Develop Reference

Calling onSaveInstanceState on Activity

I inherited a project, trying to understand and solve an old bug.
When I start an activity and let it sit for a bit (sometimes it's almost immediate), but it appears to go into a pause state or something and attempts to reload the activity and gets an error.
"Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String ... ' on a null object reference"
I found that when I add this to my activity:
#Override
public void onSaveInstanceState(Bundle savedInstanceState)
{
//super.onSaveInstanceState(savedInstanceState);
}
It appears to work perfectly.
However, when I uncomment the line above to super.onSaveInstanceState(savedInstanceState);, I get the error again.
My activity is extending the ActionBarActivity, if that is helpful.
Any help would be appreciated. Thank you!
Related Code:
#Override
protected void prepareLayout() {
textMessage = (TextView) findViewById(R.id.textMessage);
textNotes = (EditText) findViewById(R.id.textNotes);
textMessage.setText(getOneOfMyItems().getText());
// ... the above line is where the problem error is thrown.
}
Stack Trace:
Process: com.myproj.myproj, PID: 9272
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myproj.myproj/com.myproj.activities.MyActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.myproj.data.MyItems.getText()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3288)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3384)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:5433)
at android.app.ActivityThread.access$1200(ActivityThread.java:226)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1810)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7270)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.myproj.data.MyItems.getText()' on a null object reference
at com.myproj.xyz.MyFragment.prepareLayout(MyFragment.java:44)
at com.myproj.fragments.BaseFragment.prepareAndSetView(BaseFragment.java:49)
at at com.myproj.xyz.BaseMyFragment.onCreateView(BaseMyFragment.java:21)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2074)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1286)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1268)
at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:2143)
at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:2089)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1129)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1286)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1268)
at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:2143)
at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:201)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:615)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1266)
at android.app.Activity.performStart(Activity.java:6943)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3384) 
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:5433) 
at android.app.ActivityThread.access$1200(ActivityThread.java:226) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1810) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:7270) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 

Android: Using 2 ArrayAdapters Error

I now get a new error.
This is my code:
lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int i, long id) {
Toast.makeText(getApplicationContext(), beaconAdap.getItem(i).toString() + " Added to history", Toast.LENGTH_SHORT).show();
historyBeacons.add(beaconAdap.getItem(i).toString());
Intent intent = new Intent(getBaseContext(), HistoryActivity.class);
intent.putStringArrayListExtra("beacons", historyBeacons);
startActivity(intent);
return true;
}
});
}
So i add the int i to an arraylist, i have tested that it goes in and it does. Then a start a new intent for the history activity and send the arraylist over.
This is the code in history:
ListView historyLv = (ListView) findViewById(R.id.historyView);
ArrayAdapter historyAdap;
ArrayList<String> historyBeacons = getIntent().getExtras().getStringArrayList("beacons");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_history);
historyAdap = new ArrayAdapter(getApplicationContext(), android.R.layout.simple_list_item_1, historyBeacons);
historyLv.setAdapter(historyAdap);
}
But i get this error:
03-18 17:44:41.238 18641-18641/nsa.com.museum E/AndroidRuntime: FATAL EXCEPTION: main
Process: nsa.com.museum, PID: 18641
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{nsa.com.museum/nsa.com.museum.HistoryActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:120)
at android.support.v7.app.AppCompatDelegateImplV9.<init>(AppCompatDelegateImplV9.java:151)
at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:31)
at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:55)
at android.support.v7.app.AppCompatDelegateImplV23.<init>(AppCompatDelegateImplV23.java:33)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:203)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:185)
at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:519)
at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:190)
at nsa.com.museum.HistoryActivity.<init>(HistoryActivity.java:12)
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5417) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
03-18 17:44:43.362 18846-18846/nsa.com.museum W/System: ClassLoader referenced unknown path: /data/app/nsa.com.museum-2/lib/x86_64

can You show the erro please
and I guess you forget to add
ListAdapter.notifyDataSetChanged();
after you add value to lisy
.........................................................
NullPointerException
this erro shows in Android cause you may not Initialized the Adapter
make sure you Initialized the 2nd adapter

