This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
I am making an app that has four tabs in the tabs I am using a json request to get the data of events from a url.When I run the code its displays a null pointer exception error.
Here is my code
package com.alex.jay.turnapp;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
import static com.alex.jay.turnapp.AppController.*;
public class EventsActivity extends Fragment {
String url = "http://192.168.43.114/Turnapp/retrieveevents.php";
ProgressDialog dialog;
private List<EventItem> array_events = new ArrayList<>();
EventsAdapter adapter;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final View V = inflater.inflate(R.layout.events_tab, container, false);
RecyclerView recycler = (RecyclerView) V.findViewById(R.id.rv);
adapter = new EventsAdapter(getActivity(), array_events);
LinearLayoutManager mLayoutManager = new LinearLayoutManager(getActivity());
recycler.setLayoutManager(mLayoutManager);
recycler.setItemAnimator(new DefaultItemAnimator());
recycler.setAdapter(adapter);
dialog = new ProgressDialog(getActivity());
dialog.setMessage("Loading events...");
dialog.show();
if (array_events != null) {
array_events.clear();
}
StringRequest request = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
#Override
public void onResponse(String s) {
try {
hideDialog();
Log.d("Sever Message", s);
JSONObject events = new JSONObject(s);
JSONArray jsonArray = events.getJSONArray("events");
JSONObject jobject = null;
int len = jsonArray.length();
for (int i = 0; i < len; i++) {
jobject = jsonArray.getJSONObject(i);
EventItem eventsdata = new EventItem();
eventsdata.setEventname(jobject.getString("1"));
eventsdata.setVenue(jobject.getString("2"));
eventsdata.setImages(jobject.getString("3"));
eventsdata.setEventdate(jobject.getString("4"));
array_events.add(eventsdata);
}
adapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError volleyError) {
}
});
AppController.getInstance().addToRequestQueue(request);
recycler.addOnItemTouchListener(new RecyclerTouchListener(getActivity(), recycler, new ClickListener() {
#Override
public void onClick(View view, int position) {
Intent intent = new Intent(getActivity(), Events.class);
intent.putExtra("eventname", array_events.get(position).getEventname());
intent.putExtra("eventlocation", array_events.get(position).getvenue());
intent.putExtra("eventimage", array_events.get(position).getImages());
startActivity(intent);
}
#Override
public void onLongClick(View view, int position) {
}
}));
return V;
}
public void hideDialog() {
if (dialog != null) {
dialog.dismiss();
dialog = null;
}
}
public interface ClickListener {
void onClick(View view, int position);
void onLongClick(View view, int position);
}
public static class RecyclerTouchListener implements RecyclerView.OnItemTouchListener {
GestureDetector gestureDetector;
EventsActivity.ClickListener clickListener;
public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final EventsActivity.ClickListener clickListener) {
this.clickListener = clickListener;
gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
#Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
#Override
public void onLongPress(MotionEvent e) {
View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null) {
clickListener.onLongClick(child, recyclerView.getChildPosition(child));
}
}
});
}
#Override
public boolean onInterceptTouchEvent(RecyclerView recycler, MotionEvent e) {
View child = recycler.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
clickListener.onClick(child, recycler.getChildPosition(child));
}
return false;
}
#Override
public void onTouchEvent(RecyclerView recycler, MotionEvent e) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
}
Here is the AppController code
public class AppController extends Application {
public static final String TAG = AppController.class.getSimpleName();
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
private static AppController mInstance;
#Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
public static synchronized AppController getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public ImageLoader getImageLoader() {
getRequestQueue();
if (mImageLoader == null) {
mImageLoader = new ImageLoader(this.mRequestQueue,
new BitmapCache());
}
return this.mImageLoader;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
// set the default tag if tag is empty
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public <T> void addToRequestQueue(Request<T> req) {
req.setTag(TAG);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
}
Here is the error
05-05 13:43:21.083 17540-17540/com.alex.jay.turnapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.alex.jay.turnapp, PID: 17540
java.lang.NullPointerException: Attempt to invoke virtual method 'void com.alex.jay.turnapp.AppController.addToRequestQueue(com.android.volley.Request)' on a null object reference
at com.alex.jay.turnapp.EventsActivity.onCreateView(EventsActivity.java:100)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1974)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:742)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentTabHost.onAttachedToWindow(FragmentTabHost.java:283)
at android.view.View.dispatchAttachedToWindow(View.java:13716)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2815)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2822)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1560)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1301)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6607)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:800)
at android.view.Choreographer.doCallbacks(Choreographer.java:603)
at android.view.Choreographer.doFrame(Choreographer.java:572)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:786)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5631)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754)
Please help
Seems like the method AppController.getInstance() returns NULL. Please find an example of how to implement the Singleton below.
https://gist.github.com/Akayh/5566992
Related
I am trying to display json array which is inside a json object but nothing is displaying on the text view. I debugged and found that info.java class is working fine. If i am passing the simple string value(after removing the json parsing java code) in the info.java class it's working but i am unable to pass json data.
Singleton.java
package com.example.osama.recyclerthug;
import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;
public class Singleton {
private static Singleton mInstance;
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
private static Context mCtx;
private Singleton(Context context){
mCtx = context;
mRequestQueue =getRequestQueue();
mImageLoader = new ImageLoader(mRequestQueue,
new ImageLoader.ImageCache() {
private final LruCache<String, Bitmap>
cache = new LruCache<String, Bitmap>(20);
#Override
public Bitmap getBitmap(String url) {
return cache.get(url);
}
#Override
public void putBitmap(String url, Bitmap bitmap) {
cache.put(url, bitmap);
}
});
}
public static synchronized Singleton getInstance(Context context){
if (mInstance == null){
mInstance = new Singleton(context);
}
return mInstance;
}
public RequestQueue getRequestQueue(){
if (mRequestQueue == null){
mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> request){
getRequestQueue().add(request);
}
public ImageLoader getmImageLoader(){
return mImageLoader;
}
}
...................................................................
ThugAdapter.java
package com.example.osama.recyclerthug;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
public class ThugAdapter extends RecyclerView.Adapter<ThugAdapter.ThugHolder> {
ArrayList<Info> arrayList1;
public ThugAdapter(ArrayList<Info> arrayList){
this.arrayList1 = arrayList;
}
#NonNull
#Override
public ThugHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext());
View view = inflater.inflate(R.layout.appearance, viewGroup, false);
ThugHolder thugHolder = new ThugHolder(view);
return thugHolder;
}
#Override
public void onBindViewHolder(#NonNull ThugHolder thugHolder, int i) {
thugHolder.text.setText(arrayList1.get(i).getTxt1());
thugHolder.text2.setText(arrayList1.get(i).getTxt2());
/* thugHolder.image.setImageURI(arrayList.get(i).getImageUri());*/
}
#Override
public int getItemCount() {
return arrayList1.size();
}
public class ThugHolder extends RecyclerView.ViewHolder{
TextView text,text2;
ImageView image;
public ThugHolder(#NonNull View itemView) {
super(itemView);
text = itemView.findViewById(R.id.textView);
text2 = itemView.findViewById(R.id.textView2);
image = itemView.findViewById(R.id.imageView);
}
}
}
............................................................................
