.string.CheckBook);
Realm realm = null;
try {
URL url = new URL(ServerAddress + StringExtras);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("GET");
httpURLConnection.setRequestProperty("Content-length", "0");
httpURLConnection.setUseCaches(false);
httpURLConnection.setAllowUserInteraction(false);
httpURLConnection.setConnectTimeout(1000);
httpURLConnection.setReadTimeout(1000);
httpURLConnection.connect();
int responseCode = httpURLConnection.getResponseCode();
Log.i("Response Code", responseCode + "");
BufferedReader br = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream()));
String InputLine;
StringBuilder response = new StringBuilder();
while ((InputLine = br.readLine()) != null) {
response.append(InputLine);
}
br.close();
httpURLConnection.disconnect();
Log.i("Response Data", response.toString());
GsonBuilder gsonBuilder = new GsonBuilder();
Gson gson = gsonBuilder.create();
JSONArray array = new JSONArray(response.toString());
//booksList = Arrays.asList(books);
//JSONArray jsonArray = object.getJSONArray("cover");
realm = Realm.getInstance(context);
for (int i = 0; i < array.length(); i++) {
JSONObject object = array.getJSONObject(i);
Books books = gson.fromJson(object.toString(), Books.class);
Publish(books, realm);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (realm != null) {
realm.close();
}
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
itemArrayList.clear();
itemArrayList.addAll(getArray(context));
itemAdapter.notifyDataSetChanged();
}
public ArrayList<Item> getArray(Context context) {
ArrayList<Item> items = new ArrayList<Item>();
Realm realm = Realm.getInstance(context);
RealmResults<Books> bs = realm.where(Books.class).findAll();
for (int i = 0; i < bs.size(); i++) {
Bitmap url = BitmapFactory.decodeFile(bs.get(i).getCover());
String title = bs.get(i).getName();
String description = bs.get(i).getAuthor();
Item item = new Item(url, title, description);
items.add(item);
}
realm.close();
return items;
}
}
public class ItemAdapter extends ArrayAdapter<Item>
{
public ItemAdapter(Context context, List<Item> items) {
super(context, 0, items);
}
public View getView(int position, View convertView, ViewGroup parent) {
ItemView itemView = (ItemView) convertView;
if (null == itemView) {
itemView = ItemView.inflate(parent);
}
itemView.setItem(getItem(position));
return itemView;
}
}
}
Its not the 100% work code, because i dont fully understand all structures (like Realm) and I dont test it, but its the main idea.
Related
I've tried to look for a solution but I have not been able to find one with my specific situation. I'm using a recyclerview with GSON and I'm getting the message of skipping layout. My code looks correct but I know I should set an empty adapter in the onCreateView section. I'm not sure how to exactly do that. Any help will be appreciated. My fragment activity is below.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_weather_app, container, false);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
mRecyclerView.addItemDecoration(new DividerItemDecoration(mRecyclerView.getContext(), DividerItemDecoration.VERTICAL));
new GetWeatherAync().execute(getActivity());
return view;
}
private class GetWeatherAync extends AsyncTask<Context, Void,
List<ForecastWeatherList>> {
private String TAG = GetWeatherAync.class.getSimpleName();
private Context mContext;
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected List<ForecastWeatherList> doInBackground(Context...params) {
mContext = params[0];
return getWeatherFromServer();
}
#Override
protected void onPostExecute(List<ForecastWeatherList> result) {
super.onPostExecute(result);
if (result != null) {
Log.e(TAG, "populate UI recycler view with gson converted data");
RecyclerViewAdapter weatherRecyclerViewAdapter = new RecyclerViewAdapter(result, mContext);
mRecyclerView.setAdapter(weatherRecyclerViewAdapter);
}
}
}
public List<ForecastWeatherList> getWeatherFromServer(){
String serviceUrl = "http://api.openweathermap.org/data/2.5/forecast?q=" + searchView + api_key;
URL url = null;
try {
url = new URL(serviceUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setDoOutput(true);
connection.setConnectTimeout(4000);
connection.setReadTimeout(4000);
connection.connect();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
//pass buffered reader to convert json to javaobject using gson
return convertJsonToObject(bufferedReader);
}catch (Exception e){
}
return null;
}
public List<ForecastWeatherList> convertJsonToObject(BufferedReader bufferedReader){
final Gson gson = new Gson();
//pass root element type to fromJson method along with input stream
ForecastWeatherListWrapper weatherWrapper = gson.fromJson(bufferedReader,ForecastWeatherListWrapper.class);
List<ForecastWeatherList> weatherlst = weatherWrapper.getforecastWeatherLists();
return weatherlst;
}
EDIT:
So I've implemented the following changes:
Listener Interface.