realm null object reference

when i start my app with out network and call my data in my database app crash and this is my code
public void getAllMovies() {
findData = realm.where(MovieDb.class).findAll();
movieArrayList = new ArrayList(findData);
movieMethod();
}
and i make my conflagration in here
public class myApplication extends Application {
#Override
public void onCreate() {
super.onCreate();
RealmConfiguration configuration = new RealmConfiguration
.Builder(this).name("Movie_database.realm").build();
Realm.setDefaultConfiguration(configuration);}}
and moviedb is my realm object
my app crash in line
findData = realm.where(MovieDb.class).findAll();
and this is my error
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.massive.movieapp, PID: 4222
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.massive.movieapp/com.massive.movieapp.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'io.realm.RealmQuery io.realm.Realm.where(java.lang.Class)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'io.realm.RealmQuery io.realm.Realm.where(java.lang.Class)' on a null object reference
at com.massive.movieapp.FragmentForActivity.getAllMovies(FragmentForActivity.java:143)
at com.massive.movieapp.FragmentForActivity.CallNetwork(FragmentForActivity.java:62)
at com.massive.movieapp.FragmentForActivity.onCreate(FragmentForActivity.java:55)
at android.app.Fragment.performCreate(Fragment.java:2198)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:942)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1148)
at android.app.BackStackRecord.run(BackStackRecord.java:793)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1535)
at android.app.FragmentController.execPendingActions(FragmentController.java:325)
at android.app.Activity.performStart(Activity.java:6252)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5417) 
at java.lang.reflect.Method.invoke(Native Method

The exception happens because your realm variable is null when you call the getAllMovies method.
Remember to call realm = Realm.getDefaultInstance(); previously.

Trying to set custom font on TextView - nullpointer

I have no underlined code, but as soon as i start my app on emulator, i'm receiving these errors.
FATAL EXCEPTION: main
Process: com.milos.sportisa, PID: 2735
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.milos.sportisa/com.milos.sportisa.SplashActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
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:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference
at com.milos.sportisa.SplashActivity.onCreate(SplashActivity.java:29)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
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:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 
And this is my SplashActivity:
public class SplashActivity extends AppCompatActivity {
private TextView etSportisa;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
/* ButterKnife.inject(this);
mProgressBar.setIndeterminateDrawable(new foldingCirclesDrawable.Builder(this)
.build());
mProgressBar.setIndeterminateDrawable(new foldingCirclesDrawable.Builder(this)
.colors(getResources().getIntArray(R.array.colors) //Array of 4 colors
.build()); */
Typeface myTypeFace = Typeface.createFromAsset(getAssets(), "fonts/esp_ital.ttf");
etSportisa.setTypeface(myTypeFace);
etSportisa = (TextView) findViewById(R.id.tv_sportisa);
final ProgressDialog pd = new ProgressDialog(SplashActivity.this);
pd.setMessage("Učitavanje...");
pd.show();
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
// Actions to do after 10 seconds
pd.dismiss();
Intent i = new Intent(SplashActivity.this, MainActivity.class);
startActivity(i);
}
}, 2000);
}
}
Special font is added in assets\font folder. I also added an image for the loading screen but i think that the font is cousin those issues

Make the following changes to your code:
Typeface myTypeFace = Typeface.createFromAsset(getAssets(), "fonts/esp_ital.ttf");
etSportisa = (TextView) findViewById(R.id.tv_sportisa);
etSportisa.setTypeface(myTypeFace);
After initialization, you can do any operation with any layout.

The problem is here:
etSportisa is null
set it after you findViewByID
Typeface myTypeFace = Typeface.createFromAsset(getAssets(), "fonts/esp_ital.ttf");
etSportisa = (TextView) findViewById(R.id.tv_sportisa);
etSportisa.setTypeface(myTypeFace);

Limit error in Firebase chatting in Android?

Some time ther is not error its run without error but most of time got error in this code, I try many thing for this. I try call this code on onStart() and I try this on onActivityCreted() too. but i get same error. This is my coding for show previous chat. I got error in limit().
final ListView listView = getListView();
mChatListAdapter = new FirebaseListAdapter<>(mFirebaseRef.limit(50), Chat.class, R.layout.chat_item, R.layout.chat_item_other,
R.layout.third_layout_chat, R.layout.fourth_layout_chat, getActivity(), chat_id);
listView.setAdapter(mChatListAdapter);
mChatListAdapter.registerDataSetObserver(new DataSetObserver() {
#Override
public void onChanged() {
super.onChanged();
listView.setSelection(mChatListAdapter.getCount() - 1);
}
});
This is error.
FATAL EXCEPTION: main Process: com.socialapp.android, PID: 8112 Theme: themes:{} java.lang.RuntimeException: Unable to start activity ComponentInfo{com.socialapp.android/com.socialapp.chat.ChatViewActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'com.firebase.client.Query com.firebase.client.Firebase.limit(int)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2450)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5466)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'com.firebase.client.Query com.firebase.client.Firebase.limit(int)' on a null object reference
at com.socialapp.chat.ChatViewFragment.onStart(ChatViewFragment.java:609)
at android.app.Fragment.performStart(Fragment.java:2244)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1002)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1148)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1130)
at android.app.FragmentManagerImpl.dispatchStart(FragmentManager.java:1958)
at android.app.FragmentController.dispatchStart(FragmentController.java:163)
at android.app.Activity.performStart(Activity.java:6274)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2413)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5466) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)