Info.java
package com.example.osama.recyclerthug;
import android.net.Uri;
public class Info {
private String txt1,txt2;
// private Uri imageuri;
public Info(String txt1, String txt2/*, Uri imageuri*/){
this.setTxt1(txt1);
this.setTxt2(txt2);
/* this.setImageUri(imageuri);*/
}
public String getTxt1() {
return txt1;
}
public void setTxt1(String txt1) {
this.txt1 = txt1;
}
public String getTxt2() {
return txt2;
}
public void setTxt2(String txt2) {
this.txt2 = txt2;
}
/*public Uri getImageUri() {
return imageuri;
}
public void setImageUri(Uri imageuri) {
this.imageuri = imageuri;
}*/
}
........................................................
BackgroundTask.java
package com.example.osama.recyclerthug;
import android.content.Context;
import android.net.Uri;
import android.util.Log;
import android.widget.Toast;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.JsonObjectRequest;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class BackgroundTask {
Context context;
ArrayList<Info> arrayList;
String json_url = "http://cc97cf60.ngrok.io/api/note/";
public BackgroundTask(Context context){
this.context = context;
}
public ArrayList<Info> getArrayList(){
arrayList = new ArrayList<>();
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, json_url, null,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
JSONArray jsonArray ;
try {
jsonArray = response.getJSONArray("objects");
int i;
for (i = 0; i < jsonArray.length(); i++){
JSONObject jsonObject = (JSONObject) jsonArray.get(i);
/* Uri b = Uri.parse(jsonObject.getString("image")); //Type casting string to uri*/
String a = jsonObject.getString("title");
String b = jsonObject.getString("body");
Info info = new Info(a,b);
arrayList.add(info);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
});
Singleton.getInstance(context).addToRequestQueue(jsonObjectRequest);
return arrayList;
}
}
..............................................
MainActivity.java
package com.example.osama.recyclerthug;
import android.app.DownloadManager;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import org.json.JSONObject;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
RecyclerView recyclerView;
RecyclerView.LayoutManager layoutManager;
ThugAdapter thugAdapter;
BackgroundTask backgroundTask;
ArrayList<Info> arrayList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recycler);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
backgroundTask = new BackgroundTask(this);
arrayList = new ArrayList<>();
arrayList= backgroundTask.getArrayList();
thugAdapter = new ThugAdapter(arrayList);
recyclerView.setAdapter(thugAdapter);
}
}
Edit: Below is the json data:
{
"meta": {
"limit": 20,
"next": null,
"offset": 0,
"previous": null,
"total_count": 2
},
"objects": [
{
"body": "Breaking News:\r\nOsama Abrar is Iron Man.",
"created_at": "2018-12-08T08:40:59.949776",
"id": 1,
"image": "https://wonderfulengineering.com/wp-content/uploads/2016/01/iron-man-wallpaper-6.jpg",
"resource_uri": "/api/note/1/",
"title": "Iron Man"
},
{
"body": "Will Iron Man aka Osama Abrar survive?",
"created_at": "2018-12-08T08:41:40.279677",
"id": 2,
"image": "https://marciokenobi.files.wordpress.com/2013/03/iron_man.jpg",
"resource_uri": "/api/note/2/",
"title": "End Game"
}
]
}
JSON parsing is OK but you can't retrieve your data like this because you used Volley in asynchronous mode. It means that you can't assume that data will be retrieved as soon as you put the request in the queue. Maybe the queue is very long and your request can be sent later. So, when you tried to retrieve your data, you've seen that your arrayList is null, and it's normal. To deal with the asynchronous way, you have to tell Volley : "tell me when you've retrieved data". And you can do this with a listener.
Here is an example.
public interface Listener {
void onDataReceived(ArrayList<Info> list);
void onError(int error);
}
BackgroundTask
public class BackgroundTask {
Context context;
ArrayList<Info> arrayList;
Listener mListener; // listener to retrieve data
String json_url = "http://cc97cf60.ngrok.io/api/note/";
public BackgroundTask(Context context, Listener listener) {
this.context = context;
mListener = listener;
}
public void getArrayList() { // no return needed
arrayList = new ArrayList<>();
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, json_url, null,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
JSONArray jsonArray;
try {
jsonArray = response.getJSONArray("objects");
int i;
for (i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = (JSONObject) jsonArray.get(i);
/* Uri b = Uri.parse(jsonObject.getString("image")); //Type casting string to uri*/
String a = jsonObject.getString("title");
String b = jsonObject.getString("body");
Info info = new Info(a, b);
arrayList.add(info);
}
} catch (JSONException e) {
e.printStackTrace();
}
// if listener has been set, send data
if (mListener != null) {
mListener.onDataReceived(arrayList);
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
// if listener has been set, send error
if (mListener != null) {
mListener.onError(error.networkResponse.statusCode);
}
}
});
Singleton.getInstance(context).addToRequestQueue(jsonObjectRequest);
}
}
In your MainActivity :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recycler);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
backgroundTask = new BackgroundTask(this, new Listener() {
#Override
public void onDataReceived(ArrayList<Info> list) {
thugAdapter = new ThugAdapter(list);
recyclerView.setAdapter(thugAdapter);
}
#Override
public void onError(int error) {
}
});
backgroundTask.getArrayList();
}
And that is !
