public class BaseActivity extends AppCompatActivity implements AuthEventsReceiver.Receivable {
  private boolean isAuthorizationRequired = true;
  private int userId;
  private BroadcastReceiver broadcastReceiver;

  // readable setter
  public void allowGuestAccess() {
    this.isAuthorizationRequired = false;
  }
  // define getter for isAuthorizationRequired

  // define accessor for userId
  // set null if the userId is a negative number

  protected void onCreate(Bundle savedInstanceState) {
    // 略

    if (getIsAuhorizationRequired()) {
        registerReceivers();
        ensureAuthorized();
    }
  }

  private void ensureAuthorized() {
    setUserId(getDefaultSharedPreferences(this).getInt(USER_ID, -1));
    if (getUserId == null) {
      // do that what you want to do with unauthorized user
    }
  }

  protected void logout() {
    // ensure nullify the userId on the shared preferences

    Intent broadcastIntent = new Intent();
    broadcastIntent.setAction(AuthEventsReceiver.ACTION_LOGOUT);
    sendBroadcast(broadcastIntent);

    startLoginActivity();
  }

  @Override
  protected void onLogout() {
    finish();
  }

  protected void startLoginActivity() {
    // start your activity
  }

  private void registerReceivers() {
      IntentFilter intentFilter = new IntentFilter(AuthEventsReceiver.ACTION_LOGOUT);
      broadcastReceiver = new AuthEventsReceiver(this);
      registerReceiver(broadcastReceiver, intentFilter);
  }

  @Override
  protected void onDestroy() {
      super.onDestroy();
      unregisterReceiver(broadcastReceiver);
  }
}

public class AuthEventsReceiver extends BroadCastReceiver {
  public static final String ACTION_LOGOUT = "com.example.sozu.hoge.action_logout";
  private Activity activity;

  public AuthEventsReceiver(Activity activity) { this.activity = activity; }

  @Override
  public void onReceive(Context context, Intent intent) {
    try {
      AuthReceiver receiver = (Receivable) activity;
      switch (intent.getAction()) {
        case ACTION_LOGOUT:
          receivable.onLogout();
          break;
        case default:
          break;
      }
    } catch (ClassCastException e) {
      throw new ClassCastException("Activity must implement AuthEventsReceiver.AuthReceivable");
    }
  }

  public interface Receivable {
    void onLogout();
  }
}