Starting Fragment activity from an activity causes NullPointerException - java

I'm trying to add fragments to the dashboard of my project app. However, I'm getting nullpointerexception
in the .setOnItemSelectedListener in the bottomMenu function, the code is as follows:
Dashboard.java
public class Dashboard extends AppCompatActivity {
ChipNavigationBar chipNavigationBar;
#Override
protected void onCreate(Bundle savedInstanceState) {
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
chipNavigationBar = findViewById(R.id.bottom_nav_menu);
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new DashboardFragment()).commit();
bottomMenu();
}
private void bottomMenu() {
chipNavigationBar.setOnItemSelectedListener(new ChipNavigationBar.OnItemSelectedListener() {
#Override
public void onItemSelected(int i) {
Fragment fragment = null;
switch (i){
case R.id.bottom_nav_dashboard:
fragment = new DashboardFragment();
break;
case R.id.bottom_nav_explore:
fragment = new ExploreFragment();
break;
case R.id.bottom_nav_profile:
fragment = new ProfileFragment();
break;
}
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, fragment).commit();
}
});
}
}
LogCat:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.desikhao, PID: 11751
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.desikhao/com.example.desikhao.LocationOwner.Dashboard}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.ismaeldivita.chipnavigation.ChipNavigationBar.setOnItemSelectedListener(com.ismaeldivita.chipnavigation.ChipNavigationBar$OnItemSelectedListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3308)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3457)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2044)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:224)
at android.app.ActivityThread.main(ActivityThread.java:7562)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.ismaeldivita.chipnavigation.ChipNavigationBar.setOnItemSelectedListener(com.ismaeldivita.chipnavigation.ChipNavigationBar$OnItemSelectedListener)' on a null object reference
at com.example.desikhao.LocationOwner.Dashboard.bottomMenu(Dashboard.java:39)
at com.example.desikhao.LocationOwner.Dashboard.onCreate(Dashboard.java:33)
at android.app.Activity.performCreate(Activity.java:7893)
at android.app.Activity.performCreate(Activity.java:7880)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3283)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3457) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2044) 
at android.os.Handler.dispatchMessage(Handler.java:107) 
at android.os.Looper.loop(Looper.java:224) 
at android.app.ActivityThread.main(ActivityThread.java:7562) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950) 
At first, I thought the problem is because I stored a null value in the fragment, if that is the case then how do I fix it, I'm new to this so please let me know what am I doing wrong here.

Your chipNavigationBar variable is null and therefore the OnItemSelectedListener is instantiated with null, which is not possible.
You try to find your chipNavigationBar in the Dashboard, but you haven't even set setContentView(R.layout.yourLayout);, which means that it is not possible to find the ViewById.
You have to instatiate the variable in your fragment, where you have a valid view.
chipNavigationBar = findViewById(R.id.bottom_nav_menu);