import com.ksburneytwo.weathertest.ForecastWeather.ForecastWeatherList;
import java.util.List;
public interface Listener {
void afterSearch(List<ForecastWeatherList> result);
}
Fragment:
public static WeatherAppFragment newInstance(String param1, String param2) {
WeatherAppFragment fragment = new WeatherAppFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_weather_app, container, false);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
mRecyclerView.addItemDecoration(new DividerItemDecoration(mRecyclerView.getContext(), DividerItemDecoration.VERTICAL));
new GetWeatherAync().execute(getActivity());
return view;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu, menu);
MenuItem searchItem = menu.findItem(R.id.menu_search);
SearchManager searchManager = (SearchManager) getActivity().getSystemService(Context.SEARCH_SERVICE);
if (searchItem != null) {
searchView = (SearchView) searchItem.getActionView();
}
if (searchView != null) {
searchView.setSearchableInfo(searchManager.getSearchableInfo(getActivity().getComponentName()));
queryTextListener = new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextChange(String newText) {
Log.i("onQueryTextChange", newText);
return true;
}
#Override
public boolean onQueryTextSubmit(String query) {
Log.i("onQueryTextSubmit", query);
return true;
}
};
searchView.setOnQueryTextListener(queryTextListener);
}
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public void afterSearch(List<ForecastWeatherList> result) {
mRecyclerView.setAdapter(new RecyclerViewAdapter(result, mRecyclerView.getContext()));
}
private static class GetWeatherAync extends AsyncTask<Context, Void, List<ForecastWeatherList>> {
private String TAG = GetWeatherAync.class.getSimpleName();
private final String serviceUrl;
private Context mContext;
private Listener listener;
GetWeatherAync(Listener listener,String searchView, String api_key) {
this.listener = listener;
this.serviceUrl = "http://api.openweathermap.org/data/2.5/forecast?q=" + searchView + api_key;
}
#Override
protected List<ForecastWeatherList> doInBackground(Context...params) {
try {
URL url = new URL(serviceUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setDoOutput(true);
connection.setConnectTimeout(4000);
connection.setReadTimeout(4000);
connection.connect();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
ForecastWeatherListWrapper weatherWrapper = new Gson().fromJson(bufferedReader, ForecastWeatherListWrapper.class);
return weatherWrapper.getforecastWeatherLists();
} catch (Exception e) {}
return null;
}
#Override
protected void onPostExecute(List<ForecastWeatherList> result) {
super.onPostExecute(result);
if (result != null) {
Log.e(TAG, "populate UI recycler view with gson converted data");
listener.afterSearch(result);
}
}
}
Here is the recyclerview adapter.
public class RecyclerViewAdapter extends
RecyclerView.Adapter<RecyclerViewAdapter.ForecastRecycler> {
List<ForecastWeatherList> mForecastWeatherDataList;
public static class ForecastRecycler extends RecyclerView.ViewHolder{
public TextView currentTemp;
public TextView currentHumidity;
public TextView currentDescription;
public ImageView currentIcon;
public ForecastRecycler (View view) {
super (view);
currentTemp = (TextView) view.findViewById(R.id.current_temperature);
currentHumidity = (TextView) view.findViewById(R.id.current_humidity);
currentDescription = (TextView) view.findViewById(R.id.current_weather_description);
currentIcon = (ImageView) view.findViewById(R.id.current_weather_icon);
}
}
public RecyclerViewAdapter(List<ForecastWeatherList> mForecastWeatherDataList, Context mContext) {
this.mForecastWeatherDataList = mForecastWeatherDataList;
}
#Override
public ForecastRecycler onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_item, parent, false);
final ForecastRecycler currentRecycler = new ForecastRecycler(view);
return currentRecycler;
}
#Override
public void onBindViewHolder( ForecastRecycler holder, int position) {
final ForecastWeatherList currentRecycler = mForecastWeatherDataList.get(position);
holder.currentTemp.setText((currentRecycler.getMain().getTempKf()));
holder.currentHumidity.setText(currentRecycler.getMain().getHumidity());
holder.currentDescription.setText(currentRecycler.getWeather().getDescription());
Picasso.with(holder.currentIcon.getContext()).load(currentRecycler.getWeather().getIcon());
}
#Override
public int getItemCount() {
return mForecastWeatherDataList.size();
}
}
Here are my current logs. I know its connecting to the server but I'm still getting no adapter attached error.
11371-11371/com.ksburneytwo.weathertest D/debugMode: The application is in onCreateView
11371-11396/com.ksburneytwo.weathertest D/debugMode: The application is in doInBackground
11371-11371/com.ksburneytwo.weathertest E/RecyclerView: No adapter attached; skipping layout
11371-11396/com.ksburneytwo.weathertest D/NetworkSecurityConfig: No Network Security Config specified, using platform default
11371-11396/com.ksburneytwo.weathertest D/debugMode: The application stopped after catch
Try notifyDataSetChanged() in adapter after initializing in onCreateView() method.
