5

Trying to set up a simple app that uses Firebase Auth to handle Registration/Login of a user. This issue is quite confusing as the outcome is different on my physical testing device (HTC M8 7.1.1) and Emulator (5P 7.1.1).

On the emulator, I get the following error when I click my Login or Register Buttons. 

                                                                --------- beginning of crash
03-02 03:24:20.625 3002-3002/com.mad.losesano E/AndroidRuntime: FATAL EXCEPTION: main
                                                                Process: com.mad.losesano, PID: 3002
                                                                java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.tasks.Task com.google.android.gms.common.api.GoogleApi.zzb(com.google.android.gms.common.api.internal.zzdd)' on a null object reference
                                                                    at com.google.android.gms.internal.zzdvv.zzb(Unknown Source)
                                                                    at com.google.android.gms.internal.zzdwc.zzb(Unknown Source)
                                                                    at com.google.firebase.auth.FirebaseAuth.signInWithEmailAndPassword(Unknown Source)
                                                                    at com.mad.losesano.LoginActivity.userLogin(LoginActivity.java:69)
                                                                    at com.mad.losesano.LoginActivity.onClick(LoginActivity.java:105)
                                                                    at android.view.View.performClick(View.java:5637)
                                                                    at android.view.View$PerformClick.run(View.java:22429)
                                                                    at android.os.Handler.handleCallback(Handler.java:751)
                                                                    at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                    at android.os.Looper.loop(Looper.java:154)
                                                                    at android.app.ActivityThread.main(ActivityThread.java:6119)
                                                                    at java.lang.reflect.Method.invoke(Native Method)
                                                                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

On my physical device, when I register a user, it works as expected. The user account can be seen in the firebase console. When I click 'login' on the this device, nothing happens. It seems that it doesn't even enter the OnClick method (tested by running a Log.d message in the OnClick method which doesn't show up when I click the button).

Here is the LoginActivity Code

package com.mad.losesano;

        import android.app.Activity;
        import android.content.Intent;
        import android.support.annotation.NonNull;
        import android.os.Bundle;
        import android.util.Log;
        import android.util.Patterns;
        import android.view.View;
        import android.widget.Button;
        import android.widget.EditText;
        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 LoginActivity extends Activity implements View.OnClickListener {

    FirebaseAuth mAuth;
    EditText et_email, et_password;
    Button login_button;

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

        mAuth = FirebaseAuth.getInstance();

        et_email = (EditText) findViewById(R.id.email_et_login);
        et_password = (EditText) findViewById(R.id.password_et_login);

        findViewById(R.id.register_tv).setOnClickListener(this);
        login_button = (Button) findViewById(R.id.login_button);
        login_button.setOnClickListener(this);

    }

    private void userLogin() {
        String email = et_email.getText().toString().trim();
        String password = et_password.getText().toString().trim();

        if (email.isEmpty()) {
            et_email.setError("Email is required");
            et_email.requestFocus();
            return;
        }

        if (!Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            et_email.setError("Please enter a valid email");
            et_email.requestFocus();
            return;
        }

        if (password.isEmpty()) {
            et_password.setError("Password is required");
            et_password.requestFocus();
            return;
        }

        if (password.length() < 6) {
            et_password.setError("Minimum lenght of password should be 6");
            et_password.requestFocus();
            return;
        }

        mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(LoginActivity.this, new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {
                if (task.isSuccessful()) {
                    finish();
                    Intent intent = new Intent(LoginActivity.this, LoggedInActivity.class);
                    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(intent);
                } else {
                    Toast.makeText(getApplicationContext(), task.getException().getMessage(), Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    @Override
    protected void onStart() {
        super.onStart();

        if (mAuth.getCurrentUser() != null) {
            finish();
            startActivity(new Intent(this, LoggedInActivity.class));
        }
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.register_tv:
                finish();
                Log.d("LoSeSANO", "Register Button Clicked");
                startActivity(new Intent(LoginActivity.this, SignupActivity.class));
                break;

            case R.id.login_button:
                Log.d("LoSeSANO", "Login Button Clicked");
                userLogin();
                break;
        }
    }
}

