为什么 Orika 将嵌套列表的未使用字段映射为 null？

Question

两个实体：Customer、CustomerAddress - Customer 有 List<CustomerAddress>

public class Customer implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    private String name;

    //bi-directional many-to-one association to CustomerAddress
    @OneToMany(mappedBy="customer", fetch=FetchType.EAGER, cascade=CascadeType.ALL)
    private List<CustomerAddress> customeraddresses;

    private String identifier;

    private String aliasId;

    @Temporal(TemporalType.TIMESTAMP)
    @Column(updatable=false)
    private Date createdDateTime;

    // Getters and Setters
}
public class CustomerAddress implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    private String line;

    //bi-directional many-to-one association to Customer
    @ManyToOne
    @JoinColumn(name="customerId")
    private Customer customer;

    @Temporal(TemporalType.TIMESTAMP)
    @Column(updatable=false)
    private Date createdDateTime;

    private String gisLocation;

    // Getters and Setters
}

相应的 DTO：

public class CustomerDTO {
    private int id;
    private String name;
    private String aliasId;
    private List<CustomerAddressDTO> customeraddresses;
    // Getters and Setters
}
public class CustomerAddressDTO {
    private int id;
    private String line;
    // Getters and Setters
}

注意：实体中存在未在 DTO 中使用的未使用/额外字段

来自更新方法的片段：

Customer oldCustomer = customerDao.getCustomerById(dto.getId());
mapper.map(dto, oldCustomer);

现在，在这个映射器调用之后，List 中未使用的字段被设置为 null（这是不对的）

确保 Orika 保留嵌套列表中未使用的字段的正确方法是什么？

---

（如果需要，请提供其他信息）：

oldCustomer before mapping: Customer [id=2, name=Customer1, customeraddresses=[CustomerAddress [id=7, line=ABCD**, createdDateTime=Sat Jan 01 00:00:00 IST 2000, gisLocation=1], CustomerAddress [id=13, line=0000, createdDateTime=Mon Jan 01 00:00:00 IST 2001, gisLocation=2]], identifier=id1, aliasId=1234, createdDateTime=Tue Dec 12 00:00:00 IST 2000]
dto used for mapping: CustomerDTO [id=2, name=Customer1, aliasId=1234, customeraddresses=[CustomerAddressDTO [id=7, line=ABCD**], CustomerAddressDTO [id=13, line=0000]]]
oldCustomer after mapping: Customer [id=2, name=Customer1, customeraddresses=[CustomerAddress [id=7, line=ABCD**, createdDateTime=null, gisLocation=null], CustomerAddress [id=13, line=0000, createdDateTime=null, gisLocation=null]], identifier=id1, aliasId=1234, createdDateTime=Tue Dec 12 00:00:00 IST 2000]

（注意：createdDateTime 和 gisLocation 设置为 null - 这些应保留原始值）

Answer 1

在 Orika 这是默认行为，您也可以通过提供合并两个集合的映射器来自定义此行为。项目的测试代码中有例子。

请查看此示例：CustomMerge