java - 当我保存实体时，从属集合会重复

Question

我有以下域映射:

@Entity
@Table(name = "terminal_admin_role")
public class AdminRole {

    @Id
    @Column(name = "role_id", nullable = false, unique = true)
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_id")
    @SequenceGenerator(name = "user_id", sequenceName = "user_id")
    private Long adminId;

    @Column(name = "role")
    private String role;

    public AdminRole(String role) {
        this.role = role;
    }

    public AdminRole() {
    }

    // get set

    @Override
    public String toString(){
        return role;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof AdminRole)) {
            return false;
        }

        AdminRole adminRole = (AdminRole) o;

        if (!role.equals(adminRole.role)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        return role.hashCode();
    }
}

和

@Entity
@Table(name = "terminal_admin")
public class TerminalAdmin {
    @ManyToMany(fetch=FetchType.EAGER,cascade=CascadeType.ALL)
    @JoinTable(name = "admin_role", joinColumns = { 
        @JoinColumn(name = "admin_id", nullable = false) }, 
        inverseJoinColumns = { @JoinColumn(name = "role_id", 
                nullable = false) })
    private Set<AdminRole> adminRoles;      
    //...
}

并执行以下代码:
Controller :

@RequestMapping(value = "/admin/addNewAdmin")
public String adminUsers(@ModelAttribute @Valid TerminalAdmin terminalAdmin,
        BindingResult bindingResult, ModelMap model, Principal principal, HttpSession session) {
    ...
    terminalAdmin.setCreateDate(Calendar.getInstance());
    terminalAdminService.saveTerminalAdmin(terminalAdmin);
    ...
 }

服务:

@Override
@Transactional
public void saveTerminalAdmin(TerminalAdmin newAdmin) {
    String rawPassword = newAdmin.getPassword();
    newAdmin.setPassword(passwordEncoder.encode(newAdmin.getPassword()));
    terminalAdminDao.save(newAdmin);
    emailService.sendAdminCreatedEmail(rawPassword, newAdmin.getEmail(), newAdmin.getAdminRoles());
    emailService.sendAdminRegisteredForAdminEmail(newAdmin);
}

道:

@Override
@Transactional
public void save(TerminalAdmin terminalAdmin) {
    sessionFactory.getCurrentSession().save(terminalAdmin);
}

之后，我看到绑定(bind)到用户的管理员角色在数据库的 AdminRole 表中重复。

我做错了什么？我写了 equals 方法。

附注

在调试中保存之前，我看到以下值:

Answer 1

因为在新的 TerminalAdmin 中，它引用的 AdminRole 不包含 ID。 ID是实体的身份。它不使用equals()来识别身份。如果没有 ID，Hibernate 只是将其视为新的 AdminRole 来持久化到数据库(因为您已在 TerminalAdmin 中设置了相应的级联选项)

您可以做出一些选择

1. 将您的 AdminRole ID 更改为 role 字符串，或/和
2. 通过 role 字符串查找正确的 AdminRole，并将其设置在新的 TerminalAdmin 实体中，或/和
3. 包含传入请求中的AdminRole ID等...