or use this approach:
Listener:
public interface Listener {
void afterSearch(List<ForecastWeatherList> result);
}
Fragment:
public class MyFragment extends Fragment implements Listener {
RecyclerView mRecyclerView;
List<ForecastWeatherList> items = new ArrayList<>();
RecyclerViewAdapter adapter;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_weather_app, container, false);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
mRecyclerView.addItemDecoration(new DividerItemDecoration(mRecyclerView.getContext(), DividerItemDecoration.VERTICAL));
adapter = new RecyclerViewAdapter(items, mRecyclerView.getContext());
mRecyclerView.setAdapter(adapter);
new GetWeatherAync(this, searchView, api_key).execute();
return view;
}
public afterSearch(List<ForecastWeatherList> result) {
items = result;
adapter.notifyDataSetChanged();
}
}
AsyncTask:
private static class GetWeatherAync extends AsyncTask<Context, Void, List<ForecastWeatherList>> {
private String TAG = GetWeatherAync.class.getSimpleName();
private final String serviceUrl;
private Context mContext;
private Listener listener;
public GetWeatherAync(Listener listener, Object searchView, Object api_key) {
this.listener = listener;
this.serviceUrl = "http://api.openweathermap.org/data/2.5/forecast?q=" + searchView + api_key;
}
#Override
protected List<ForecastWeatherList> doInBackground(Context...params) {
try {
URL url = new URL(serviceUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setDoOutput(true);
connection.setConnectTimeout(4000);
connection.setReadTimeout(4000);
connection.connect();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
ForecastWeatherListWrapper weatherWrapper = new Gson().fromJson(bufferedReader, ForecastWeatherListWrapper.class);
return weatherWrapper.getforecastWeatherLists();
} catch (Exception e) {}
return null;
}
#Override
protected void onPostExecute(List<ForecastWeatherList> result) {
super.onPostExecute(result);
if (result != null) {
Log.e(TAG, "populate UI recycler view with gson converted data");
listener.afterSearch(result);
}
}
}
I am developing an Android app that has the capability to sort movies by most popular or top rated from the moviedb.org api. The app is supposed to get new data from the server when the setting is changed. This is not working. Here is my code please help me through it:
//MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
if(savedInstanceState==null){
getSupportFragmentManager().beginTransaction().replace(R.id.fragment,new MainActivityFragment()).commit();
}
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
startActivity(new Intent(this,SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
}
//SettingsActivity.java
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref_general);
bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_order_key)));
}
public void bindPreferenceSummaryToValue(Preference preference){
preference.setOnPreferenceChangeListener(this);
onPreferenceChange(preference, PreferenceManager.getDefaultSharedPreferences(preference.getContext()).getString(preference.getKey(),""));
}
#Override
public boolean onPreferenceChange(Preference preference, Object value) {
String stringValue=value.toString();
if(preference instanceof ListPreference){
ListPreference listPreference=(ListPreference)preference;
int prefIndex=listPreference.findIndexOfValue(stringValue);
if(prefIndex>=0){
preference.setSummary(listPreference.getEntries()[prefIndex]);
}
}else {
preference.setSummary(stringValue);
}
return true;
}
//MainActivityFragment.java
public MainActivityFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView=inflater.inflate(R.layout.fragment_main, container, false);
if (getActivity()!=null){
ArrayList<String>arrayList=new ArrayList<String>();
PosterAdapter imageAdapter=new PosterAdapter(getActivity(),arrayList,deviceWidth);
imageGridView=(GridView)rootView.findViewById(R.id.image_grid_view);
imageGridView.setColumnWidth(deviceWidth);
imageGridView.setAdapter(imageAdapter);
}
imageGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent intent = new Intent(getActivity(), DetailActivity.class).putExtra("overview", overview.get(position))
.putExtra("poster", images.get(position))
.putExtra("title", title.get(position))
.putExtra("date", date.get(position))
.putExtra("rating", rating.get(position));
startActivity(intent);
}
});
return rootView;
}
private class PreferenceChangeListener implements SharedPreferences.OnSharedPreferenceChangeListener{
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
imageGridView.setAdapter(null);
onStart();
}
}
#Override
public void onStart(){
super.onStart();
sharedPreferences= PreferenceManager.getDefaultSharedPreferences(getActivity());
preferenceChangeListener=new PreferenceChangeListener();
sharedPreferences.registerOnSharedPreferenceChangeListener(preferenceChangeListener);
if (sharedPreferences.getString(getString(R.string.pref_order_key),"").equals(R.string.pref_order_most_popular)){
sortByPopular=true;
}else if (sharedPreferences.getString(getString(R.string.pref_order_key),"").equals(R.string.pref_order_top_rated)){
sortByPopular=false;
}
ImageLoader imageLoader=new ImageLoader();
if (isInternetAvailable()) {
imageLoader.execute();
Log.v(LOG_TAG,"async task completed");
}else {
TextView textView=new TextView(getActivity());
RelativeLayout relativeLayout=(RelativeLayout)getActivity().findViewById(R.id.fragment_layout);
textView.setText("There is no Internet service");
if (relativeLayout.getChildCount()==1){
relativeLayout.addView(textView);
}
imageGridView.setVisibility(GridView.GONE);
}
}
public boolean isInternetAvailable(){
ConnectivityManager connectivityManager=(ConnectivityManager)getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo=connectivityManager.getActiveNetworkInfo();