Related

NullPointerException while using TinyDB

I'm new to android (and not a veteran at all in java) developpment.
Trying to do a weather app, I'm trying to use TinyDB as my storage for saved cities.
A button on another activity let me add cities to a list (which I want to save).
In my MainActivity's onCreate, I'm setting up my TinyDB. Then add a city stored in extra to my TinyDB if the MainActivity is launched from the addCityActivity. Finally, getting all the cities from TinyDB to print it to screen in a ListView. (user will then be able to click on a city to get weather information for this one)
But then a NullPointerException raises and it seems to come from TinyDB and I have no idea how to resolve it, I'm stuck on it for a day now (doing this on my free time).
Do you guys have any idea please ?
TinyDB is here.
And here's my MainActivity :
public class MainActivity extends AppCompatActivity {
private Context context;
private ListView cityListView;
private CitylistAdapter citylistAdapter;
private List<City> cities = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TinyDB tinydb = new TinyDB(context);
if (getIntent().getExtras() != null) {
String name = getIntent().getStringExtra("City");
ArrayList<String> cityList = tinydb.getListString("Cities");
cityList.add(getIntent().getStringExtra("City"));
tinydb.putListString("Cities", cityList);
}
ArrayList<String> cityList = tinydb.getListString("Cities");
for (int i = 0; i < cityList.size(); i++) {
City city = new City();
city.setName(cityList.get(i));
cities.add(city);
}
this.cityListView = (ListView) findViewById(R.id.cityList);
this.citylistAdapter = new CitylistAdapter(getApplicationContext(), cities);
this.cityListView.setAdapter(citylistAdapter);
FloatingActionButton addCity = (FloatingActionButton) findViewById(R.id.openAddCity);
addCity.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startAddCityActivity();
}
});
}
private void startAddCityActivity() {
Intent intent = new Intent(this, AddCityActivity.class);
startActivity(intent);
}
}
And here's the stack trace :
2021-09-23 13:59:38.565 5754-5754/com.example.weather E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.weather, PID: 5754
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.weather/com.example.weather.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.preference.PreferenceManager.getDefaultSharedPreferencesName(PreferenceManager.java:555)
at android.preference.PreferenceManager.getDefaultSharedPreferences(PreferenceManager.java:545)
at com.example.weather.TinyDB.<init>(TinyDB.java:39)
at com.example.weather.MainActivity.onCreate(MainActivity.java:51)
at android.app.Activity.performCreate(Activity.java:8000)
at android.app.Activity.performCreate(Activity.java:7984)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loop(Looper.java:223) 
at android.app.ActivityThread.main(ActivityThread.java:7656) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) 
2021-09-23 13:59:38.600 5754-5754/com.example.weather I/Process: Sending signal. PID: 5754 SIG: 9

Get ratingbar value in a Toast

I appreciate your help with a problem with the ratingbar, I want to show the value of the ratingbar in a Toast when pressing a button, therefore each time you press the button, the value of the ratingbar should be displayed, however at the time pressing the button closes the application and debugging I get the following error.
"Caused by: java.lang.NullPointerException: Attempt to invoke virtual
method 'float android.widget.RatingBar.getRating()' on a null object
reference at
com.org.notas.asembisencuesta.MainActivity.onClick(MainActivity.java:114)
"
#Override
protected void onCreate(Bundle savedInstanceState) {
commentsFra = new ComentariosFragment();
navhost = new HomeFragment();
thanks = new ThanksFragment();
}
public void onClick(View view){
ratingBar = findViewById(R.id.ratingBarOne);
transaction = getSupportFragmentManager().beginTransaction();
switch (view.getId()){
case R.id.fin_encuesta: {
transaction.replace(R.id.nav_host_fragment, thanks);
transaction.addToBackStack(null);
Handler handler = new Handler();
Runnable runnable = new Runnable() {
#Override public void run() {
transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.nav_host_fragment, navhost);
transaction.addToBackStack(null); transaction.commit();
}
};
handler.postDelayed(runnable,7000);
comments = findViewById(R.id.comments_dialog);
comments.setText(""); float rating; rating = ratingBar.getRating();
//Linea 114 Toast.makeText(this, ":" + rating, Toast.LENGTH_SHORT).show();
break;
}
transaction.commit();
}
}
This is the error that it generates:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.org.notas.asembisencuesta, PID: 7682
java.lang.IllegalStateException: Could not execute method for android:onClick
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(.java:414)
at android.view.View.performClick(View.java:7146)
at android.view.View.performClickInternal(View.java:7119)
at android.view.View.access$3500(View.java:803)
at android.view.View$(View.java:27533)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7386)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:980)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(.java:409)
at android.view.View.performClick(View.java:7146)
at android.view.View.performClickInternal(View.java:7119)
at android.view.View.access$3500(View.java:803)
at android.view.View$(View.java:27533)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7386)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:980)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'float android.widget.RatingBar.getRating()' on a null object reference
at com.org.notas.asembisencuesta.MainActivity.onClick(MainActivity.java:114)
at java.lang.reflect.Method.invoke(Native Method)

