用MapStruct映射嵌套字段

Question

假设我有这些实体：

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;
}

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

null

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

Answer 1

当映射嵌套字段时，需要告诉MapStruct您希望在哪里以及如何使用@mapping进行映射。

在您的情况下，它看起来像：

@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);
}