Currently, I'm developing a media player, and I want hide a element when audio finishes. But when it happens, the app crash with this error: Attempt to invoke virtual method 'void android.widget.LinearLayout.setVisibility(int)' on a null object reference. Check my current code:
meplayer.java
package etes.xddda.music;
import android.app.Activity;
import android.content.Context;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Toast;
public class meplayer extends Activity {
public static MediaPlayer mediaPlayer;
public LinearLayout menu_dialog;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
menu_dialog = findViewById(R.id.menu_dialog);
}
public void initAudio(final Context context, final String url) {
if (mediaPlayer == null) {
mediaPlayer = MediaPlayer.create(context, Uri.parse(url));
}
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
public LinearLayout menu_dialog;
#Override
public void onCompletion(MediaPlayer mp) {
//Toast.makeText(context, "TEST", Toast.LENGTH_LONG).show();
killMediaPlayer();
menu_dialog.setVisibility(View.GONE);
}
});
mediaPlayer.start();
}
private void killMediaPlayer() {
if (mediaPlayer != null) {
try {
mediaPlayer.reset();
mediaPlayer.release();
mediaPlayer = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
RecyclerViewAdapter
package etes.xddda.music;
import android.app.Dialog;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.media.MediaPlayer;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.List;
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> implements View.OnClickListener{
Context mContext;
List<mList> mData;
Dialog myDialog;
private MediaPlayer mediaPlayer;
private int playbackPosition=0;
meplayer media;
private LinearLayout menu_dialog;
public RecyclerViewAdapter(Context mContext, List<mList> mData) {
this.mContext = mContext;
this.mData = mData;
}
public void onClick(View view) {
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v;
v = LayoutInflater.from(mContext).inflate(R.layout.item_list, parent, false);
final MyViewHolder vHolder = new MyViewHolder(v);
// Dialog ini
myDialog = new Dialog(mContext);
myDialog.setContentView(R.layout.dialog);
myDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
vHolder.item_play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
TextView dialog_name_tv = (TextView) myDialog.findViewById(R.id.dialog_name_id);
TextView dialog_phone_tv = (TextView) myDialog.findViewById(R.id.dialog_author_id);
ImageView dialog_contact_img = (ImageView) myDialog.findViewById(R.id.dialog_img);
dialog_name_tv.setText(mData.get(vHolder.getAdapterPosition()).getName());
dialog_phone_tv.setText(mData.get(vHolder.getAdapterPosition()).getPhone());
dialog_contact_img.setImageResource(mData.get(vHolder.getAdapterPosition()).getPhoto());
//Toast.makeText(mContext, "Test click "+String.valueOf(vHolder.getAdapterPosition()), Toast.LENGTH_SHORT).show();
myDialog.show();
}
});
vHolder.menu_play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
menu_dialog = v.getRootView().findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(v.VISIBLE);
media = new meplayer();
media.initAudio(v.getContext(), mData.get(vHolder.getAdapterPosition()).getURL());
MainActivity.setMargins(v.getRootView().findViewById(R.id.viewpager_id), 0,0,0,100);
}
});
return vHolder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.tv_name.setText(mData.get(position).getName());
holder.tv_author.setText(mData.get(position).getPhone());
holder.img.setImageResource(mData.get(position).getPhoto());
}
#Override
public int getItemCount() {
return mData.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private ImageButton item_play;
private LinearLayout menu_play;
private TextView tv_name;
private TextView tv_author;
private TextView tv_url;
private ImageView img;
public MyViewHolder(View itemView) {
super(itemView);
item_play = itemView.findViewById(R.id.info_id);
menu_play = itemView.findViewById(R.id.list_item_id);
tv_name = (TextView) itemView.findViewById(R.id.name_list);
tv_author = (TextView) itemView.findViewById(R.id.author_list);
img = (ImageView) itemView.findViewById(R.id.img_contact);
}
}
}
fragmentList
package etes.xddda.music;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class fragmentList extends Fragment {
View v;
private RecyclerView myrecyclerview;
private List<mList> lstContact;
private String URL_JSON = "https://pastebin.com/raw/fG3zd40U";
private JsonArrayRequest ArrayRequest;
private RequestQueue requestQueue ;
public fragmentList() {
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
v = inflater.inflate(R.layout.list_fragment,container,false);
myrecyclerview = (RecyclerView) v.findViewById(R.id.list_recyclerview);
RecyclerViewAdapter recyclerViewAdapter = new RecyclerViewAdapter(getContext(), lstContact);
myrecyclerview.setLayoutManager(new LinearLayoutManager(getActivity()));
myrecyclerview.setAdapter(recyclerViewAdapter);
return v;
}
#Override
public void onCreate(#Nullable Bundle savedInstaceState) {
super.onCreate(savedInstaceState);
_JSONcall();
}
public void _JSONcall() {
lstContact = new ArrayList<>();
ArrayRequest = new JsonArrayRequest(URL_JSON, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
JSONObject jsonObject = null;
for (int i = 0 ; i<response.length();i++) {
try {
jsonObject = response.getJSONObject(i);
lstContact.add(new mList(jsonObject.getString("name"), jsonObject.getString("description"), jsonObject.getString("link"), R.drawable.ic_play_circle_filled_black_24dp));
}
catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getActivity(), "Error 1!",
Toast.LENGTH_LONG).show();
}
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getActivity(), "Error 3!",
Toast.LENGTH_LONG).show();
}
});
requestQueue = Volley.newRequestQueue(getActivity().getApplicationContext());
requestQueue.add(ArrayRequest);
}
}
MainActivity
package etes.xddda.music;
import android.annotation.SuppressLint;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity {
private DrawerLayout nDrawerLayout;
private ActionBarDrawerToggle mToggle;
private TabLayout tabLayout;
private ViewPager viewPager;
private viewPagerAdapter adapter;
public LinearLayout menu_dialog;
private String player_status = "playing";
private ImageButton player_img;
#SuppressLint("RestrictedApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nDrawerLayout = findViewById(R.id.drawer);
menu_dialog = findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(View.GONE);
player_img = findViewById(R.id.playorpause);
player_img.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//setMargins(viewPager, 0,0,0,110);
if (player_status == "playing") {
player_img.setImageResource(R.drawable.ic_play_arrow_black_24dp);
meplayer.pauseAudio();
player_status = "paused";
} else {
player_img.setImageResource(R.drawable.ic_pause_black_24dp);
meplayer.startAudio();
player_status = "playing";
}
}
});
//menu_dialog.setLayoutParams(new LinearLayout.LayoutParams(0, 0));
mToggle = new ActionBarDrawerToggle(this, nDrawerLayout, R.string.open, R.string.close);
nDrawerLayout.addDrawerListener(mToggle);
getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
tabLayout = findViewById(R.id.tablayout_id);
viewPager = findViewById(R.id.viewpager_id);
//viewPager.setLayoutParams(new ViewPager.LayoutParams(0, 0));
//setMarginBottom(viewPager, 0);
setMargins(viewPager, 0,0,0,0);
adapter = new viewPagerAdapter(getSupportFragmentManager());
//Add fragments here
adapter.addFragment(new fragmentList(), ""); //Lista de música
adapter.addFragment(new fragmentFrequent(), ""); //Frequentes
adapter.addFragment(new fragmentPlayList(), ""); //Playlist
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
tabLayout.getTabAt(0).setIcon(R.drawable.ic_music_note_black_24dp); //Lista de música
tabLayout.getTabAt(1).setIcon(R.drawable.ic_filter_list_black_24dp); // Frequentes
tabLayout.getTabAt(2).setIcon(R.drawable.ic_queue_music_black_24dp); // Playlist
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mToggle.syncState();
}
public static void setMargins (View v, int l, int t, int r, int b) {
if (v.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
p.setMargins(l, t, r, b);
v.requestLayout();
}
}
}
mList
package etes.xddda.music;
public class mList {
private String Name;
private String Author;
private String URL;
private int Photo;
public mList() {
}
public mList(String name, String phone, String url, int photo) {
Name = name;
Author = phone;
URL = url;
Photo = photo;
}
//Get User
public String getName() {
return Name;
}
public String getPhone() {
return Author;
}
public String getURL() {
return URL;
}
public int getPhoto() {
return Photo;
}
//Setter
public void setName(String name) {
Name = name;
}
public void setPhone(String phone) {
Author = phone;
}
public void setURL(String url) {
URL = url;
}
public void setPhoto(int photo) {
Photo = photo;
}
}
There are no errors in this script, the app just crash when audio finishes. The problem is related to line menu_dialog.setVisibility(View.GONE); and I have already defined menu_dialog in onCreate. So, can you help me?