Here is the SignupActivity code

package com.mad.losesano;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.util.Log;
import android.util.Patterns;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
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;
import com.google.firebase.auth.FirebaseAuthUserCollisionException;

/**
 * Created by oshau on 01/03/2018.
 */

public class SignupActivity extends Activity implements View.OnClickListener {

    EditText et_email, et_password;
    Button register_button;
    private FirebaseAuth mAuth;

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

        et_email = (EditText) findViewById(R.id.email_et_login);
        et_password = (EditText) findViewById(R.id.password_et_login);

        mAuth = FirebaseAuth.getInstance();

        register_button = (Button) findViewById(R.id.register_button);
        register_button.setOnClickListener(this);
        findViewById(R.id.login_tv).setOnClickListener(this);

    }

    private void registerUser() {
        Log.d("LoSeSANO", "Email Address: " + et_email.getText().toString());
        String email = et_email.getText().toString().trim();
        String password = et_password.getText().toString().trim();

        if (email.isEmpty()) {
            et_email.setError("Email is required");
            et_email.requestFocus();
            return;
        }

        if (!Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            et_email.setError("Please enter a valid email");
            et_email.requestFocus();
            return;
        }

        if (password.isEmpty()) {
            et_password.setError("Password is required");
            et_password.requestFocus();
            return;
        }

        if (password.length() < 6) {
            et_password.setError("Minimum lenght of password should be 6");
            et_password.requestFocus();
            return;
        }

        mAuth.createUserWithEmailAndPassword(email, password).addOnCompleteListener(SignupActivity.this, new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {
                if (task.isSuccessful()) {
                    finish();
                    startActivity(new Intent(SignupActivity.this, LoginActivity.class));
                } else {

                    if (task.getException() instanceof FirebaseAuthUserCollisionException) {
                        Toast.makeText(getApplicationContext(), "You are already registered", Toast.LENGTH_SHORT).show();

                    } else {
                        Toast.makeText(getApplicationContext(), task.getException().getMessage(), Toast.LENGTH_SHORT).show();
                    }

                }
            }
        });

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.register_button:
                registerUser();
                break;

            case R.id.login_tv:
                finish();
                startActivity(new Intent(SignupActivity.this, LoginActivity.class));
                break;
        }
    }
}

Here is my login_activity.xml and signup_activity.xml if needed

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:id="@+id/welcome_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:fontFamily="sans-serif-light"
        android:text="@string/welcome_string"
        android:textColor="#f0eeec"
        android:textSize="40dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:layout_editor_absoluteY="80dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="202dp"
        android:layout_height="62dp"
        android:layout_marginTop="8dp"
        android:fontFamily="sans-serif-light"
        android:gravity="center"
        android:text="@string/sub_welcome_string"
        android:textColor="#f0eeec"
        android:textSize="14dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/welcome_tv" />

    <EditText
        android:id="@+id/email_et_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:backgroundTint="@android:color/holo_green_light"
        android:ems="10"
        android:fontFamily="sans-serif-light"
        android:inputType="textPersonName"
        android:text="@string/register_et_string"
        android:textColor="#f0eeec"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <EditText
        android:id="@+id/password_et_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:backgroundTint="@android:color/holo_green_light"
        android:ems="10"
        android:fontFamily="sans-serif-light"
        android:hint="Password"
        android:inputType="textPassword"
        android:text="Password"
        android:textColor="#f0eeec"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/email_et_login" />

    <Button
        android:id="@+id/login_button"
        android:layout_width="151dp"
        android:layout_height="55dp"
        android:layout_marginTop="16dp"
        android:backgroundTint="#6c8c0e"
        android:fontFamily="sans-serif-light"
        android:text="@string/login_register_button_string"
        android:textColor="#f0eeec"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/password_et_login" />

    <TextView
        android:id="@+id/register_tv"
        android:layout_width="wrap_content"
        android:layout_height="22dp"
        android:layout_marginTop="8dp"
        android:backgroundTint="#6c8c0e"
        android:fontFamily="sans-serif-light"
        android:text="@string/register_tv_string"
        android:textColor="#f0eeec"
        android:textSize="16dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/login_button" />

