ManyToOne未与父ID映射

Question

我发现了其他有相同错误的主题，但没有一个似乎涵盖了我的问题。

你能帮我弄清楚是什么问题吗？

多谢！

import lombok.AccessLevel;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.NonNull;
import lombok.Setter;
import lombok.experimental.Accessors;

@Accessors(fluent = true)
@Data
@Entity
@NoArgsConstructor
public class BusinessDomain {
    @Setter(AccessLevel.NONE)
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long id;

    @NonNull
    @Column(unique=true)
    private String name;

    @OneToMany(mappedBy = "domain", cascade = CascadeType.ALL, orphanRemoval = true)
    private Set<BusinessSubDomain> subDomains = new LinkedHashSet<>();

    public void addSubDomain(BusinessSubDomain subDomain) {
        subDomains.add(subDomain);
    }
}

@Accessors(fluent = true)
@Data
@Entity
@NoArgsConstructor
public class BusinessSubDomain {
    @Setter(AccessLevel.NONE)
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long id;

    @ManyToOne(optional = false)
    @JoinColumn(name = "business_domain_id", referencedColumnName="id")
    private BusinessDomain domain;
}

@Override
public BusinessDomain saveOrUpdate(BusinessDomain businessDomain) throws OrcaException {
    try {
        BusinessDomain domain = businessDomainRepository.findByName(businessDomain.name());
        if(null == domain) {
        // Repository class not overriden (extends CrudRepository<BusinessDomain, Long>)
            return businessDomainRepository.save(businessDomain);
        } else {
            domain.description(businessDomain.description());
            domain.subDomains(businessDomain.subDomains());
            return businessDomainRepository.save(domain);
        }
    } catch (Exception e) {
        throw new OrcaException(e);
    }
}

@RunWith(SpringRunner.class)
@SpringBootTest
public class BusinessDomainTest {
    @Test
    @Transactional
    public void createBusinessDomainWithSubDomain() throws OrcaException {
        BusinessDomain passengerBusinessDomain = new BusinessDomain().name(DOMAIN_NAME).description(DOMAIN_DESCRIPTION);
        BusinessSubDomain distributionBusinessSubDomain = new BusinessSubDomain().name(SUBDOMAIN_NAME)
                .description(SUBDOMAIN_DESCRIPTION);
        passengerBusinessDomain.addSubDomain(distributionBusinessSubDomain);
        businessDomainService.saveOrUpdate(passengerBusinessDomain);
        BusinessDomain domain = businessDomainService.findByName(DOMAIN_NAME);
    }
}

Answer 1

我终于明白了。

首先，实体加法器必须是

public void addSubDomain(BusinessSubDomain subDomain) {
    subDomains.add(subDomain);
    subDomain.domain(this);
}

但这会导致无限调用哈希方法的无限循环。