添加 FirebaseAuth.getInstance 后应用崩溃

Question

I had added firebase authentication yesterday and it was working fine but today after editing some files it is crashing. App only crashes when I add "firebaseAuth =FirebaseAuth.getInstance()". If I remove it then all things work fine but now I cannot add firebase.

SignUp.java

import android.app.ProgressDialog;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

public class SignUp extends AppCompatActivity implements View.OnClickListener {

    private TextView alreadyRegistered;
    private EditText mEmailView;
    private EditText mPasswordView;
    private Button signup;
    private FirebaseAuth firebaseAuth;
    ProgressDialog progressDialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sign_up);

        progressDialog=new ProgressDialog(this);

        mEmailView =  (EditText) findViewById(R.id.email_signup);

        mPasswordView = (EditText) findViewById(R.id.password_signup);

        signup=(Button)findViewById(R.id.signup);

        alreadyRegistered=(TextView)findViewById(R.id.already_registered);

//        firebaseAuth =FirebaseAuth.getInstance();
////        if(firebaseAuth.getCurrentUser() != null){
////            //that means user is already logged in
////            //so close this activity
////            finish();
////
////            //and open profile activity
////            startActivity(new Intent(getApplicationContext(), Home.class));
////        }

        alreadyRegistered.setOnClickListener(this);
        signup.setOnClickListener(this);

    }
    private void registerUser() {

        //getting email and password from edit texts
        String email = mEmailView.getText().toString().trim();
        String password = mPasswordView.getText().toString().trim();

        //checking if email and passwords are empty
        if (TextUtils.isEmpty(email)) {
            Toast.makeText(this, "Please enter email", Toast.LENGTH_LONG).show();
            return;
        }

        if (TextUtils.isEmpty(password)) {
            Toast.makeText(this, "Please enter password", Toast.LENGTH_LONG).show();
            return;
        }


        //if the email and password are not empty
        //displaying a progress dialog

        progressDialog.setMessage("Registering Please Wait...");
        progressDialog.show();

        //creating a new user
        firebaseAuth.createUserWithEmailAndPassword(email, password)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        //checking if success
                        if (task.isSuccessful()) {
                            //display some message here
                            Toast.makeText(SignUp.this, "Successfully registered", Toast.LENGTH_LONG).show();
                            Intent intent = new Intent(SignUp.this, MainActivity.class);
                            startActivity(intent);
                        } else {
                            //display some message here
                            Toast.makeText(SignUp.this, "Registration Error", Toast.LENGTH_LONG).show();
                        }
//                        progressDialog.dismiss();
                    }
                });
    }

    @Override
    public void onClick(View v) {

        if(v==signup)
        {
            registerUser();
        }
        if(v==alreadyRegistered)
        {
            Intent intent = new Intent(SignUp.this,MainActivity.class);
            startActivity(intent);
        }
    }
}

I tried debugging and it crashes when I run that particular line.

Crash Logs

2019-02-16 14:43:23.569 25053-25053/com.example.android.nirog E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.android.nirog, PID: 25053
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.nirog/com.example.android.nirog.SignUp}: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.example.android.nirog. Make sure to call FirebaseApp.initializeApp(Context) first.
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2949)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3027)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1745)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:200)
        at android.app.ActivityThread.main(ActivityThread.java:6956)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:519)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:836)
     Caused by: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.example.android.nirog. 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.auth.FirebaseAuth.getInstance(Unknown Source:1)
        at com.example.android.nirog.SignUp.onCreate(SignUp.java:44)
        at android.app.Activity.performCreate(Activity.java:7225)
        at android.app.Activity.performCreate(Activity.java:7216)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2902)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3027) 
        at android.app.ActivityThread.-wrap11(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1745) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:200) 
        at android.app.ActivityThread.main(ActivityThread.java:6956) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:519) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:836) 
2019-02-16 14:43:23.623 25053-25053/com.example.android.nirog I/Process: Sending signal. PID: 25053 SIG: 9

Answer 1

You have not initialised firebase. Add this in onCreate of your SignUp class

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sign_up);
         FirebaseApp.initializeApp(Context)

Answer 2

This is most helpful in android with fluuter and firebase

in app level build.gradle

 defaultConfig {      

    minSdkVersion 23

}

in project level gradle.properties add

org.gradle.jvmargs=-Xmx1536M
android.useAndroidX=true
android.enableJetifier=true
android.enableR8=true

in build.gradle add

dependencies {
    classpath 'com.android.tools.build:gradle:3.4.2'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    classpath 'com.google.gms:google-services:4.2.0'
}

you can skip that Kotlin plugin if you are not using Kotlin support Dont forget to run flutter clean and then flutter pub upgrade

These changes helped me preventing my app crashes, It should help you too.

Answer 3

Make sure to call FirebaseApp.initializeApp(Context) first in Android method added in MyApplication class in your project like:

override fun onCreate() {
        super.onCreate()
{
FirebaseApp.initializeApp(Context);

}