return networkInfo !=null&&networkInfo.isConnected();
}
public class ImageLoader extends AsyncTask<Void,Void,ArrayList<String>>{
#Override
protected ArrayList<String> doInBackground(Void... params) {
while (true){
try {
images=new ArrayList<>(Arrays.asList(getPathsFromURL(sortByPopular)));
return images;
}catch (Exception e){
continue;
}
}
}
#Override
protected void onPostExecute(ArrayList<String>results){
if (results!=null&&getActivity()!=null){
PosterAdapter posterAdapter=new PosterAdapter(getActivity(),results,deviceWidth);
imageGridView.setAdapter(posterAdapter);
}
}
public String[] getPathsFromURL(boolean sorting){
while (true){
HttpURLConnection httpURLConnection=null;
BufferedReader bufferedReader=null;
String JSONResult;
try {
if (sortByPopular){
url = "http://api.themoviedb.org/3/discover/movie?sort_by=popularity.desc&api_key=281ad0257e71bca17a21b42c9fee7304";
}else {
url="http://api.themoviedb.org/3/discover/movie?sort_by=vote_average.desc&vote_count.gte=500&api_key=281ad0257e71bca17a21b42c9fee7304";
}
URL url1=new URL(url);
httpURLConnection=(HttpURLConnection)url1.openConnection();
httpURLConnection.setRequestMethod("GET");
httpURLConnection.connect();
InputStream inputStream=httpURLConnection.getInputStream();
StringBuffer stringBuffer=new StringBuffer();
if (inputStream==null){
return null;
}
bufferedReader=new BufferedReader(new InputStreamReader(inputStream));
String data;
while ((data=bufferedReader.readLine())!=null){
stringBuffer.append(data+"\n");
}
if (stringBuffer.length()==0){
return null;
}
JSONResult=stringBuffer.toString();
Log.v(LOG_TAG,JSONResult);
try {
overview=new ArrayList<String>(Arrays.asList(getStringsFromAPI(JSONResult, "overview")));
title=new ArrayList<String>(Arrays.asList(getStringsFromAPI(JSONResult, "original_title")));
rating=new ArrayList<String>(Arrays.asList(getStringsFromAPI(JSONResult, "vote_average")));
date=new ArrayList<String>(Arrays.asList(getStringsFromAPI(JSONResult, "release_date")));
return getDataFromJSON(JSONResult);
}catch (JSONException e){
return null;
}
}catch (Exception e){
continue;
}finally {
if (httpURLConnection!=null){
httpURLConnection.disconnect();
}
if (bufferedReader!=null){
try {
bufferedReader.close();
}catch (final IOException e){
}
}
}
}
}
}
public String[] getStringsFromAPI(String JSONStringParameter,String parameter) throws JSONException{
JSONObject jsonObject=new JSONObject(JSONStringParameter);
JSONArray jsonArray=jsonObject.getJSONArray("results");
String[] results=new String[jsonArray.length()];
for (int i=0;i<jsonArray.length();i++){
JSONObject poster=jsonArray.getJSONObject(i);
if (parameter.equals("vote_average")){
Double decimalNumber=poster.getDouble("vote_average");
String userRating=Double.toString(decimalNumber)+"/10";
results[i]=userRating;
}
String posterPath=poster.getString(parameter);
results[i]=posterPath;
}
return results;
}
public String[] getDataFromJSON(String JSONStringParameter)throws JSONException{
JSONObject jsonObject=new JSONObject(JSONStringParameter);
JSONArray jsonArray=jsonObject.getJSONArray("results");
String[] results=new String[jsonArray.length()];
for (int i=0;i<jsonArray.length();i++){
JSONObject poster=jsonArray.getJSONObject(i);
String posterPath=poster.getString("poster_path");
results[i]=posterPath;
}
return results;
}
//PosterAdapter.java
private Context context;
private ArrayList<String> arrayList;
private int posterWidth;
public PosterAdapter(Context c,ArrayList<String> filePaths,int a){
context=c;
arrayList=filePaths;
posterWidth=a;
}
#Override
public int getCount() {
return arrayList.size();
}
#Override
public Object getItem(int position) {
return null;
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView image;
if (convertView==null){
image=new ImageView(context);
}else {
image=(ImageView)convertView;
}
String url = "http://image.tmdb.org/t/p/w185" + arrayList.get(position);
Picasso.with(context).load(url).into(image);
return image;
}
Thank you in advance
I spoke to another developer and it appears that my code is accurate and there is a bug that the other developer is trying to figure out. I'll keep you guys posted. Thank you for your help.
In my project a read data from a CMS I created through a JSON response. My problem is when I click the refresh button the data are read twice!. Here is my fragment's code.
public class FootballNews extends Fragment {
public static final String TAG = "ManuApp";
private static final String IMAGE_URL = "http://xxx//manucms/football_news_images/" ;
private List<FootballNewsObject> listItemsList;
private RecyclerView mRecyclerView;
private FootballNewsAdapter adapter;
public FootballNews() {
// Required empty public constructor
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
setRetainInstance(true);
View v = inflater.inflate(R.layout.fragment_football_news, container, false);
// Inflate the layout for this fragment
listItemsList = new ArrayList<FootballNewsObject>();
mRecyclerView = (RecyclerView)v.findViewById(R.id.recycler_view);
//mRecyclerView.addItemDecoration(new HorizontalDividerItemDecoration.Builder(getActivity()).color(Color.BLACK).build());
final LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(linearLayoutManager);
return v;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
updateList();
}
public void updateList() {
//declare the adapter and attach it to the recyclerview
adapter = new FootballNewsAdapter(getActivity(), listItemsList);
mRecyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(getActivity());
// Clear the adapter because new data is being added from a new subreddit
//adapter.clearAdapter();
//showPD();
// Request a string response from the provided URL.
