Spring 启动 JPA 更新仅更新特定字段

Question

So I encountered this issue with updating an entity in DB. while Passing a whole entity and updating only specific fields it treats untouched fields as null, as a result I get an exception since those fields are @Not-Null ,

I have tried looking for similar problems but could not fix my problem.

Company ENTITY:

@Entity
@Table (name = "companies")
@Data
@ToString(exclude = "perfumes")
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class Company {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    @NotNull
    private String name;

    @NotNull
    @Email(message = "Wrong input. please enter a VALID email address")
    private String email;

    @NotNull
    @Size(min = 4, max = 14, message = "Password range must be between 4 - 14 digits")
    private String password;

    @NotNull
    @Enumerated(EnumType.STRING)
    private Country country;

    @Singular
    @OneToMany(mappedBy = "company", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private List<Perfume> perfumes = new ArrayList<>();
}

Most fields are @NotNull for creation, however, I need to update the entity, sometimes only specific fields.

Service:

@Override
public String updateCompany(int id, Company company) throws DoesNotExistException {
    if(!companyRepository.existsById(id))
    {
        throw new DoesNotExistException(id);
    }

    companyRepository.saveAndFlush(company);
    return company.getName() + " has been UPDATED";
}

as you can see an ENTITY has been passed which causes rest of attributes to be automatically null if not modified.

Controller:

  @PutMapping("/updateCompany/{id}")
    @ResponseStatus(HttpStatus.ACCEPTED)
    public String updateCompany(@PathVariable int id, @RequestBody Company company) throws DoesNotExistException {
        return admin.updateCompany(id,company);
    }

EXCEPTION:

Validation failed for classes [com.golden.scent.beans.Company] during update time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='must not be null', propertyPath=password, rootBeanClass=class com.golden.scent.beans.Company, messageTemplate='{javax.validation.constraints.NotNull.message}'}
]

Thanks.

Answer 1

The controller is binding the values you pass in to a new Company entity. The new entity is not attached to the persistence context, it does not have the state of the pre-existing entity. When you save it JPA thinks you want to null out all the fields you don't have values for.

Instead, you could have the controller bind its arguments to a DTO. Then in the service you look up the existing Customer, using findById, and copy the fields you want updated from the DTO to the entity. Then call saveAndFlush passing in the updated entity.

It looks like there's an improvement over the DTO, you can use aJsonPatch to hold the updates passed in, see https://www.baeldung.com/spring-rest-json-patch On the server the important thing is to look up the existing entity so that you have an entity that is attached to the persistence context and has all its fields current.