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Default FirebaseApp is not initialized android studio

When I run the app I get an error while launching the app. It shows me that I forgot to do something with FireBase and it shows me this as well: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.t.androiduberremake. Make sure to call FirebaseApp.initializeApp(Context) first.
there's my code
private final static int LOGIN_REQUEST_CODE =7171;
private List<AuthUI.IdpConfig> providers;
private FirebaseAuth firebaseAuth;
private FirebaseAuth.AuthStateListener listener;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FirebaseApp.initializeApp(this);
init();
}
private void init() {
providers = Arrays.asList(
new AuthUI.IdpConfig.PhoneBuilder().build(),
new AuthUI.IdpConfig.GoogleBuilder().build());
firebaseAuth =FirebaseAuth.getInstance();
listener = myFirebaseAuth ->{
FirebaseUser user = myFirebaseAuth.getCurrentUser();
if(user != null)
delaySplashScreen();
else
showLoginLayout();
};
}
private void showLoginLayout() {
AuthMethodPickerLayout authMethodPickerLayout = new AuthMethodPickerLayout
.Builder(R.layout.layout_sign_in).setPhoneButtonId(R.id.btn_phone_sign_in)
.setGoogleButtonId(R.id.btn_google_sign_in).build() ;
startActivityForResult(AuthUI.getInstance()
.createSignInIntentBuilder()
.setAuthMethodPickerLayout(authMethodPickerLayout)
.setIsSmartLockEnabled(false).setAvailableProviders(providers)
.build(), LOGIN_REQUEST_CODE);
}
private void delaySplashScreen() {
Completable.timer(5, TimeUnit.SECONDS, AndroidSchedulers.mainThread())
.subscribe(() -> Toast.makeText(SplashScreenActivity.this, "Splash Screen done!! ", Toast.LENGTH_SHORT).show());
}
#Override
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == LOGIN_REQUEST_CODE){
IdpResponse response = IdpResponse.fromResultIntent(data);
if(resultCode == RESULT_OK){
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
}
else {
Toast.makeText(this, "[ERROR]: "+ response.getError().getMessage(), Toast.LENGTH_SHORT).show();
}
}
}
that is what console shows me when I try to run a given app:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.t.androiduberremake/com.t.androiduberremake.SplashScreenActivity}: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.t.androiduberremake. Make sure to call FirebaseApp.initializeApp(Context) first.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3760)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3939)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2373)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:8147)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1101)
Caused by: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.t.androiduberremake. Make sure to call FirebaseApp.initializeApp(Context) first.
at com.google.firebase.FirebaseApp.getInstance(com.google.firebase:firebase-common##19.3.0:184)
at com.google.firebase.auth.FirebaseAuth.getInstance(com.google.firebase:firebase-auth##19.3.2:1)
at com.t.androiduberremake.SplashScreenActivity.init(SplashScreenActivity.java:49)
at com.t.androiduberremake.SplashScreenActivity.onCreate(SplashScreenActivity.java:39)
at android.app.Activity.performCreate(Activity.java:8066)
at android.app.Activity.performCreate(Activity.java:8054)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1313)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3733)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3939) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2373) 
at android.os.Handler.dispatchMessage(Handler.java:107) 
at android.os.Looper.loop(Looper.java:213) 
at android.app.ActivityThread.main(ActivityThread.java:8147) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1101) 
2020-08-13 15:33:55.746 12265-12265/? I/Process: Sending signal. PID: 12265 SIG: 9

You haven't added the google-services plugin to your build.gradle. Its important.
According to the documentation, you also have to add:
apply plugin: 'com.google.gms.google-services'

How to move reusable functionalities to a generic class and invoke another activity from there?