JsonArrayRequest jsObjRequest = new JsonArrayRequest(Request.Method.GET, Config.URL_FOOTBALL_NEWS, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
//hidePD();
// Parse json data.
// Declare the json objects that we need and then for loop through the children array.
// Do the json parse in a try catch block to catch the exceptions
try {
for (int i = 0; i < response.length(); i++) {
JSONObject post = response.getJSONObject(i);
FootballNewsObject item = new FootballNewsObject();
item.setTitle(post.getString("title"));
item.setImage(IMAGE_URL + post.getString("news_image"));
item.setArticle(post.getString("article"));
listItemsList.add(item);
}
} catch (JSONException e) {
e.printStackTrace();
}
// Update list by notifying the adapter of changes
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
//hidePD();
}
});
jsObjRequest.setRetryPolicy(new RetryPolicy() {
#Override
public int getCurrentTimeout() {
return 50000;
}
#Override
public int getCurrentRetryCount() {
return 50000;
}
#Override
public void retry(VolleyError error) throws VolleyError {
}
});
queue.add(jsObjRequest);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
getActivity().getMenuInflater().inflate(R.menu.main, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if(id == R.id.refresh){
if(isOnline()) {
updateList();
}else{
Toast.makeText(getActivity(),"There is no internet connection",Toast.LENGTH_SHORT).show();
}
}
return super.onOptionsItemSelected(item);
}
protected boolean isOnline() {
ConnectivityManager cm = (ConnectivityManager)getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
return true;
} else {
return false;
}
}
}
Basically I am running the updateList method twice. Once in the onActivityCreated(...) method,and secondly inside the onOptionsItemSelected(...).
Finally here is my adapter.
public class FootballNewsAdapter extends RecyclerView.Adapter<FootballNewsRowHolder>{
private List<FootballNewsObject> footballNewsObjectList;
private Context mContext;
private ImageLoader mImageLoader;
private int focused = 0;
public FootballNewsAdapter(Activity activity, List<FootballNewsObject> footballNewsObjectList){
this.footballNewsObjectList = footballNewsObjectList;
this.mContext = activity;
}
#Override
public FootballNewsRowHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.football_news_row,null);
final FootballNewsRowHolder holder = new FootballNewsRowHolder(v);
return holder;
}
#Override
public void onBindViewHolder(FootballNewsRowHolder holder, int position) {
final FootballNewsObject listItems = footballNewsObjectList.get(position);
holder.itemView.setSelected(focused==position);
holder.getLayoutPosition();
mImageLoader = AppController.getInstance().getImageLoader();
holder.thumbnail.setImageUrl(listItems.getImage(),mImageLoader);
holder.thumbnail.setDefaultImageResId(R.drawable.reddit_placeholder);
holder.name.setText(Html.fromHtml(listItems.getTitle()));
holder.relativeLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String title = listItems.getTitle();
String article = listItems.getArticle();
String image = listItems.getImage();
Intent i = new Intent(mContext, Extras.class);
i.putExtra("title",title);
i.putExtra("article",article);
i.putExtra("image",image);
mContext.startActivity(i);
//Toast.makeText(mContext,"You clicked",Toast.LENGTH_SHORT).show();
//Intent intent = new Intent(mContext,WebActivity.class);
//intent.putExtra("url",postUrl);
// mContext.startActivity(intent);
}
});
}
#Override
public int getItemCount() {
return (null != footballNewsObjectList?footballNewsObjectList.size() :0 );
}
}
Any ideas?
Thanks
You are adding to your list in your refresh method, instead of updating. Add
listItemsList.clear();
at the beginning of your refresh function (updateList).
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
I am getting this error-Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference
This is what i have done!