Android app crashes when I run it on API 30 Android Virtual Machine

I am trying to make something that converts the text i write into EditText to speech when i press button01.
It works fine on the virtual machine with Android API 23, but it crashes and makes a NullPointerException and crashes on the virtual machine with Android API 30. Here's the code:
public MainActivity() {
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText);
button01 = (Button) findViewById(R.id.button01);
final TextView textView1 = (TextView) findViewById(R.id.text1) ;
textView1.setText("\n");
tts = new TextToSpeech(this, new TextToSpeech.OnInitListener() {
#Override
public void onInit(int status) {
if(status != ERROR) {
// 언어를 선택한다.
tts.setLanguage(Locale.ENGLISH);
} else {
textView1.setText("TTS 작업에 오류가 생기거나 지원되지 않는 언어입니다.");
tts.speak("TTS 작업에 오류가 생기거나 지원되지 않는 언어입니다.", TextToSpeech.STOPPED, null);
}
}
});
button01.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// editText에 있는 문장을 읽는다.
tts.speak(editText.getText().toString(), TextToSpeech.QUEUE_FLUSH, null);
}
});
}
#Override
protected void onDestroy() {
super.onDestroy();
// TTS 객체가 남아있다면 실행을 중지하고 메모리에서 제거한다.
if(tts != null){
tts.stop();
tts.shutdown();
tts = null;
}
}
}
When i view Logcat, it showes this:
2020-07-09 02:10:56.036 7700-7700/com.example.myapplication2 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myapplication2, PID: 7700
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myapplication2/com.example.myapplication2.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.speech.tts.TextToSpeech.speak(java.lang.String, int, java.util.HashMap)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.speech.tts.TextToSpeech.speak(java.lang.String, int, java.util.HashMap)' on a null object reference
at com.example.myapplication2.MainActivity$1.onInit(MainActivity.java:42)
at android.speech.tts.TextToSpeech.dispatchOnInit(TextToSpeech.java:836)
at android.speech.tts.TextToSpeech.initTts(TextToSpeech.java:814)
at android.speech.tts.TextToSpeech.<init>(TextToSpeech.java:745)
at android.speech.tts.TextToSpeech.<init>(TextToSpeech.java:724)
at android.speech.tts.TextToSpeech.<init>(TextToSpeech.java:708)
at com.example.myapplication2.MainActivity.onCreate(MainActivity.java:34)
at android.app.Activity.performCreate(Activity.java:7995)
at android.app.Activity.performCreate(Activity.java:7979)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loop(Looper.java:223) 
at android.app.ActivityThread.main(ActivityThread.java:7656) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) 
It's happening in the else part in onInit of your listener. When there was an error in initializing the TextToSpeech instance, onInit will be called with ERROR as input while tts is not yet initialized and is null.
It may happen when your device doesn't support text to speech or the engine is missing necessary data.
Don't call anything on tts in case of an error. (There was an error in initializing text to speech. So, how can it speak your text?!)
Apps targeting Android 11 that use text-to-speech should declare TextToSpeech.Engine.INTENT_ACTION_TTS_SERVICE in the queries elements of their manifest:
<queries>
...
<intent>
<action android:name="android.intent.action.TTS_SERVICE" />
</intent>
</queries>