I am new to Android development and I am facing an issue in invoking an activity from a generic class where I have a reusable function.
I have MainActivity where I need to check if the application has Network connectivity and then check if the user is already signed in.
If the user is signed in I need to open the Rate activity otherwise I will open the Login activity.
I thought I can keep the logic that checks the Network connectivity and shows the popup reusable and move it to a Global class as below
public class Global extends AppCompatActivity {
public static boolean hasConnectivity = false;
public static boolean userSignedIn = false;
String TAG = "Debug Log - Helper";
Context context;
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
context = this;
}
private void networkConnectionErrorDialog(final Context context, final Class targetClass){
Log.d(TAG, "Show Alert Dialog");
new AlertDialog.Builder(context)
.setTitle(R.string.connection_error_title)
.setMessage(R.string.connection_error_message)
.setIcon(R.drawable.warning)
.setPositiveButton(
R.string.try_again,
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Log.d(TAG, "Trying Again");
isNetworkAvailable(context, targetClass);
}
}).show();
}
protected void isNetworkAvailable(Context context, Class targetClass) {
if(NetworkUtil.isConnected(context)){
Log.d(TAG, "Has connectivity");
if(targetClass != null){
Log.d(TAG, targetClass.toString());
Intent targetIntent = new Intent(context, targetClass);
startActivity(targetIntent);
}
hasConnectivity = true;
return;
}else{
Log.d(TAG, "Has no connectivity");
hasConnectivity = false;
networkConnectionErrorDialog(context, targetClass);
}
}
}
I pass in the targetClass as Login.class or Rate.class (based on user signed in state) from the MainActivity where isNetworkAvailable() is invoked.
I am getting the following error. Could someone help me fix the issue and help me understand if my approach needs improvement?
java.lang.RuntimeException: Unable to resume activity {com.solitontech.dayatsoliton/com.solitontech.dayatsoliton.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.app.ActivityThread$ApplicationThread android.app.ActivityThread.getApplicationThread()' on a null object reference
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3581)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3621)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2862)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.app.ActivityThread$ApplicationThread android.app.ActivityThread.getApplicationThread()' on a null object reference
at android.app.Activity.startActivityForResult(Activity.java:4488)
at android.support.v4.app.BaseFragmentActivityJB.startActivityForResult(BaseFragmentActivityJB.java:50)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:79)
at android.app.Activity.startActivityForResult(Activity.java:4445)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:859)
at android.app.Activity.startActivity(Activity.java:4806)
at android.app.Activity.startActivity(Activity.java:4774)
at com.solitontech.dayatsoliton.Global.isNetworkAvailable(Global.java:50)
at com.solitontech.dayatsoliton.MainActivity.onResume(MainActivity.java:68)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1355)
at android.app.Activity.performResume(Activity.java:7117)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3556)

It looks like your application is experiencing a null pointer exception in your activity's onResume method. If you had called startActivityForResult, make sure that the data in
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{..}
is non null before processing it.
As for your question about starting an activity from your helper class Global, you can define a function like this.
private static void goToActivity(Context context, Class<?> activityClass){
Intent intent = new Intent(context, activityClass);
context.startActivity(intent);
}
You can call this method as below.
goToActivity(context,TargetActivity.class);
Good luck.

Intent targetIntent = new Intent(context, targetClass);
startActivity(targetIntent);
above code is wrong. You should pass your current activity and target activity here.
Intent intent = new Intent(CurrentActivity.this, TargetingActivity.class);
startActivity(intent);
As a example :
If you want to start ActivtyB form ActivtyA
Intent intent = new Intent(ActivityA.this, ActivityD.class);
startActivity(intent);
1st try to correct this error. then you can find some others.

