Spring JPA更新实体

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;
    private Integer age;

    // 省略getter和setter方法
}

public interface UserRepository extends JpaRepository<User, Long> {
}

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;

    public void updateUser(Long id, String newName, Integer newAge) {
        Optional<User> optionalUser = userRepository.findById(id);
        if (optionalUser.isPresent()) {
            User user = optionalUser.get();
            user.setName(newName);
            user.setAge(newAge);
            userRepository.save(user);
        }
    }
}