PeopleListFragment
**PeopleListFragment**
public class PeopleListFragment extends Fragment{
public static final String DISPLAY_URL = ServiceAPI.URL_CONTACTS;
private static final String TAG = "PeopleListActivity";
public static final boolean DEBUG = Constant.DEBUG;
private ProgressDialog progressDialog;
public PeopleAdapter adapter;
private GetAllPeopleTask mGetAllPeople = null;
private Intent intent;
public static ListView mContactlistView;
public PeopleListFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_people_list, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mContactlistView = (ListView) view.findViewById(R.id.people_list);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
List<People> contactList = new ArrayList<People>();
adapter = new PeopleAdapter(getActivity().getApplicationContext(),
R.layout.people_list_item, contactList);
mContactlistView.setAdapter(adapter);
mContactlistView.setTextFilterEnabled(true);
mContactlistView.setFastScrollEnabled(true);
mContactlistView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String empId = String.valueOf(adapter.getItem(position).getEmployeeId());
String name = String.valueOf(adapter.getItem(position).getFirstName());
intent = new Intent(getActivity(),
PeopleDetailsActivity.class);
intent.putExtra("EmployeeId", empId);
intent.putExtra("name", name);
startActivity(intent);
}
});
startAsyncTask();
TextView textView = new TextView(getContext());
textView.setText("Empty");
mContactlistView.setEmptyView(textView);
}
public void startAsyncTask() {
mGetAllPeople = new GetAllPeopleTask();
mGetAllPeople.execute(DISPLAY_URL, "12345678");
}
public class GetAllPeopleTask extends AsyncTask<String, Void, List<People>> {
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = new ProgressDialog(getActivity());
progressDialog.setMessage("Loading");
progressDialog.show();
}
#Override
protected ArrayList<People> doInBackground(String... params) {
ArrayList<People> peopleList = new ArrayList<>();
try {
URL url = new URL(params[0]);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setReadTimeout(40000);
httpURLConnection.setConnectTimeout(50000);
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setRequestProperty("Content-Type", "application/json");
httpURLConnection.setRequestProperty("Accept", "application/json");
httpURLConnection.setDoOutput(true);
JSONObject request = new JSONObject();
request.put("session", params[1]);
String bodyParams = request.toString();
if (DEBUG) {
Log.i(TAG, bodyParams);
}
httpURLConnection.setRequestProperty("Content-Length",
String.valueOf(bodyParams.getBytes().length));
DataOutputStream outputStream = new DataOutputStream(httpURLConnection.getOutputStream());
outputStream.writeBytes(bodyParams);
outputStream.flush();
outputStream.close();
httpURLConnection.connect();
if (httpURLConnection.getResponseCode() == 200) {
Log.i(TAG, "Success");
} else {
Log.i(TAG, "Error Code :" + httpURLConnection.getResponseCode());
}
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
StringBuilder builder = new StringBuilder();
while ((line = reader.readLine()) != null) {
builder.append(line);
}
Log.i(TAG, "Builder String : " + builder.toString());
JSONObject jsonObject = new JSONObject(builder.toString());
Log.i(TAG, "Response JSON : " + jsonObject.toString());
if (jsonObject.has("responseData")) {
JSONArray responseDataArr = jsonObject.optJSONArray("responseData");
for (int i = 0; i < responseDataArr.length(); i++) {
JSONObject peopleJSON = responseDataArr.optJSONObject(i);
People people = new People();
people.setEmployeeId(peopleJSON.optString("employeeId"));
people.setFirstName(peopleJSON.optString("firstName"));
people.setLastName(peopleJSON.optString("lastName"));
// Log.i("hebsiba ", "People first name" + people.getFirstName() + ", last name is " + people.getLastName()) ;
if((!people.getFirstName().isEmpty()) && (!people.getLastName().isEmpty())) {
peopleList.add(people);
}
if (DEBUG) {
Log.i(TAG, "People " + people.getEmployeeId());
}
}
}
} catch (IOException | JSONException e) {
Log.e(TAG, e.toString());
}
return peopleList;
}
#Override
protected void onPostExecute(List<People> people) {
super.onPostExecute(people);
Collections.sort(people, new Comparator<People>() {
#Override
public int compare(People lhs, People rhs) {
return lhs.getFirstName().compareToIgnoreCase(rhs.getFirstName());
}
});
adapter.addAll(people);
if (DEBUG) {
Log.i(TAG, adapter.getCount() + " ");
}
Log.v(TAG, String.valueOf(people.size()));
progressDialog.dismiss();
}
}
}
This is the PeopleAdapter
**PeopleAdapter**
public class PeopleAdapter extends ArrayAdapter<People> implements Filterable {
private PeopleListActivity activity;
private PeopleFilter peopleFilter;
private List<People> peopleList;
private List<People> filteredList;
public PeopleAdapter(Context applicationContext, int people_list_item, List<People> contactList) {
super(applicationContext, people_list_item, contactList);
filteredList = contactList;
getFilter();
}
#Override
public int getCount() {
return filteredList.size();
}
#Override
public People getItem(int i) {
return filteredList.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
People peopleList = getItem(position);
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.people_list_item, null);
holder = new ViewHolder();
holder.firstName = (TextView) convertView.findViewById(R.id.firstName);
holder.lastName = (TextView) convertView.findViewById(R.id.lastName);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.firstName.setText(peopleList.getFirstName());
holder.lastName.setText(peopleList.getLastName());
return convertView;
}
/**
* Get custom filter
* #return filter
*/
#Override
public Filter getFilter() {
if (peopleFilter == null) {
peopleFilter = new PeopleFilter();
}
return peopleFilter;
}
static class ViewHolder {
TextView firstName;
TextView lastName;
}
private class PeopleFilter extends Filter {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults filterResults = new FilterResults();
if (constraint!=null && constraint.length()>0) {
ArrayList<People> tempList = new ArrayList<>();
// search content in friend list
for (People user : peopleList) {
if (user.getFirstName().toLowerCase().contains(constraint.toString().toLowerCase())) {
tempList.add(user);
}
}
filterResults.count = tempList.size();
filterResults.values = tempList;
} else {
filterResults.count = peopleList.size();
filterResults.values = peopleList;
}
return filterResults;
}
/**
* Notify about filtered list to ui
* #param constraint text
* #param results filtered result
*/