P.S.: menu_dialog belongs to activity_main.xml
Thank you!
Remove the local variable menu_dialog that you have defined inside the OnCompletionListener:
package etes.xddda.music;
import android.app.Activity;
import android.content.Context;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Toast;
public class meplayer extends Activity {
public static MediaPlayer mediaPlayer;
public LinearLayout menu_dialog;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
menu_dialog = findViewById(R.id.menu_dialog);
}
public void initAudio(final Context context, final String url) {
if (mediaPlayer == null) {
mediaPlayer = MediaPlayer.create(context, Uri.parse(url));
}
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
//public LinearLayout menu_dialog; REMOVE THIS
#Override
public void onCompletion(MediaPlayer mp) {
//Toast.makeText(context, "TEST", Toast.LENGTH_LONG).show();
killMediaPlayer();
menu_dialog.setVisibility(View.GONE);
}
});
mediaPlayer.start();
}
private void killMediaPlayer() {
if (mediaPlayer != null) {
try {
mediaPlayer.reset();
mediaPlayer.release();
mediaPlayer = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 4 years ago.
I'm spending the last 5 days trying solve this problem. I really do not have any idea about how to solve it. I'm getting Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference. Check my code:
RecyclerView.java
package etes.xdda.music;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.media.MediaPlayer;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.List;
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> implements View.OnClickListener{
Context mContext;
List<mList> mData;
Dialog myDialog;
private MediaPlayer mediaPlayer;
private int playbackPosition=0;
private LinearLayout menu_dialog;
public RecyclerViewAdapter(Context mContext, List<mList> mData) {
this.mContext = mContext;
this.mData = mData;
}
public void onClick(View view) {
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v;
v = LayoutInflater.from(mContext).inflate(R.layout.item_list, parent, false);
final MyViewHolder vHolder = new MyViewHolder(v);
// Dialog ini
myDialog = new Dialog(mContext);
myDialog.setContentView(R.layout.dialog);
myDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
vHolder.item_play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
TextView dialog_name_tv = (TextView) myDialog.findViewById(R.id.dialog_name_id);
TextView dialog_phone_tv = (TextView) myDialog.findViewById(R.id.dialog_author_id);
ImageView dialog_contact_img = (ImageView) myDialog.findViewById(R.id.dialog_img);
dialog_name_tv.setText(mData.get(vHolder.getAdapterPosition()).getName());
dialog_phone_tv.setText(mData.get(vHolder.getAdapterPosition()).getPhone());
dialog_contact_img.setImageResource(mData.get(vHolder.getAdapterPosition()).getPhoto());
//Toast.makeText(mContext, "Test click "+String.valueOf(vHolder.getAdapterPosition()), Toast.LENGTH_SHORT).show();
myDialog.show();
}
});
vHolder.menu_play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
menu_dialog = v.getRootView().findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(v.VISIBLE);
MainActivity a = new MainActivity();
a.initAudio(v.getContext(), mData.get(vHolder.getAdapterPosition()).getURL());
MainActivity.setMargins(v.getRootView().findViewById(R.id.viewpager_id), 0,0,0,100);
}
});
return vHolder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.tv_name.setText(mData.get(position).getName());
holder.tv_author.setText(mData.get(position).getPhone());
holder.img.setImageResource(mData.get(position).getPhoto());
}
#Override
public int getItemCount() {
return mData.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private ImageButton item_play;
private LinearLayout menu_play;
private TextView tv_name;
private TextView tv_author;
private TextView tv_url;
private ImageView img;
public MyViewHolder(View itemView) {
super(itemView);
item_play = itemView.findViewById(R.id.info_id);
menu_play = itemView.findViewById(R.id.list_item_id);
tv_name = (TextView) itemView.findViewById(R.id.name_list);
tv_author = (TextView) itemView.findViewById(R.id.author_list);
img = (ImageView) itemView.findViewById(R.id.img_contact);
}
}
}
Note that I'm invoking MainActivity.java in this part:
vHolder.menu_play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
menu_dialog = v.getRootView().findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(v.VISIBLE);
MainActivity a = new MainActivity();
a.initAudio(v.getContext(), mData.get(vHolder.getAdapterPosition()).getURL());
MainActivity.setMargins(v.getRootView().findViewById(R.id.viewpager_id), 0,0,0,100);
}
});
And here's my MainActivity.java
package etes.xdda.music;
import android.annotation.SuppressLint;
import android.content.Context;
import android.media.MediaPlayer;
import android.net.Uri;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity {
private DrawerLayout nDrawerLayout;
private ActionBarDrawerToggle mToggle;
private TabLayout tabLayout;
private ViewPager viewPager;
private viewPagerAdapter adapter;
public LinearLayout menu_dialog;
private String player_status = "playing";
private ImageButton player_img;
private static MediaPlayer mediaPlayer;
#SuppressLint("RestrictedApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nDrawerLayout = findViewById(R.id.drawer);
menu_dialog = findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(View.GONE);
player_img = findViewById(R.id.playorpause);
player_img.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//setMargins(viewPager, 0,0,0,110);
if (player_status == "playing") {
player_img.setImageResource(R.drawable.ic_play_arrow_black_24dp);
meplayer.pauseAudio();
player_status = "paused";
} else {
player_img.setImageResource(R.drawable.ic_pause_black_24dp);
meplayer.startAudio();
player_status = "playing";
}
}
});
//menu_dialog.setLayoutParams(new LinearLayout.LayoutParams(0, 0));
mToggle = new ActionBarDrawerToggle(this, nDrawerLayout, R.string.open, R.string.close);
nDrawerLayout.addDrawerListener(mToggle);
getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
tabLayout = findViewById(R.id.tablayout_id);
viewPager = findViewById(R.id.viewpager_id);
//viewPager.setLayoutParams(new ViewPager.LayoutParams(0, 0));
//setMarginBottom(viewPager, 0);
setMargins(viewPager, 0,0,0,0);
adapter = new viewPagerAdapter(getSupportFragmentManager());
//Add fragments here
adapter.addFragment(new fragmentList(), ""); //Lista de música
adapter.addFragment(new fragmentFrequent(), ""); //Frequentes
adapter.addFragment(new fragmentPlayList(), ""); //Playlist
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
tabLayout.getTabAt(0).setIcon(R.drawable.ic_music_note_black_24dp); //Lista de música
tabLayout.getTabAt(1).setIcon(R.drawable.ic_filter_list_black_24dp); // Frequentes
tabLayout.getTabAt(2).setIcon(R.drawable.ic_queue_music_black_24dp); // Playlist
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mToggle.syncState();
}
public static void setMargins (View v, int l, int t, int r, int b) {
if (v.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
p.setMargins(l, t, r, b);
v.requestLayout();
}
}
