我在hibernate和一对一Map方面遇到了一些问题。
我的dto课程是这样的：
客户收件人

@Getter
    @Setter
    @NoArgsConstructor
    @AllArgsConstructor
    @ToString
    public class CustomerDTO {

        private String nic;
        private String name;
        private String address;
        private String contact;
        private ArrayList<UserDTO> user = new ArrayList<>();

用户DTO

@Getter
    @Setter
    @NoArgsConstructor
    @AllArgsConstructor
    @ToString
    public class UserDTO {

        private String email;
        private String password;
        private String role;
        private String lastLogged;
    }

我的实体类是这样的
顾客

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Entity
public class Customer {

    @Id
    private String nic;
    private String name;
    private String address;
    private String contact;

    @OneToOne(mappedBy = "customer", cascade = CascadeType.ALL)
    private User user;

用户

@Getter
    @Setter
    @NoArgsConstructor
    @AllArgsConstructor
    @Entity
    public class User {
        @Id
        private String email;
        private String password;
        private String role;
        private String lastLogged;

        @OneToOne(cascade = CascadeType.ALL)
        @JoinColumn(name = "cusNIC", referencedColumnName = "nic", nullable = false)
        private Customer customer;
}

CustomerController类

@RestController
    @RequestMapping("/api/v1/customer")
    @CrossOrigin
    public class CustomerController {
        @Autowired
        CustomerService customerService;

        @PostMapping(consumes = {MediaType.APPLICATION_JSON_VALUE})
        public ResponseEntity saveCustomer(@RequestBody CustomerDTO dto){

            customerService.saveCustomer(dto);
            StandradResponse success = new StandradResponse(200, "success", null);
            return new ResponseEntity(success, HttpStatus.OK);

        }

    }

customerservice类

@Transactional
    @Service
    public class CustomerServiceImpl implements CustomerService {

        @Autowired
        CustomerRepo customerRepo;

        @Autowired
        UserRepo userRepo;

        @Autowired
        ModelMapper mapper;

        @Override
        public void saveCustomer(CustomerDTO dto) {

            if(!customerRepo.existsById(dto.getNic())){

                Customer customer = mapper.map(dto, Customer.class);

                customerRepo.save(customer);

                for (UserDTO ud : dto.getUser()){
                    if(!userRepo.existsById(ud.getEmail())){

                        UserDTO userDTO = new UserDTO(ud.getEmail(),ud.getPassword(),ud.getRole(),ud.getLastLogged());

                        User user = new User(userDTO.getEmail(), userDTO.getPassword(), userDTO.getRole(), userDTO.getLastLogged(), customer);
                         //User user = mapper.map(userDTO, User.class);
                        userRepo.save(user);

                    }else {

                        throw  new RuntimeException("Email is already exist!");
                    }

                }

            }else{

                throw  new RuntimeException("Customer is already exist!");

            }

        }

我尝试使用postman发送这些json值

{

      "nic" : "55665v",
      "name" : "anyname",
      "address" : "no 20,56 text",
      "contact" : "54673453",

      "user": [{

        "email":"text@gmail.com",
        "password":"1234",
        "role":"driver",
        "lastLogged":"sunday"
      }]

}

每次我调用我的函数 ids for this class must be manually assigned before calling save(): lk.EasyCarRental.backend.entity.Customer; nested exception is org.hibernate.id.IdentifierGenerationException: ids for this class must be manually assigned before calling save(): lk.EasyCarRental.backend.entity.Customer 我不想自动生成id。我习惯于手动输入id