Null Error attempting to create an intent in AsyncTask

Apologizes if this is a stupid question but I'm attempting to create a Intent to the next activity in AsynTask after it has pulled a user from my AWS Database. Note that this class is HomeActivity and the next one is GroupActivity. Below I have the button that will run the AsynTask:
Button groupPageBtm = findViewById(R.id.groupPage);
groupPageBtm.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
LoadGroupUser loadGroupUser = new LoadGroupUser(HomeActivity.this);
loadGroupUser.execute(makeUserIDString.uniqueIDCreater(userProfile));
}
});
Here is my AsynTask subclass:
class LoadGroupUser extends AsyncTask<String, Void, GroupDO>{
private DynamoDBMapper dynamoDBMapper;
Activity activity;
public LoadGroupUser(Activity mActivity){
this.activity = mActivity;
}
Intent groupLoadIntent = new Intent(activity, GroupActivity.class);
#Override
protected GroupDO doInBackground(String... groupPresidentGroups) {
AmazonDynamoDBClient dynamoDBClient = new AmazonDynamoDBClient(AWSMobileClient.getInstance().getCredentialsProvider());
this.dynamoDBMapper = DynamoDBMapper.builder()
.dynamoDBClient(dynamoDBClient)
.awsConfiguration(AWSMobileClient.getInstance().getConfiguration())
.build();
GroupDO groupPresDO = dynamoDBMapper.load(GroupDO.class, groupPresidentGroups[0]);
Log.i("loadedPresident: ", groupPresDO.getGroupId().toString());
return null;
}
#Override
protected void onPostExecute(GroupDO groupDO) {
super.onPostExecute(groupDO);
groupLoadIntent.putExtra("groupPresident", groupDO.getGroupPresident().toString());
activity.startActivity(groupLoadIntent);
Log.i("groupPresident", groupDO.getGroupPresident().toString());
}
}
Error Message:
-12 17:02:59.424 10503-10503/com.ronone.securesender E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.ronone.securesender, PID: 10503
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ComponentName.<init>(ComponentName.java:130)
at android.content.Intent.<init>(Intent.java:5780)
at com.ronone.securesender.LoadGroupUser.<init>(HomeActivity.java:188)
at com.ronone.securesender.HomeActivity$1.onClick(HomeActivity.java:77)
at android.view.View.performClick(View.java:6294)
at android.view.View$PerformClick.run(View.java:24770)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

The problem is here:
public LoadGroupUser(Activity mActivity){
this.activity = mActivity;
}
Intent groupLoadIntent = new Intent(activity, GroupActivity.class);
The field initializer runs before the constructor, so activity is still null. Do this instead:
Intent groupLoadIntent;
public LoadGroupUser(Activity mActivity){
this.activity = mActivity;
groupLoadIntent = new Intent(activity, GroupActivity.class);
}
But note that you're potentially leaking your activity by having a strong reference to it in an AsyncTask. That's a whole other topic. Search this site for "AsyncTask activity leak."

Context for intent in onpostexecute is not null but getting null exception

I've been stumped with this problem for two days now. I've checked this forum and other forums but can't get a question or answer close enough to my problem.
Basically I'm trying to execute an intent to open an activity from a non-activities onpostexecute, I'm sending the context (MainActivty.this) and string from a onMarkerClick function that is in a method in the MainActivity. This is going to a constructor in the non-activity which has the parameters for context and the string.
The issue is that I'm getting a null exception, but after debugging, the context is not null, it has the value of MainActivity, but when the intent is executed it returns a null exception. I've also tried many variations eg. Activity, getApplicationContext, this.context, (classname).context, (classname).this and tried a global context to no avail. The odd thing is I put the intent into an if statement if(context != null) and it passes through and it executes the intent which in turn gives me null exception which doesn't make sense. I know I'm new to android if anyone has any other suggestions on opening the activity that would be great thanks very much.
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.quantusapps.joggertest, PID: 12253
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ContextWrapper.getPackageName(ContextWrapper.java:131)
at android.content.ComponentName.(ComponentName.java:77)
at android.content.Intent.(Intent.java:4029)
at com.example.quantusapps.joggertest.BusCoachTramInfo.onPostExecute(BusCoachTramInfo.java:131)
at com.example.quantusapps.joggertest.BusCoachTramInfo.onPostExecute(BusCoachTramInfo.java:25)
at android.os.AsyncTask.finish(AsyncTask.java:632)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:155)
at android.app.ActivityThread.main(ActivityThread.java:5696)
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:1028)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)<
This is the Mainactivity Method with onMarkerClick
mGoogleMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
#Override
public boolean onMarkerClick(Marker marker) {
String bctID = bctExtraMarkerInfo.get(marker.getId());
BusCoachTramInfo busCoachTramInfo = new BusCoachTramInfo(bctID, MainActivity.this);
busCoachTramInfo.execute(bctID);
return false;
}
});
This is the non-activity constructor.
Context context;
BusCoachTramInfo(String busstopID, Context context) {
this.context = context;
naptanIdUrl = "https://api.tfl.gov.uk/StopPoint/" + busstopID + "/Arrivals?app_key=" + tfl_API_KEY + "&app_id=9c0b3009";
}
This is where the null exception is happening.
#Override
protected void onPostExecute(TreeMap<Integer, String[]> Map) {
super.onPostExecute(Map);
Intent i = new Intent(context, BusArrivalTime.class);
context.startActivity(i);