public void initAudio(final Context context, final String url) {
if (mediaPlayer == null) {
mediaPlayer = MediaPlayer.create(context, Uri.parse(url));
}
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
#Override
public void onCompletion(MediaPlayer mp) {
//Toast.makeText(context, "TEST", Toast.LENGTH_LONG).show();
killMediaPlayer();
updateLayout();
}
});
mediaPlayer.start();
}
private static void killMediaPlayer() {
if (mediaPlayer != null) {
try {
mediaPlayer.reset();
mediaPlayer.release();
mediaPlayer = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
private void updateLayout() {
try {
menu_dialog = findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(View.GONE);
} catch (Exception e) {
e.printStackTrace();
}
}
And the part of code that is giving crash is this:
private void updateLayout() {
try {
menu_dialog = findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(View.GONE);
} catch (Exception e) {
e.printStackTrace();
}
}
#edit: I have added this piece of code, I don't know if can help
fragmentList.java
package etes.xdda.music;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class fragmentList extends Fragment {
View v;
private RecyclerView myrecyclerview;
private List<mList> lstContact;
private String URL_JSON = "https://pastebin.com/raw/fG3zd40U";
private JsonArrayRequest ArrayRequest;
private RequestQueue requestQueue ;
MainActivity activity;
public fragmentList() {
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
v = inflater.inflate(R.layout.list_fragment,container,false);
myrecyclerview = (RecyclerView) v.findViewById(R.id.list_recyclerview);
RecyclerViewAdapter recyclerViewAdapter = new RecyclerViewAdapter(activity, lstContact);
myrecyclerview.setLayoutManager(new LinearLayoutManager(getActivity()));
myrecyclerview.setAdapter(recyclerViewAdapter);
return v;
}
#Override
public void onCreate(#Nullable Bundle savedInstaceState) {
super.onCreate(savedInstaceState);
_JSONcall();
}
public void _JSONcall() {
lstContact = new ArrayList<>();
ArrayRequest = new JsonArrayRequest(URL_JSON, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
JSONObject jsonObject = null;
for (int i = 0 ; i<response.length();i++) {
try {
jsonObject = response.getJSONObject(i);
lstContact.add(new mList(jsonObject.getString("name"), jsonObject.getString("description"), jsonObject.getString("link"), R.drawable.ic_play_circle_filled_black_24dp));
}
catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getActivity(), "Error 1!",
Toast.LENGTH_LONG).show();
}
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getActivity(), "Error 3!",
Toast.LENGTH_LONG).show();
}
});
requestQueue = Volley.newRequestQueue(getActivity().getApplicationContext());
requestQueue.add(ArrayRequest);
}
}
Please, help me, I have no more ideas about what I should do. Thank you
Just taking a look at your code, it looks like you are doing many things wrong. Such as this line
MainActivity a = new MainActivity();
You can't instantiate lifecycle components like Services, Activities, Fragments etc this way. Android provides you these components when you call start methods etc. The activity that is created as a result of the above line doesn't go through the lifecycle calls that an activity that is started via using startActivity. As a result, the setContentView of the activity is never called and you get this error. You have to remove this line and implement this properly and the error will go away.
Also just to add, you are actually creating a new instance of the activity when one is already running when you need to call the methods on the old instance that was started.
Edit: Try like this.
MainActivity activity;
List<mList> mData;
Dialog myDialog;
private MediaPlayer mediaPlayer;
private int playbackPosition=0;
private LinearLayout menu_dialog;
public RecyclerViewAdapter(MainActivity activity, List<mList> mData) {
this.activity = activity;
this.mData = mData;
}
And then
vHolder.menu_play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
menu_dialog = v.getRootView().findViewById(R.id.menu_dialog);
menu_dialog.setVisibility(v.VISIBLE);
activity.initAudio(v.getContext(), mData.get(vHolder.getAdapterPosition()).getURL());
activity.setMargins(v.getRootView().findViewById(R.id.viewpager_id), 0,0,0,100);
}
});
Also remove static from the main activity functions
i am working of live search with MySQL, JSON. its working fine with local array values. but not working with MySQL. my concern is when user start typing it has to search from data base and show it in listview. bellow is my Adapter for search
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import zesteve.com.myapplication.R;
import zesteve.com.myapplication.Search;
import zesteve.com.myapplication.VendProfileActivity;
/**
* Created by Ravi Shankar on 6/22/2017.
*/
public class SearchAdapter extends BaseAdapter {
// Declare Variables
Context mContext;
LayoutInflater inflater;
private List<Search> vendersearchlist = null;
private ArrayList<Search> arraylist;
public SearchAdapter(Context context,
List<Search> vendersearchlist) {
mContext = context;
this.vendersearchlist = vendersearchlist;
inflater = LayoutInflater.from(mContext);
this.arraylist = new ArrayList<Search>();
this.arraylist.addAll(vendersearchlist);
}
public class ViewHolder {
TextView id;
TextView vname;
}
#Override
public int getCount() {
return vendersearchlist.size();
}
#Override
public Search getItem(int position) {
return vendersearchlist.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
public View getView(final int position, View view, ViewGroup parent) {
final ViewHolder holder;
if (view == null) {
holder = new ViewHolder();
view = inflater.inflate(R.layout.search_item_list, null);
// Locate the TextViews in listview_item.xml
//holder.id = (TextView) view.findViewById(R.id.id);
holder.vname = (TextView) view.findViewById(R.id.autoCompleteTextView);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
// Set the results into TextViews
//holder.rank.setText(Search.get(position).getRank());
holder.vname.setText(vendersearchlist.get(position).getVname());
// Listen for ListView Item Click
view.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// Send single item click data to SingleItemView Class
Intent intent = new Intent(mContext, VendProfileActivity.class);
// Pass all data rank
intent.putExtra("Vend_Id",
(vendersearchlist.get(position).getId()));
// Pass all data country
intent.putExtra("Vend_Name",
(vendersearchlist.get(position).getVname()));
// Pass all data population
// Start SingleItemView Class
mContext.startActivity(intent);
}
});
return view;
}
// Filter Class
public void filter(String charText) {
charText = charText.toLowerCase(Locale.getDefault());
vendersearchlist.clear();
if (charText.length() == 0) {
vendersearchlist.addAll(arraylist);
} else {
for (Search sl : arraylist) {
if (sl.getVname().toLowerCase(Locale.getDefault())
.contains(charText)) {
vendersearchlist.add(sl);
}
}
}
notifyDataSetChanged();
}
}
AND POJO
public class Search {
private int id;
private String vname;
public Search(int id, String vname) {
this.id = id;
this.vname = vname;
}
public int getId() {
return this.id;
