FCM (Firebase Cloud Messaging) initialize issue

I started working on FCM module, I fallowed as per the firebase guidelines. i'm getting two exceptions like RuntimeException and IllegalStateException. Firebase init default but why and what is the issue in FCM.

1. From Android Studio tools -> Firebase -> Cloud Messaging.

2. I fallowed Set up Firebase Cloud Mesasging.

I fallowed below link:

https://firebase.google.com/docs/cloud-messaging/android/client

App : Build.gradle

dependencies 
 implementation fileTree(dir: 'libs', include: ['*.jar'])
 //noinspection GradleCompatible
 implementation 'com.android.support:appcompat-v7:28.0.0'
 implementation 'com.android.support.constraint:constraint-layout:1.1.3'
 implementation 'com.google.firebase:firebase-messaging:17.4.0'
 testImplementation 'junit:junit:4.12'
 androidTestImplementation 'com.android.support.test:runner:1.0.2'
 androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'


apply plugin: 'com.google.gms.google-services'

Project : Build.gradle

buildscript 
 repositories 
 google()
 jcenter()

 
 dependencies 
 classpath 'com.android.tools.build:gradle:3.3.2'
 classpath 'com.google.gms:google-services:4.1.0'

 // NOTE: Do not place your application dependencies here; they belong
 // in the individual module build.gradle files
 


allprojects 
 repositories 
 google()
 jcenter()

 


task clean(type: Delete) 
 delete rootProject.buildDir

In MainActivity.class, i trying to get token but app crashes.

 public class MainActivity extends AppCompatActivity 

 public static final String TAG = MainActivity.class.getSimpleName();

 @Override
 protected void onCreate(Bundle savedInstanceState) 
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 String tokenId = FirebaseInstanceId.getInstance().getToken(); //Crashes in this line 
 Log.d("SH", tokenId);
 

in logcat i got two exceptions

 E/AndroidRuntime: FATAL EXCEPTION: main
 Process: com.package PID: 29368
 java.lang.RuntimeException: Unable to start activity ComponentInfocom.package.testfcm/com.package.MainActivity: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.package. Make sure to call FirebaseApp.initializeApp(Context) first.
 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2861)
 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2943)
 at android.app.ActivityThread.-wrap11(Unknown Source:0)
 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1630)
 at android.os.Handler.dispatchMessage(Handler.java:106)
 at android.os.Looper.loop(Looper.java:164)
 at android.app.ActivityThread.main(ActivityThread.java:6626)
 at java.lang.reflect.Method.invoke(Native Method)
 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)
 Caused by: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.package. Make sure to call FirebaseApp.initializeApp(Context) first.
 at com.google.firebase.FirebaseApp.getInstance(com.google.firebase:firebase-common@@16.0.2:240)
 at com.google.firebase.iid.FirebaseInstanceId.getInstance(Unknown Source:1)
 at com.package.MainActivity.onCreate(MainActivity.java:20)
 at android.app.Activity.performCreate(Activity.java:7032)
 at android.app.Activity.performCreate(Activity.java:7023)
 at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1236)
 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2814)
 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2943) 
 at android.app.ActivityThread.-wrap11(Unknown Source:0) 
 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1630) 
 at android.os.Handler.dispatchMessage(Handler.java:106) 
 at android.os.Looper.loop(Looper.java:164) 
 at android.app.ActivityThread.main(ActivityThread.java:6626) 
 at java.lang.reflect.Method.invoke(Native Method) 
 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811) 

Finally i found solutions, Now i able to get FCM Token.

In project build.gradle file you need add single line code code i.e., mavenLocal().

Fallow as per the below solutions cross check the project : build.gradle file and app : build.gradle file.

Project : build.gradle

buildscript 
 repositories 
 mavenLocal() //This is the line you need to add 
 google()
 jcenter()

 
 dependencies 
 classpath 'com.android.tools.build:gradle:3.3.2'
 classpath 'com.google.gms:google-services:4.2.0'

 // NOTE: Do not place your application dependencies here; they belong
 // in the individual module build.gradle files
 


allprojects 
 repositories 
 mavenLocal() //This is the line you need to add 
 google()
 jcenter()

 


task clean(type: Delete) 
 delete rootProject.buildDir

App : build.gradle

apply plugin: 'com.android.application'


android 
 compileSdkVersion 28
 defaultConfig 
 applicationId "com.example.testfcm"
 minSdkVersion 21
 targetSdkVersion 28
 versionCode 1
 versionName "1.0"
 testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
 
 buildTypes 
 release 
 minifyEnabled false
 proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
 
 


dependencies 
 implementation fileTree(dir: 'libs', include: ['*.jar'])
 //noinspection GradleCompatible
 implementation 'com.android.support:appcompat-v7:28.0.0'
 implementation 'com.android.support.constraint:constraint-layout:1.1.3'


 implementation 'com.google.firebase:firebase-core:16.0.8'
 implementation 'com.google.firebase:firebase-iid:17.1.1'
 implementation 'com.google.firebase:firebase-messaging:17.5.0'

 testImplementation 'junit:junit:4.12'
 androidTestImplementation 'com.android.support.test:runner:1.0.2'
 androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

apply plugin: 'com.google.gms.google-services'

Try this way.




In Android Studio GO TO TOOLS Menu.


Then Select Firebase Option.


Provide your firebase enabled google account id-password.


From right side tab select Cloud Messaging.


Then click on setup firebase messaging .


Follow mension steps over there.

I can see from your code that you are getting Firebase instance before it had to be initialized. You have to first initialize it then get token using getInstance().

FirebaseApp.initializeApp(this);

Or try the way google documents shows for getting token

FirebaseInstanceId.getInstance().getInstanceId()
 .addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() 
 @Override
 public void onComplete(@NonNull Task<InstanceIdResult> task) 
 if (!task.isSuccessful()) 
 Log.w(TAG, "getInstanceId failed", task.getException());
 return;
 

 // Get new Instance ID token
 String token = task.getResult().getToken();


 Toast.makeText(MainActivity.this, token, Toast.LENGTH_SHORT).show();
 
 );