#SuppressWarnings("unchecked")
#Override
protected void publishResults(CharSequence constraint, Filter.FilterResults results) {
filteredList = (ArrayList<People>) results.values;
notifyDataSetChanged();
}
}
}
And this is PeopleListActivity
**PeopleListActivity**
public class PeopleListActivity extends AppCompatActivity implements SearchView.OnQueryTextListener {
private PeopleListFragment fragment;
private FragmentManager displayFragment;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
Window window = getWindow();
window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
window.setStatusBarColor(Color.argb(255, 180, 110, 60));
}
setContentView(R.layout.activity_people);
Toolbar toolbar = (Toolbar) findViewById(R.id.people_toolbar);
setSupportActionBar(toolbar);
toolbar.setNavigationIcon(R.drawable.ic_back_arrow);
getSupportActionBar().setDisplayShowTitleEnabled(false);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(PeopleListActivity.this, NavigationActivity.class);
startActivity(intent);
}
});
displayFragment = getSupportFragmentManager();
fragment = new PeopleListFragment();
displayFragment.beginTransaction().add(R.id.people_fragment, fragment).commit();
if (savedInstanceState == null) {
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.options_menu, menu);
SearchManager searchManager =(SearchManager) getSystemService(Context.SEARCH_SERVICE);
SearchView searchView =(SearchView) menu.findItem(R.id.search).getActionView();
searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
// searchView.setIconifiedByDefault(false);
searchView.setSubmitButtonEnabled(true);
searchView.setOnQueryTextListener(this);
return true;
// return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onQueryTextSubmit(String query) {
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
PeopleAdapter peopleAdapter = (PeopleAdapter) PeopleListFragment.mContactlistView.getAdapter();
peopleAdapter.getFilter().filter(newText);
return true;
}
}
Could anyone help me with this..?
Assign some value to filteredList when you create the Adapter
Example:
public PeopleAdapter(Context applicationContext, int people_list_item, List<People> contactList) {
super(applicationContext, people_list_item, contactList);
filteredList = contactList;
getFilter();
}
filteredList is null when getCount() is called. Instantiate it first or make sure filteredList has some content.
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 7 years ago.
I am using a RecyclerView and a Async Task to update the view in this RecyclerView but I am getting a null pointer exception at a RecyclerView.setAdapter. My FetchMoviePoster class contains the Async Task and PhotoAlbumAdapter contains the adapter for the Recycler View.
Can anyone please help me with that
MainActivityFragment
public class MainActivityFragment extends Fragment implements PhotoAlbumAdapter.OnItemClickListener {
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
PhotoAlbumAdapter mAdapter;
FetchMoviePoster movie_fetch;
public MainActivityFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.movie_sort, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_sort) {
return true;
}
if(id== R.id.pop){
updateMovie("popularity.desc");
return true;
}
if(id== R.id.vote){
updateMovie("vote_average.desc");
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.recyle_view);
recyclerView.setHasFixedSize(true);
layoutManager = new GridLayoutManager(getActivity(), 2, GridLayoutManager.VERTICAL, false);
recyclerView.setLayoutManager(layoutManager);
movie_fetch= new FetchMoviePoster();
registerForContextMenu(recyclerView);
updateMovie("vote_count.desc");
return rootView;
}
private void updateMovie(String c) {
movie_fetch.execute(c);
}
#Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
getActivity().getMenuInflater().inflate(R.menu.pop_up_menu, menu);
}
public void update_the_Adaptor(String[] st){
mAdapter = new PhotoAlbumAdapter(new ArrayList<>(Arrays.asList(st)), getContext());
recyclerView.setAdapter(mAdapter);
mAdapter.SetOnItemClickListener(MainActivityFragment.this);
}
#Override
public void onItemClick(View view, int position) {
Log.v("Actual position", Integer.toString(position));
Intent detail= new Intent(getActivity(),DetailActivity.class);
detail.putExtra("position",position);
detail.putExtra("poster", movie_fetch.resultStrs);
detail.putExtra("title",movie_fetch. movie_title);
detail.putExtra("plot", movie_fetch.movie_plot);
detail.putExtra("user_rating", movie_fetch.user_rating);
detail.putExtra("release", movie_fetch.release_date);
startActivity(detail);
}
}
My PhotoAlbumAdapterClass
public class PhotoAlbumAdapter extends RecyclerView.Adapter<PhotoAlbumAdapter.ViewHolder> {
ArrayList<String> image;
Context context;
OnItemClickListener mClickListener;
public PhotoAlbumAdapter(ArrayList<String> imageView, Context context) {
image=imageView;
this.context=context;
}
#Override
public PhotoAlbumAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v= LayoutInflater.from(parent.getContext()).inflate(R.layout.image_holder,parent,false);
ViewHolder vh=new ViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(final PhotoAlbumAdapter.ViewHolder holder, int position) {
String st=image.get(position);
Uri uri=Uri.parse(st);
Picasso.with(context).load(uri)
.into(holder.img);
AnimationsUtils.animate(holder);
}
#Override
public int getItemCount() {
return image.size();
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
ImageView img;
public ViewHolder(View itemView) {
super(itemView);
img = (ImageView) itemView.findViewById(R.id.imageView);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View view) {
if(mClickListener !=null)
mClickListener.onItemClick(view, getAdapterPosition()); //OnItemClickListener mItemClickListener;
}
}
public interface OnItemClickListener {
void onItemClick(View view, int position);
}
public void SetOnItemClickListener(final OnItemClickListener m){
mClickListener=m;
}
}
My FetchMoviePoster class
public class FetchMoviePoster extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchMoviePoster.class.getSimpleName();
String choice;
String[] resultStrs;
String[] movie_title;
String[] movie_plot;
String[] user_rating;
String[] release_date;
#Override
protected String[] doInBackground(String... code) {
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String[] image_poster = new String[0];
String API = "api_key";
String SORT="sort_by";
choice=code[0];
String forecastJsonStr = null;
try {
Uri fetch_url = Uri.parse("http://api.themoviedb.org/3/discover/movie?");
Uri builder = fetch_url.buildUpon().