}
public String getVname() {
return this.vname;
}
}
And my SearchActivity.java
import android.content.res.Resources;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.TypedValue;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import okhttp3.OkHttpClient;
import okhttp3.Response;
import zesteve.com.myapplication.adapter.SearchAdapter;
import zesteve.com.myapplication.adapter.VenderAdapter;
public class Search_vender extends AppCompatActivity {
String catname,city;
int catid;
private EditText Vendname;
private Session session;
ListView listview;
SearchAdapter adapter;
int[] id;
String[] vname;
ArrayList<Search> vendersearchlist = new ArrayList<Search>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_vender);
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
session = new Session(Search_vender.this);
catid = getIntent().getIntExtra("CatId",00);
catname= getIntent().getStringExtra("CatName");
city = session.getUserLocation().get(session.KEY_UCITY);
listview = (ListView) findViewById(R.id.listview);
Vendname = (EditText) findViewById(R.id.searchitem);
Vendname.setHint("Search "+catname+" in "+city);
//fetch data from server in json
String vsearch = Vendname.getText().toString();
prepareVender(vsearch);
// Pass results to ListViewAdapter Class
adapter = new SearchAdapter(this, vendersearchlist);
// Binds the Adapter to the ListView
listview.setAdapter(adapter);
// Locate the EditText in listview_main.xml
Vendname.addTextChangedListener(new TextWatcher() {
#Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
String text = Vendname.getText().toString().toLowerCase(Locale.getDefault());
adapter.filter(text);
}
#Override
public void beforeTextChanged(CharSequence arg0, int arg1,
int arg2, int arg3) {
// TODO Auto-generated method stub
}
#Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
});
}
private void prepareVender(String sText){
AsyncTask<String,Void,Void> task = new AsyncTask<String, Void, Void>() {
#Override
protected Void doInBackground(String... strings) {
OkHttpClient client = new OkHttpClient();
okhttp3.Request request = new okhttp3.Request.Builder()
.url("http://api.zesteve.com/vend_list.php?city="+city+"&catid="+catid+"&name="+strings[0])
.build();
try{
Response response = client.newCall(request).execute();
JSONArray array = new JSONArray(response.body().string());
for (int i=0; i<array.length(); i++){
JSONObject object= array.getJSONObject(i);
Search vender = new Search(object.getInt("id"),
object.getString("name"));
vendersearchlist.add(vender);
}
}catch (IOException e){
e.printStackTrace();
} catch (JSONException e) {
System.out.println("End of Catagory");
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
adapter.notifyDataSetChanged();
}
};
task.execute(sText);
}
#Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
}
Please comment if you have any doubts.
if Somebody looking for same Solution. bellow is my code
public class Search_vender extends AppCompatActivity {
String catname,city;
int catid;
SearchView Vendname;
private Session session;
ListView listview;
SearchAdapter adapter;
ArrayList<Search> vendersearchlist = new ArrayList<Search>();
ArrayList<Search> filteredSearchResults = new ArrayList<Search>();
ProgressDialog progressDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_vender);
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
session = new Session(Search_vender.this);
progressDialog = new ProgressDialog(Search_vender.this);
progressDialog.setCancelable(false);
catid = getIntent().getIntExtra("CatId",00);
catname= getIntent().getStringExtra("CatName");
city = session.getUserLocation().get(session.KEY_UCITY);
//Toast.makeText(Search_vender.this,catid + city,Toast.LENGTH_LONG).show();
listview = (ListView) findViewById(R.id.listview);
Vendname = (SearchView) findViewById(R.id.searchitem);
Vendname.setQueryHint("Search "+catname+" in "+city);
Vendname.setOnQueryTextFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View v, boolean hasFocus) {
// TODO Auto-generated method stub
//Toast.makeText(Search_vender.this, String.valueOf(hasFocus),Toast.LENGTH_SHORT).show();
}
});
Vendname.setOnQueryTextListener(new OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
// TODO Auto-generated method stub
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
if(newText.length() > 2){
listview.setVisibility(View.VISIBLE);
GetDataVender gv = (GetDataVender) new GetDataVender().execute(newText);
}else{
listview.setVisibility(View.INVISIBLE);
}
return false;
}
});
}
public void filterSearchArray(String newText){
String pName;
filteredSearchResults.clear();
for (int i = 0; i < vendersearchlist.size(); i++)
{
pName = vendersearchlist.get(i).getVname().toLowerCase();
if ( pName.contains(newText.toLowerCase()))
{
filteredSearchResults.add(vendersearchlist.get(i));
}
}
}
class GetDataVender extends AsyncTask<String, Void, String>{
String textsearch;
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog.setMessage("Loading Please Wait...");
showDialog();
}
#Override
protected String doInBackground(String... strings) {
OkHttpClient client = new OkHttpClient();
okhttp3.Request request = new okhttp3.Request.Builder()
.url("http://api.zesteve.com/autosearch.php?city="+city+"&catid="+catid+"&name="+strings[0])
.build();
this.textsearch = strings[0];
try {
Response response = client.newCall(request).execute();
JSONArray array = new JSONArray(response.body().string());
for (int i=0; i<array.length(); i++){
JSONObject object =array.getJSONObject(i);
Search catagory = new Search(object.getInt("id"),
object.getString("name"));
vendersearchlist.add(catagory);
}
}catch (IOException e){
e.printStackTrace();
} catch (JSONException e) {
System.out.println("End of Catagory");
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if(result != null && result.equalsIgnoreCase("Exception Caught")){
Toast.makeText(Search_vender.this, "Unable to connect to server,please try later", Toast.LENGTH_LONG).show();
hideDialog();
}else{
filterSearchArray(textsearch);
listview.setAdapter(new SearchAdapter(Search_vender.this,filteredSearchResults));
hideDialog();
}
//hideDialog();
//adapter.notifyDataSetChanged();
}
}
private void showDialog() {
if (!progressDialog.isShowing())
progressDialog.show();
}
private void hideDialog() {
if (progressDialog.isShowing())
progressDialog.dismiss();
}
#Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
}
it works when user stat search from second character.
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
I have created a movie application that queries a REST API at themoviedb.org. On selecting a movie from a grid the user is brought to a details screen where further details about the movie are shown details being a list of trailers and a list of reviews. The problem is that SOMETIMES my code for populating the list of reviews and trailers hits a NullPointerException. It doesn't happen alway and it's not specific to a particular movie entry, it's totally random.
To be precise, I randomly get NullPointerExceptions when I am refreshing my RecyclerView Adapter with data inside the runOnUIThread() after a succesful network response.
