一些说明:
因此,在中Account
,像这样修改映射:
@Entity
public class Account {
@Id @GeneratedValue
public Long id;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "account", orphanRemoval = true)
public List<Contact> contacts = new ArrayList<Contact>();
public void addToContacts(Contact contact) {
this.contacts.add(contact);
contact.setAccount(this);
}
public void removeFromContacts(Contact contact) {
this.contacts.remove(contact);
contact.setAccount(null);
}
// getters, setters
}
在中Contact
,重要的部分是该@ManyToOne
字段应将optional
标志设置为false
:
@Entity
public class Contact {
@Id @GeneratedValue
public Long id;
@ManyToOne(optional = false)
public Account account;
// getters, setters, equals, hashCode
}
Account account = new Account();
Contact contact = new Contact();
account.addToContact(contact);
em.persist(account);
em.flush();
assertNotNull(account.getId());
assertNotNull(account.getContacts().get(0).getId());
assertEquals(1, account.getContacts().size());
account.removeFromContact(contact);
em.merge(account);
em.flush();
assertEquals(0, account.getContacts().size());
和孤立的孤儿Contact
被删除,按预期方式。使用Hibernate 3.5.3-Final测试。