I'm having difficulty understanding something with my app.
I am using Firebase to provide user authentication which works fine until I try it on other phones/devices.
When I put in the email and password and press 'Login', the app crashes and the log gives the following:
FATAL EXCEPTION: main Process: com.example.android.frapp, PID: 14822
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.zzdf)' on a null object reference
at com.google.android.gms.internal.zzdtp.zzb(Unknown Source)
at com.google.android.gms.internal.zzdtw.zzb(Unknown Source)
at com.google.firebase.auth.FirebaseAuth.signInWithEmailAndPassword(Unknown Source)
at com.example.android.frapp.MainLoginActivity.startSiginIn(MainLoginActivity.java:105)
at com.example.android.frapp.MainLoginActivity.access$000(MainLoginActivity.java:23)
at com.example.android.frapp.MainLoginActivity$2.onClick(MainLoginActivity.java:65)
at android.view.View.performClick(View.java:5197)
at android.view.View$PerformClick.run(View.java:20926)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5951)
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:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
It's all happening from my main login class (which I have provided below):
public class MainLoginActivity extends AppCompatActivity {
private EditText mEmailField;
private EditText mPasswordField;
private Button mLoginBtn;
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
private boolean isUserClickedBackButton = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_login);
mAuth = FirebaseAuth.getInstance();
mEmailField = (EditText) findViewById(R.id.emailField);
mPasswordField = (EditText) findViewById(R.id.passwordField);
mLoginBtn = (Button) findViewById(R.id.loginBtn);
// connection to user authentication on firebase (database)
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
if (firebaseAuth.getCurrentUser() != null){
startActivity(new Intent(MainLoginActivity.this, MainActivity.class));
}
}
};
mLoginBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
startSiginIn();
}
});
}
@Override
protected void onStart() {
super.onStart();
mAuth.addAuthStateListener(mAuthListener);
}
@Override
// code for exiting from app by using back button on login page
public void onBackPressed() {
//moveTaskToBack(true);
if (!isUserClickedBackButton){
Toast.makeText(this, "Press back again to exit", Toast.LENGTH_SHORT).show();
isUserClickedBackButton = true;
} else {
System.exit(0); // exits right out of app
super.onBackPressed();
}
}
// for login
private void startSiginIn() {
String email = mEmailField.getText().toString();
String password = mPasswordField.getText().toString();
if (TextUtils.isEmpty(email) || TextUtils.isEmpty(password)) {
Toast.makeText(MainLoginActivity.this, "Please input email and password", Toast.LENGTH_LONG).show();
} else {
mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (!task.isSuccessful())
Toast.makeText(MainLoginActivity.this, "Sign in problem. Please check email" +
" and password", Toast.LENGTH_LONG).show();
}
});
}
}
}
As I say, it works perfect on my main device but doesn't when I install and try to login on other devices. And it also works fine on the emulator.
I've tried searching for similar problems but can't find any.
Has anyone got any ideas?
Thanks