Here's the GitHub repo link-https://github.com/Hackertronix/Project-Motion/tree/Stage_2
Following is my code along with the stack trace
I have added comments to show the line numbers
DetailsFragment.java
package com.execube.genesis.views.fragments;
import android.annotation.TargetApi;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.Typeface;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.CardView;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TextView;
import android.widget.Toast;
import com.execube.genesis.R;
import com.execube.genesis.model.Event;
import com.execube.genesis.model.Movie;
import com.execube.genesis.model.Review;
import com.execube.genesis.model.Trailer;
import com.execube.genesis.utils.API;
import com.execube.genesis.utils.EventBus;
import com.execube.genesis.utils.JSONParser;
import com.execube.genesis.utils.OkHttpHandler;
import com.orm.SugarRecord;
import com.squareup.picasso.Picasso;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import okhttp3.Call;
import okhttp3.Response;
import static com.execube.genesis.R.drawable.ic_favorite_black_24dp;
/**
* Created by Prateek Phoenix on 4/30/2016.
*/
public class DetailsFragment extends Fragment {
private static final String TAG = "DETAILS";
private static final int DEFAULT_NUM_COLORS = 5;
private Movie mMovie;
private Movie entry,tempMovie;
private List<Movie> movie;
public Intent intent;
private TextView mDetailTitle;
private TextView mReleaseDate;
private TextView mOverview;
private TextView mOverviewHeader;
private TextView mReviesHeader;
private TextView mTrailersHeader;
private ImageView mBackdrop;
private Toolbar mToolbar;
private RatingBar mRatingBar;
private ArrayList<Review> mReviews=new ArrayList<>();
private ArrayList<Trailer> mTrailers=new ArrayList<>();
private List<Movie> updatedFavsList= new ArrayList<>();
public static final String MOVIE_REVIEWS_ARRAY ="movie_details";
private static final String MOVIE_TRAILERS_ARRAY = "movie_reviews";
private Typeface fontBold;
private Typeface fontMediumLight;
private Typeface fontMedium;
private RecyclerView mReviewRecyclerView;
private RecyclerView mTrailerRecyclerView;
private ProgressBar mReviewsProgressbar;
private ProgressBar mTrailersProgressbar;
private CoordinatorLayout mCoordinatorLayout;
private CardView mReviewsCardView;
private FloatingActionButton mFloatingActionButton;
private ReviewsAdapter mReviewAdapter;
private int NumOfReviews;
private TrailersAdapter mTrailerAdapter;
private String id;
private boolean isFav;
public DetailsFragment() {
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void onSaveInstanceState(Bundle outState) {
Log.v(TAG,"Saving state in onSaveInstanceState");
outState.putParcelableArrayList(MOVIE_REVIEWS_ARRAY,mReviews);
outState.putParcelableArrayList(MOVIE_TRAILERS_ARRAY,mTrailers);
super.onSaveInstanceState(outState);
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_detail, container, false);
mBackdrop = (ImageView) view.findViewById(R.id.details_poster);
mDetailTitle = (TextView) view.findViewById(R.id.detail_title_text);
mReleaseDate = (TextView) view.findViewById(R.id.release_date);
mOverview = (TextView) view.findViewById(R.id.overview);
mOverviewHeader = (TextView) view.findViewById(R.id.overview_header);
mReviesHeader=(TextView)view.findViewById(R.id.review_header);
mTrailersHeader=(TextView)view.findViewById(R.id.trailer_header);
mRatingBar = (RatingBar) view.findViewById(R.id.movie_rating);
mCoordinatorLayout=(CoordinatorLayout)view.findViewById(R.id.coordinator_layout);
mReviewRecyclerView= (RecyclerView)view.findViewById(R.id.review_recycler_view);
mTrailerRecyclerView=(RecyclerView)view.findViewById(R.id.trailer_recycler_view);
mReviewsProgressbar=(ProgressBar)view.findViewById(R.id.reviews_progressbar);
mTrailersProgressbar=(ProgressBar)view.findViewById(R.id.trailers_progressbar);
mFloatingActionButton=(FloatingActionButton)view.findViewById(R.id.fab);
mReviewsCardView= (CardView) view.findViewById(R.id.reviews_card);
intent = getActivity().getIntent();
Bundle bundle=getArguments();
mMovie=bundle.getParcelable("PARCEL");
tempMovie=mMovie;
id = String.valueOf(mMovie.getMovieId());
checkFav();
mFloatingActionButton.show();
assert mMovie != null;
//PREPPING THE URL FOR QUERY
String reviewQueryUrl = API.MOVIES_BASE_URL + id + "/reviews" + API.API_KEY;
String trailerQueryUrl = API.MOVIES_BASE_URL + id + "/videos" + API.API_KEY;
mDetailTitle.setText(mMovie.getTitle());
mReleaseDate.setText(mMovie.getReleaseDate());
mRatingBar.setProgress((int) mMovie.getVoteAverage());
mOverview.setText(mMovie.getOverview());
if (Build.VERSION.SDK_INT != 21) {
fontBold = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Gotham-Rounded-Bold.ttf");
fontMedium = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Gotham-Rounded-Medium.ttf");
fontMediumLight = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Gotham-Rounded-Book_.ttf");
mDetailTitle.setTypeface(fontBold);
mReleaseDate.setTypeface(fontMedium);
mOverview.setTypeface(fontMediumLight);
mOverviewHeader.setTypeface(fontBold);
mReviesHeader.setTypeface(fontBold);
mTrailersHeader.setTypeface(fontBold);
}
//FETCHING JSON HERE
if(savedInstanceState!=null&&savedInstanceState.containsKey(MOVIE_REVIEWS_ARRAY))
{
Log.v(TAG,"Restoring from bundle");
mReviews=savedInstanceState.getParcelableArrayList(MOVIE_REVIEWS_ARRAY);
mTrailers=savedInstanceState.getParcelableArrayList(MOVIE_TRAILERS_ARRAY);
mReviewsProgressbar.setVisibility(View.GONE);
mTrailersProgressbar.setVisibility(View.GONE);
}
else {
OkHttpHandler reviewsHandler = new OkHttpHandler(reviewQueryUrl, reviewsCallback);
reviewsHandler.fetchData();
OkHttpHandler trailersHandler= new OkHttpHandler(trailerQueryUrl, trailersCallback);
trailersHandler.fetchData();
}
Picasso.with(getActivity()).load(API.IMAGE_URL + API.IMAGE_SIZE_500 + mMovie.getPosterPath())
.placeholder(R.drawable.placeholder)
.error(R.drawable.error)
.into(mBackdrop);
getActivity().startPostponedEnterTransition();
mReviewRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
mReviewAdapter= new ReviewsAdapter();
mReviewRecyclerView.setAdapter(mReviewAdapter);
LinearLayoutManager layoutmanager= new LinearLayoutManager(getActivity(),LinearLayoutManager.HORIZONTAL,false);
mTrailerRecyclerView.setLayoutManager(layoutmanager);
mTrailerAdapter= new TrailersAdapter();
mTrailerRecyclerView.setAdapter(mTrailerAdapter);
return view;
}
private void checkFav() {
movie=new ArrayList<>();
movie=SugarRecord.find(Movie.class,"m_id=?",id);
if(movie.size()==0)
{
