AtomKrieg

if (!isRequested()) {
 requestRegister(numberField.getText().toString());
 return;
}

if (rulesField.isChecked()) {
    register(numberField.getText().toString(), codeField.getText().toString());
} else {
    showMessage(R.string.error_rules);
}

public interface Service {}
public class AuthorizationService implements Service {}
public class UserMenuService implements Service {}
public class AdminMenuService implements Service {}

public class ServiceFactory {
    public static final int AUTHORIZATION = 1;
    public static final int USERMENU = 2;
    public static final int ADMINMENU = 3;

    public static Service create(int id) throws Exception {
        switch (id) {
            case AUTHORIZATION: return new AuthorizationService();
            case USERMENU: return new UserMenuService();
            case ADMINMENU: return new AdminMenuService();
            default: throw new Exception("service factory wrong id:" + id);
        }
    }
}