appendQueryParameter(SORT,choice)
.appendQueryParameter(API, BuildConfig.THE_MOVIE_DB_API_KEY).build();
URL url = new URL(builder.toString());
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
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) {
buffer.append(line + "/n");
}
if (buffer.length() == 0) {
return null;
}
forecastJsonStr = buffer.toString();
try {
image_poster = getUrlForImage(forecastJsonStr);
} catch (JSONException e) {
e.printStackTrace();
}
} catch (IOException e) {
Log.e(LOG_TAG, "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(LOG_TAG, "Error closing stream", e);
}
}
}
return image_poster;
}
private String[] getUrlForImage(String forecastJsonStr) throws JSONException {
final String OWM_POSTER = "results";
final String FILE_PATH = "poster_path";
final String ORIGINAL_TITLE="original_title";
final String OVERVIEW="overview";
final String User_RATING="vote_average";
final String RELEASE="release_date";
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray movieArray = forecastJson.getJSONArray(OWM_POSTER);
resultStrs = new String[movieArray.length()];
movie_title=new String[movieArray.length()];
movie_plot=new String[movieArray.length()];
user_rating=new String[movieArray.length()];
release_date=new String[movieArray.length()];
for (int i = 0; i < movieArray.length(); i++) {
JSONObject movie = movieArray.getJSONObject(i);
String file_name = movie.getString(FILE_PATH);
String title=movie.getString(ORIGINAL_TITLE);
String plot=movie.getString(OVERVIEW);
String userRating=movie.getString(User_RATING);
String release=movie.getString(RELEASE);
resultStrs[i] = "http://image.tmdb.org/t/p/w185/" +file_name;
movie_title[i]=title;
movie_plot[i]=plot;
user_rating[i]= userRating;
release_date[i]=release;
}
return resultStrs;
}
#Override
protected void onPostExecute(String[] resultStrs) {
if (resultStrs != null) {
new MainActivityFragment().update_the_Adaptor(resultStrs);
}
}
}
LogCat
12-12 20:24:22.066 4229-4229/com.example.dell.movielove W/dalvikvm:
threadid=1: thread exiting with uncaught exception (group=0x41915c08)
12-12 20:24:22.136 4229-4229/com.example.dell.movielove E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.dell.movielove, PID: 4229
java.lang.NullPointerException
at
com.example.dell.movielove.MainActivityFragment.update_the_Adaptor(MainActivityFragment.java:99)
at
com.example.dell.movielove.FetchMoviePoster.onPostExecute(FetchMoviePoster.java:138)
at
com.example.dell.movielove.FetchMoviePoster.onPostExecute(FetchMoviePoster.java:19)
at android.os.AsyncTask.finish(AsyncTask.java:632)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at
android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5641)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1288)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1104)
at dalvik.system.NativeStart.main(Native Method)
Check onPostExecute method of Async task:
#Override
protected void onPostExecute(String[] resultStrs) {
if (resultStrs != null) {
//creating new instance not using old
new MainActivityFragment().update_the_Adaptor(resultStrs);
}
}
on new instance of MainActivityFragment you are calling update_the_Adaptor()
public void update_the_Adaptor(String[] st){
// st is not null
mAdapter = new PhotoAlbumAdapter(new ArrayList<>(Arrays.asList(st)), getContext());
recyclerView.setAdapter(mAdapter);//null recycler view as onCreate is not called
mAdapter.SetOnItemClickListener(MainActivityFragment.this);
}
You call
new MainActivityFragment().update_the_Adaptor(resultStrs);
But you MainActivityFragment didn't create because you didn't use FragmentManager to commit your fragment so onCreateView will not be called and recyclerView is null, your NullPointerException will be thrown from update_the_Adaptor.