    <TextView
        android:id="@+id/password_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:backgroundTint="#6c8c0e"
        android:fontFamily="sans-serif-light"
        android:text="@string/forgot_password_tv_string"
        android:textColor="#f0eeec"
        android:textSize="16dp"
        app:layout_constraintHorizontal_bias="0.501"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/register_tv" />

</android.support.constraint.ConstraintLayout>

signup_activity

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:id="@+id/welcome_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:fontFamily="sans-serif-light"
        android:text="@string/welcome_string"
        android:textColor="#f0eeec"
        android:textSize="40dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:layout_editor_absoluteY="80dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="202dp"
        android:layout_height="62dp"
        android:layout_marginTop="8dp"
        android:fontFamily="sans-serif-light"
        android:gravity="center"
        android:text="@string/sub_welcome_string"
        android:textColor="#f0eeec"
        android:textSize="14dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/welcome_tv" />

    <EditText
        android:id="@+id/email_et_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:backgroundTint="@android:color/holo_green_light"
        android:ems="10"
        android:fontFamily="sans-serif-light"
        android:inputType="textPersonName"
        android:text="@string/register_et_string"
        android:textColor="#f0eeec"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <EditText
        android:id="@+id/password_et_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:backgroundTint="@android:color/holo_green_light"
        android:ems="10"
        android:fontFamily="sans-serif-light"
        android:hint="Password"
        android:inputType="textPassword"
        android:text="Password"
        android:textColor="#f0eeec"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/email_et_login" />

    <Button
        android:id="@+id/register_button"
        android:layout_width="151dp"
        android:layout_height="55dp"
        android:layout_marginTop="16dp"
        android:backgroundTint="#6c8c0e"
        android:fontFamily="sans-serif-light"
        android:text="@string/register_tv_string"
        android:textColor="#f0eeec"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/password_et_login" />

    <TextView
        android:id="@+id/login_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="12dp"
        android:backgroundTint="#6c8c0e"
        android:fontFamily="sans-serif-light"
        android:text="@string/login_register_button_string"
        android:textColor="#f0eeec"
        android:textSize="16dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/register_button" />

</android.support.constraint.ConstraintLayout>

Any help would be greatly appreciated!

Doug Stevenson
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Shox2711
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  • Does the emulator have Play Services on it? – Doug Stevenson Mar 03 '18 at 02:13
  • See this answer to related question: https://stackoverflow.com/a/48975027/4815718 – Bob Snyder Mar 03 '18 at 02:19
  • Woops. Silly oversight on my part. Updated GPS and it's no longer crashing. However, nothing is still happening when I click on 'Login' (It should open LoggedInActivity). Probably something silly. Thanks so much for the help! – Shox2711 Mar 03 '18 at 02:45
  • Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) – Abu Yousuf Mar 03 '18 at 03:47
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    @AbuYousuf Just because the question contains the word `NullPointerException` does not mean it is a duplicate of someone asking what a NPE is. Nowhere in this question is he asking about what an NPE is, but why he is getting it when to his knowledge he has everything filled out correctly. Not all NPE is a result of someone's incorrect coding (as his comment shows that it had to do with not having the correct version of GPS) – Jon Tinsman Mar 27 '18 at 04:38

3 Answers3

0

I researched this issue and I found that error appear when phone doesn't have any google account.

Vaclovas Rekašius Jr.
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0

I had exactly the same issue (also using firebase), and solved it by installing gapps with genymotion.

Stephen Rauch
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Agung Cahyo Nugroho
  • 1
0

Here is Bob Snyder's solution: Android Firebase Auth Crash on KitKat

Based on his answer I made this in the starter activity's onCreate() method:

if (GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(this) == ConnectionResult.SUCCESS) {
    // OK, you can do your job
}

There can be other results which you should also handle: SERVICE_MISSING, SERVICE_UPDATING, SERVICE_VERSION_UPDATE_REQUIRED, SERVICE_DISABLED, SERVICE_INVALID

gabhor
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