One way to get things done is implementing the AsyncTask as part of a method which takes an instance of MainActivity as a parameter. The AsyncTask on the other hand would work with a WeakReference:
void doExecuteBusCoachTramInfo(final String busstopID, MainActivity activity){
final WeakReference<MainActivity> wrActivity = new WeakReference<MainActivity>(MainActivity.this);
new AsyncTask<Void, Void, TreeMap<Integer, String[]>>(){
#Override
protected TreeMap<Integer, String[]> doInBackground(Void... params)
{
// your code from BusCoachTramInfo here
}
#Override
protected void onPostExecute(TreeMap<Integer, String[]> integerTreeMap)
{
// get back to the original Activity if possible:
MainActivity activity = wrActivity.get();
if (activity != null){
Intent i = new Intent(activity, BusArrivalTime.class);
activity.startActivity(i);
}
}
}.execute();
}
This method may be part of MainActivity, but it can just as well belong to some other class.

Android: java.lang.IllegalStateException: Already attached

I'm developing an Android app to store personal info in SQLite database, withdraw them out and display the list in Activity.Actually,the moment users have put data into database and returned to Activity,the page must be refreshed to upgrade the list with something new data.I used the statementonCreate(null) to make it,but an exception came into being:java.lang.IllegalStateException: Already attached.
Here is the code :
/* MainActivity */
public class MainActivity
extends AppCompatActivity
implements View.OnClickListener{
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode==0x1&&resultCode==RESULT_OK){
onCreate(null); // Upgrade the list
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button addItem=(Button)findViewById(R.id.addItem);
addItem.setOnClickListener(this);
.....
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.addItem:
Intent intent=new Intent(this,AddItemActivity.class);
startActivityForResult(intent,0x1);
break;
default:
break;
}
}
}
/*AddItemActivity*/
public class AddItemActivity
extends AppCompatActivity
implements View.OnClickListener{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_item);
Button submit=(Button)findViewById(R.id.submit);//get submit button
submit.setOnClickListener(this);
....
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.submit:
EditText editName=(EditText)findViewById(R.id.editName),
editAge=(EditText)findViewById(R.id.editAge);
insert(new Person(
editName.getText().toString(),
Integer.parseInt(editAge.getText().toString())));
//return
setResult(RESULT_OK,null);
finish();
break;
default:
break;
}
}
}
stackTrace is this:
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=null} to activity {com.example.sqlitetest/com.example.sqlitetest.MainActivity}: java.lang.IllegalStateException: Already attached
at android.app.ActivityThread.deliverResults(ActivityThread.java:4053)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:4096)
at android.app.ActivityThread.-wrap20(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1516)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.IllegalStateException: Already attached
at android.support.v4.app.FragmentManagerImpl.attachController(FragmentManager.java:2871)
at android.support.v4.app.FragmentController.attachHost(FragmentController.java:104)
at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:317)
at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:85)
at com.example.sqlitetest.MainActivity.onCreate(MainActivity.java:29)
at com.example.sqlitetest.MainActivity.onActivityResult(MainActivity.java:23)
at android.app.Activity.dispatchActivityResult(Activity.java:6915)