Shuhart stepview null object reference

I'm using shuhart's stepview for my android application. I've followed this video. But whenever I try to enter my BookingActivity, the application crashes with the error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.estebeauty/com.example.estebeauty.activities.BookingActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.shuhart.stepview.StepView.setSteps(java.util.List)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3270)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.shuhart.stepview.StepView.setSteps(java.util.List)' on a null object reference
at com.example.estebeauty.activities.BookingActivity.setupStepView(BookingActivity.java:88)
at com.example.estebeauty.activities.BookingActivity.onCreate(BookingActivity.java:38)
at android.app.Activity.performCreate(Activity.java:7802)
at android.app.Activity.performCreate(Activity.java:7791)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016) 
at android.os.Handler.dispatchMessage(Handler.java:107) 
at android.os.Looper.loop(Looper.java:214) 
at android.app.ActivityThread.main(ActivityThread.java:7356) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 
And I don't know how to fix it.
Here is my BookingActivity:
public class BookingActivity extends AppCompatActivity {
#BindView(R.id.step_view)
StepView stepView;
#BindView(R.id.view_pager)
ViewPager viewPager;
#BindView(R.id.btn_previous_step)
Button btn_previous_step;
#BindView(R.id.btn_next_step)
Button btn_next_step;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_booking);
ButterKnife.bind(BookingActivity.this);
setupStepView();
setColorButton();
// View
viewPager.setAdapter(new MyViewPagerAdapter(getSupportFragmentManager(), 1));
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int i, float v, int i1) {
}
#Override
public void onPageSelected(int i) {
if (i == 0) {
btn_previous_step.setEnabled(false);
}
else {
btn_previous_step.setEnabled(true);
setColorButton();
}
}
#Override
public void onPageScrollStateChanged(int i) {
}
});
}
private void setColorButton() {
if (btn_next_step.isEnabled()) {
btn_next_step.setBackgroundResource(R.color.colorPrimary);
}
else {
btn_next_step.setBackgroundResource(android.R.color.darker_gray);
}
if (btn_previous_step.isEnabled()) {
btn_previous_step.setBackgroundResource(R.color.colorPrimary);
}
else {
btn_previous_step.setBackgroundResource(android.R.color.darker_gray);
}
}
private void setupStepView() { // It fails here
List<String> stepList = new ArrayList<>();
stepList.add("Treatment");
stepList.add("Date");
stepList.add("Employee");
stepList.add("Confirm");
stepView.setSteps(stepList);
}
}
I've looked at the GitHub, and can't find any related issues to this.
Please help, and thanks in advance
I managed to fix it by editing the way i was declaring my bindings. So i changed it to:
stepView = findViewById(R.id.step_view);
viewPager = findViewById(R.id.view_pager);
btn_previous_step = findViewById(R.id.btn_previous_step);
btn_next_step = findViewById(R.id.btn_next_step);

Getting Crash When trying to initiate an Activity

Almost all of the current navigation in the application is working perfectly fine and when doing the same things for other parts i navigate with.
I am getting this error when trying to navigate from one activity to another:
FATAL EXCEPTION: main
Process: com.package, PID: 15338
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.package/ui.activity.AccountActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getId()' 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 'int android.view.View.getId()' on a null object reference
at ui.activity.BaseActivity.setInitialFragment(BaseActivity.java:181)
at ui.activity.BaseActivity.setInitialFragment(BaseActivity.java:174)
at ui.activity.BaseActivity.setInitialFragment(BaseActivity.java:160)
at ui.activity.AccountActivity.setInitialFragment(AccountActivity.java:38)
at ui.activity.BaseActivity.onCreate(BaseActivity.java:56)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
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) 
I can track where the Null reference is being made and have tried a few things to try and bypass it but they all crash the application.
Here is the block where i initiate the activity:
#Override
public void onMyAccountOptionSelected() {
Intent intent = new Intent(this, AccountActivity.class);
startActivity(intent);
}
Then it gets caught here on view.getId(), this one is in baseActivity:
private void setInitialFragment(View view, Fragment fragment) {
if (this.getCurrentFragment() == null) {
FragmentManager fragmentManager = this.getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(view.getId(), fragment).commit();
}
}
I am initially calling setInitialFragment() in AccountActivity which extends my baseActivity:
#Override
protected void setInitialFragment() {
fragment = (AccountFragment) AccountFragment.newInstance();
setInitialFragment(fragment);
}
As you can see above there is now an AccountFragment, in this class i extend from an abstractFragment and have a method to declare a newInstance:
public static Fragment newInstance() {
AccountFragment fragment = new AccountFragment();
return fragment;
}
I cant find anywhere else where it may be affecting the process used for navigating to this activity. I am hoping to find a method to make a quick fix or to find a more appropriate way to solve this.
Any help is much appreciated!
You didn't provide us with all the information needed to be really helpfull.
i'm imaging that your setInitialFragment in your AccountActivity would be something like this:
public class AccountActivity extends BaseActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.container);
AccountFragment fragment = AccountFragment.getInstance();
setInitialFragment(fragment);
}
}
Based on what you posted, your are calling 2 different methods, this:
setInitialFragment(Fragment fragment);
is not the same as this
setInitialFragment(View view, Fragment fragment)

Categories

Resources