FirebaseAuth auth = FirebaseAuth.getInstance(); auth.signOut();
public class MainActivity extends AppCompatActivity{ private static final String TAG = "MainActivity"; private FirebaseAuth auth; private FirebaseUser user; private String name; private String photo; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); auth = FirebaseAuth.getInstance(); user = auth.getCurrentUser(); if (user == null) { startActivity(new Intent(this, SignInActivity.class)); finish(); return; } else { name = user.getDisplayName(); photo = user.getPhotoUrl().toString(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main_menu, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch(item.getItemId()){ case R.id.sign_out_menu: Log.d(TAG, "Sign Out"); auth.signOut(); startActivity(new Intent(this, SignInActivity.class)); finish(); default: return super.onOptionsItemSelected(item); } } }