public interface UserStrategy {
  User login();
}

@Service
public class AbstractUserStrategy {
  @Inject
  protected MessageService messageService;
}

@Service
@Log4j2
public class User1 extends AbstractUserStrategy implements UserStrategy {
  @Override
  public User login() {
...
    return user;
  }
}

public class CommonUserStrategy {
  private UserStrategy userStrategy;

  public CommonUserStrategy(UserStrategy userStrategy) {
    this.userStrategy = userStrategy;
  }

  public User login() {
    return userStrategy.login();
  }
}

@Service
@Log4j2
public class UserServiceImpl implements UserService {
  private static Map<String, CommonUserStrategy> userStrategyMap = new HashMap<String, CommonUserStrategy>();
...

  static {
    CommonUserStrategy user1 = new CommonUserStrategy(new User1());
    CommonUserStrategy user2 = new CommonUserStrategy(new User2());

    userStrategyMap.put(UserType.USER1.name(), user1);
    userStrategyMap.put(UserType.USER2.name(), user2);
  }

  @Override
  public User getUserByLoginPass(String login, String password, UserType userType) {
...
    CommonUserStrategy commonUserStrategy = userStrategyMap.get(userType.name());
    if (commonUserStrategy != null) {
      user = commonUserStrategy.login(userEntity, UserUtil.getAvatarUrl(userEntity, contentService));
    }
    return user;
  }
}