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();                         }                          // ...                     }                 });     }    } 

Answer 1

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