How to make a user sign out in Firebase?

Question

I am making a simple authentication app in Android using Firebase authentication. Till now I am successful in signing the user in, however the issue is that the user remains signed in, and I can't find a way to sign him out.

Here is my MainActivity.java code

public class MainActivity extends AppCompatActivity {

    private FirebaseAuth mAuth;
    private FirebaseAuth.AuthStateListener mAuthListener;

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

        //tracking the sign in and singn out operations
        mAuth = FirebaseAuth.getInstance();
        mAuthListener = new FirebaseAuth.AuthStateListener(){
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                FirebaseUser user = firebaseAuth.getCurrentUser();
                if (user!=null){
                    System.out.println("User logged in");
                }
                else{
                    System.out.println("User not logged in");
                }
            }
        };
    }


    public void onStart(){
        super.onStart();
        mAuth.addAuthStateListener(mAuthListener);
    }
    public void onStop(){
        super.onStop();
        if (mAuthListener != null) {
            mAuth.removeAuthStateListener(mAuthListener);

        }
    }


    public void buttonClicked(View view){

        EditText editemail = (EditText) findViewById(R.id.email);
        EditText editpass = (EditText) findViewById(R.id.password);

        String email = editemail.getText().toString();
        String password = editpass.getText().toString();


        mAuth.signInWithEmailAndPassword(email, password)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                     //   Log.d(TAG, "signInWithEmail:onComplete:" + task.isSuccessful());
                        Toast.makeText(MainActivity.this, "Authentication Success.",
                                Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(MainActivity.this,Success.class));
                        // If sign in fails, display a message to the user. If sign in succeeds
                        // the auth state listener will be notified and logic to handle the
                        // signed in user can be handled in the listener.
                        if (!task.isSuccessful()) {
                           // Log.w(TAG, "signInWithEmail", task.getException());
                            Toast.makeText(MainActivity.this, "Authentication failed.",
                                    Toast.LENGTH_SHORT).show();
                        }

                        // ...
                    }
                });
    }



}

Solution 1

Use this code FirebaseAuth.getInstance().signOut();

Solution 2

You can simply call this

FirebaseAuth.getInstance().signOut();

If you want to perform some action after sign out then use this one.

public void onClick(View v) {
    if (v.getId() == R.id.sign_out) {
        AuthUI.getInstance()
            .signOut(this)
            .addOnCompleteListener(new OnCompleteListener<Void>() {
                public void onComplete(@NonNull Task<Void> task) {
                    // user is now signed out
                    startActivity(new Intent(MyActivity.this, SignInActivity.class));
                    finish();
                }
            });
        }
    }

Solution 3

This can be solved by using AuthStateListener

//Declaration and defination
private FirebaseAuth firebaseAuth;
FirebaseAuth.AuthStateListener authStateListener = new FirebaseAuth.AuthStateListener() {
    @Override
    public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
        if (firebaseAuth.getCurrentUser() == null){
            //Do anything here which needs to be done after signout is complete
            signOutComplete();
        }
        else {
        }
    }
};

//Init and attach
firebaseAuth = FirebaseAuth.getInstance();
firebaseAuth.addAuthStateListener(authStateListener);

//Call signOut()
firebaseAuth.signOut();

Snippet : https://codepad.co/snippet/aPeehdoD

Solution 4

Firebase auth is provide signout method.

 FirebaseAuth.getInstance().signOut();

Solution 5

Try This

FirebaseAuth fAuth = FirebaseAuth.getInstance();
 fAuth.signOut();

View more solutions

Comments

[Suzan Cruz]

Thanks, it worked, I put this code FirebaseAuth.getInstance().signOut();" in my onStop method. Hopefully thats the correct way td do so.

[Suzan Cruz]

Thanks, it worked, I put this code FirebaseAuth.getInstance().signOut();" in my onStop method. Hopefully thats the correct way td do so.

[Ojonugwa Jude Ochalifu]

unless you need fAuth for something else, FirebaseAuth.getInstance().signOut(); works just fine

[Mr. Mad]

# Khyati Fataniai don't think that you ever tried the above code mentioned in my reply. otherwise you will not say like this . i my self tried this one in my live app which is completely built on firebase .

[Khyati Vara]

I have tried your code, but it shows error on signOut method

[Gastón Saillén]

in order to add the .addOnCompleteListener for signOut you need to implement Firebase UI like the docs on github states "The entry point to the authentication flow is the com.firebase.ui.auth.AuthUI class." Latest versions here github.com/firebase/FirebaseUI-Android/blob/master/auth/…

[Saneth]

Make sure you add the following before onCreate method: private FirebaseAuth firebaseAuth; private FirebaseUser firebaseUser;