Log.v(TAG,"Null");
mFloatingActionButton.setImageResource(R.drawable.ic_favorite_border_black_24dp);
}
else {
Log.v(TAG,"NOT Null");
mFloatingActionButton.setImageResource(R.drawable.ic_favorite_black_24dp);
}
mFloatingActionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
movie=SugarRecord.find(Movie.class,"m_id=?",id);
if(movie.size()>0)
{
entry = movie.get(0);
entry.delete();
Event event = new Event("Database has been modified!!");
EventBus.getBus().post(event);
mFloatingActionButton.setImageResource(R.drawable.ic_favorite_border_black_24dp);
Snackbar snackbar = Snackbar.make(mCoordinatorLayout,"Movie removed from Favourites!!",Snackbar.LENGTH_SHORT);
View view= snackbar.getView();
TextView textView = (TextView)view.findViewById(android.support.design.R.id.snackbar_text);
textView.setTextColor(Color.YELLOW);
snackbar.show();
}
else
{
entry = tempMovie;
entry.save();
Event event = new Event("Database has been modified!!");
EventBus.getBus().post(event);
mFloatingActionButton.setImageResource(R.drawable.ic_favorite_black_24dp);
Snackbar snackbar = Snackbar.make(mCoordinatorLayout,"Movie added to Favourites!!",Snackbar.LENGTH_SHORT);
View view= snackbar.getView();
TextView textView = (TextView)view.findViewById(android.support.design.R.id.snackbar_text);
textView.setTextColor(Color.YELLOW);
snackbar.show();
}
}
});
}
//OKHTTP CALLBACK FOR NETWORK CALL
private okhttp3.Callback reviewsCallback = new okhttp3.Callback() {
#Override
public void onFailure(Call call, IOException e) {
//TODO handle failure on UI thread
}
#Override
public void onResponse(Call call, Response response) throws IOException {
try {
String JSONData= response.body().string();
JSONObject jsonObject = new JSONObject(JSONData);
NumOfReviews = jsonObject.getInt("total_results");
JSONParser parser = new JSONParser();
mReviews=parser.parseReviews(JSONData);
} catch (JSONException e) {}
getActivity().runOnUiThread(new Runnable() {
#Override //THIS IS THE FIRST LINE WHERE I GET A NULL POINTER EXCEPTION
public void run() {
if(mReviewAdapter!=null)
{
mReviewsProgressbar.setVisibility(View.GONE);
mReviewAdapter.notifyDataSetChanged();
}
}
});
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
if (NumOfReviews==0)
{
mReviewsCardView.setVisibility(View.INVISIBLE);
}
}
});
}
};
private okhttp3.Callback trailersCallback = new okhttp3.Callback() {
#Override
public void onFailure(Call call, IOException e) {
//TODO handle failure on UI thread
}
#Override
public void onResponse(Call call, Response response) throws IOException {
try {
String json1= response.body().string();
JSONParser parser= new JSONParser();
mTrailers = parser.parseTrailers(json1);
} catch (JSONException e) {}
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() { //THIS IS THE 2nd LINE WHERE I GET A NULL POINTER EXCEPTION
if(mTrailerAdapter!=null)
{
mTrailersProgressbar.setVisibility(View.GONE);
mTrailerAdapter.notifyDataSetChanged();
}
}
});
}
};
private class ReviewViewHolder extends RecyclerView.ViewHolder{
private TextView mAuthorText;
private TextView mReviewText;
private Review mReview;
public ReviewViewHolder(View itemView) {
super(itemView);
mAuthorText= (TextView) itemView.findViewById(R.id.author_textview);
mReviewText= (TextView) itemView.findViewById(R.id.review_textview);
}
public void bind(Review review)
{
mReview= review;
mAuthorText.setText(mReview.getAuthor());
mReviewText.setText(mReview.getContent());
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.LOLLIPOP)
{
mAuthorText.setTypeface(fontBold);
mReviewText.setTypeface(fontMediumLight);
}
}
}
private class ReviewsAdapter extends RecyclerView.Adapter<ReviewViewHolder>{
#Override
public ReviewViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view= LayoutInflater.from(getActivity()).inflate(R.layout.review_item,parent,false);
return new ReviewViewHolder(view);
}
#Override
public void onBindViewHolder(ReviewViewHolder holder, int position) {
Review review= mReviews.get(position);
holder.bind(review);
}
#Override
public int getItemCount() {
if(mReviews==null)
{ return 0;}
else
{return mReviews.size();}
}
}
private class TrailerViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private ImageView mTrailerThumbnail;
private Trailer mTrailer;
public TrailerViewHolder(View itemView) {
super(itemView);
mTrailerThumbnail=(ImageView)itemView.findViewById(R.id.trailer_thumbnail);
itemView.setOnClickListener(this);
}
public void bind(Trailer trailer)
{
mTrailer=trailer;
Picasso picasso =Picasso.with(getActivity());
picasso.setIndicatorsEnabled(true);
picasso.load(API.YOUTUBE_THUMBNAIL_URL+mTrailer.getKey()+API.THUMBNAIL_QUALITY)
.into(mTrailerThumbnail);
}
#Override
public void onClick(View v) {
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(API.YOUTUBE_TRAILER_URL+mTrailer.getKey()));
startActivity(intent);
}
}
private class TrailersAdapter extends RecyclerView.Adapter<TrailerViewHolder>
{
#Override
public TrailerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view= LayoutInflater.from(getActivity()).inflate(R.layout.trailer_item,parent,false);
return new TrailerViewHolder(view);
}
#Override
public void onBindViewHolder(TrailerViewHolder holder, int position) {
Trailer trailer= mTrailers.get(position);
holder.bind(trailer);
}
#Override
public int getItemCount() {
return mTrailers.size();
}
}
}
Stack Trace
06-10 02:02:30.548 25094-27219/? E/AndroidRuntime: FATAL EXCEPTION: OkHttp Dispatcher
Process: com.execube.genesis, PID: 25094
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.app.FragmentActivity.runOnUiThread(java.lang.Runnable)' on a null object reference
at com.execube.genesis.views.fragments.DetailsFragment$3.onResponse(DetailsFragment.java:349)
at okhttp3.RealCall$AsyncCall.execute(RealCall.java:133)
at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
06-10 02:02:30.548 25094-27218/? E/AndroidRuntime: FATAL EXCEPTION: OkHttp Dispatcher
Process: com.execube.genesis, PID: 25094
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.app.FragmentActivity.runOnUiThread(java.lang.Runnable)' on a null object reference
at com.execube.genesis.views.fragments.DetailsFragment$2.onResponse(DetailsFragment.java:308)
at okhttp3.RealCall$AsyncCall.execute(RealCall.java:133)
at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
When you're calling getActivity, it might return null when the fragment is not attached to any activity. In order to avoid a NullPointerException, be sure to first check if it's not null and then proceed with your logic.
if(getActivity!=null){
//do stuff
}