java - 在复合键中使用 JoinColumns 时出现错误的 TypeDescriptor

Question

我一直在绞尽脑汁，试图弄清楚以下映射有什么问题。我知道以下映射对于 ORM 来说并不理想，但数据库就是这样，我无法更改其结构。我正在使用 JPA 2.1 和 Hibernate 5.0.2.Final。

@MappedSuperclass    
public abstract class BaseEntity<T extends Serializable> implements Serializable {

    protected T id;

    @Id
    public T getId() {
        return id;
    }

    protected void setId(T id) {
        this.id = id;
    }
}

---

@Table(name = "campaign")
@AttributeOverride(name = "id", column = @Column(name = "campaign_id") )
public class Campaign extends BaseEntity<String> {
    // attributes, getters and setters
}

---

@Embeddable
public class CampaignBroadcastPK implements Serializable {

    @ManyToOne
    @JoinColumn(name = "campaign_id", insertable = false, updatable = false)
    private Campaign campaign;

    @Column(name = "broadcast_date")
    private LocalDate broadcastDate;

    // getters and setters
}

---

@Entity
@Table(name = "campaign_broadcast")
public class CampaignBroadcast implements Serializable {

    @EmbeddedId
    private CampaignBroadcastPK id;

    // attributes, getters and setters
}

---

@Embeddable
public class CampaignBroadcastProcessPK implements Serializable {

   @ManyToOne
   @JoinColumns({ 
       @JoinColumn(name = "campaign_id", insertable = false, updatable = false),
       @JoinColumn(name = "broadcast_date", insertable = false, updatable = false) 
    })
    private CampaignBroadcast broadcast;

    @Column(name = "process_date)
    private LocalDate processDate;

    // getters and setters
}

---

@Entity
@Table(name = "campaign_broadcast_process")
public class CampaignBroadcastProcess implements Serializable {

    @EmbeddedId
    private CampaignBroadcastProcessPK id;

    // attributes, getters and setters
}

---

除了这个结构，我还有一个转换器来处理 LocalDate 到 java.sql.Date，它用 autoApply=true 注释。

当我尝试通过 entityManager.find() 加载 CampaignBroadcastProcess 时，hibernate 会尝试将 campaign_id 转换为 Date，即使它被映射为一个字符串，导致 java.sql.Date 抛出一个 IllegalStateException，因为传递给 valueOf 的字符串不是有效的日期字符串。

我怀疑 Hibernate 混淆了 CampaignBroadcastProcessPK 上的 JoinColumns 类型，将它们都作为 LocalDate 处理。

有人遇到过这个问题吗？

Answer 1

我不太清楚为什么，但是改变两个 @JoinColum 的顺序解决了这个问题。现在的映射如下:

@ManyToOne
@JoinColumns({ 
    @JoinColumn(name = "broadcast_date", insertable = false, updatable = false),
    @JoinColumn(name = "campaign_id", insertable = false, updatable = false)     
})
private CampaignBroadcast broadcast;