Map 嵌套字段與 MapStruct

Question

假設我有這些實體：

public class Address {
    private String id;
    private String address;
    private City city;
}

public class City {
    private int id;
    private Department department;
    private String zipCode;
    private String name;
    private Double lat;
    private Double lng;
}

public class Department {
    private int id;
    private Region region;
    private String code;
    private String name;
}

public class Region {
    private int id;
    private String code;
    private String name;
}

而這個 DTO：

public class AddressDTO {
    private String address;
    private String department;
    private String region;
    private String zipCode;
}

在我的 DTO 中，我想 map

• 來自城市/部門/名稱的部門
• 來自城市/部門/地區/名稱的區域

這是我的映射器：

@Mapper(componentModel = "spring")
public interface AddressMapper {
    AddressDTO addressToAddressDTO(Address item);
}

Answer 1

當您映射嵌套字段時，您需要告訴 MapStruct 您希望從哪里以及如何使用@Mapping進行映射。

在你的情況下，它看起來像：

@Mapper(componentModel = "spring")
public interface AddressMapper {
    
    @Mapping(target = "department", source = "city.department.name")
    @Mapping(target = "region", source = "city.department.region.name")
    @Mapping(target = "zipCode", source = "city.zipCode")
    AddressDTO addressToAddressDTO(Address item);
}