#Notnull on update not on add - spring-boot

Question

I have a model class which is used in post(create) and put(update) rest API
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.NonNull;
import lombok.Setter;
#Getter
#Setter
#NoArgsConstructor
#Entity(name= "employee")
public class employeeDetail {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Long employeeId;
#NonNull
private String employeeName;
}
So since employee id to be nullable on add, while it has to be passed when update operation. What is the best to implement?
Note: In this case employee id is a primary key, the same situation is possible for non-primary key fields as well. I use Spring boot, Spring data JPA and hibernate. Database is mariadb.

Answer 1

Something like this:
import com.fasterxml.jackson.annotation.JsonInclude;
import lombok.Data;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.transaction.Transactional;
import javax.validation.Valid;
import javax.validation.constraints.NotNull;
import java.util.Optional;
#Getter
#Setter
#NoArgsConstructor
#Entity(name = "employee")
class EmployeeDetail {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long employeeId; //Long is better!
#NotNull
private String employeeName;
// Needed just for conversion -> use some mapper, and remove this constructor
public EmployeeDetail(EmployeeDetailDTO employeeDetailDTO) {
this.employeeId = employeeDetailDTO.getEmployeeId();
this.employeeName = employeeDetailDTO.getEmployeeName();
}
}
interface EmployeeDetailRepo extends JpaRepository<EmployeeDetail, Long> {
}
#Data
#JsonInclude(JsonInclude.Include.NON_NULL)
class EmployeeDetailDTO {
private Long employeeId;
#NotNull
private String employeeName;
// Other fields
// Needed just for conversion -> use some mapper, and remove this constructor
public EmployeeDetailDTO(EmployeeDetail employeeDetail) {
this.employeeId = employeeDetail.getEmployeeId();
this.employeeName = employeeDetail.getEmployeeName();
}
}
#Service
class EmpDetailService {
private EmployeeDetailRepo employeeDetailRepo;
#Autowired
public EmpDetailService(EmployeeDetailRepo employeeDetailRepo) {
this.employeeDetailRepo = employeeDetailRepo;
}
public EmployeeDetailDTO add(EmployeeDetailDTO employeeDetailDTO) {
// map EmployeeDetailDTO to EmployeeDetail
EmployeeDetail employeeDetail = new EmployeeDetail(employeeDetailDTO);
EmployeeDetail employeeDetail1FromDB = employeeDetailRepo.save(employeeDetail);
// map back to dto
return new EmployeeDetailDTO(employeeDetail1FromDB);
}
#Transactional
public EmployeeDetailDTO edit(Long id, EmployeeDetailDTO employeeDetailDTO) {
// map EmployeeDetailDTO to EmployeeDetail
Optional<EmployeeDetail> byId = employeeDetailRepo.findById(id);
EmployeeDetail employeeDetailFromDB = byId.orElseThrow(() -> new RuntimeException("No such user with id: " + id));
employeeDetailFromDB.setEmployeeName(employeeDetailDTO.getEmployeeName());
return new EmployeeDetailDTO(employeeDetailFromDB);
}
}
#RequestMapping
class Controller {
private EmpDetailService empDetailService;
#Autowired
Controller(EmpDetailService empDetailService) {
this.empDetailService = empDetailService;
}
#PostMapping("/add")
public ResponseEntity<EmployeeDetailDTO> add(#Valid #RequestBody EmployeeDetailDTO employeeDetailDTO) {
EmployeeDetailDTO added = empDetailService.add(employeeDetailDTO);
return new ResponseEntity<>(added, HttpStatus.OK);
}
#PostMapping("/edit/{id}")
public ResponseEntity<EmployeeDetailDTO> edit(#PathVariable Long id,
#Valid #RequestBody EmployeeDetailDTO employeeDetailDTO) {
EmployeeDetailDTO edited= empDetailService.edit(id, employeeDetailDTO);
return new ResponseEntity<>(edited, HttpStatus.OK);
}
}

Answer 2

Since you expect Hibernate to generate yuor id on insert it should be nullable, so its type.
Just change employeeId to Integer.
From a design point of view, consider to create 2 different business domain classes, one for insert with no id and one for update/select with non nullable id.
public class EmployeeRegistration {
#NonNull
private String name;
}
public class EmployeeDetail {
#NonNull
private Integer employeeId;
#NonNull
private String name;
}
Then provade methods to transform them to database entities.