Java 使用MapStruct映射嵌套字段

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;
}

此DTO：

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

在我的DTO中，我想映射

• 来自城市/部门/姓名的部门
• 来自城市/部门/地区/名称的地区

这是我的地图：

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

---

映射嵌套字段时，您需要告诉MapStruct要从何处以及如何使用

@mapping

进行映射

在您的情况下，它将如下所示：

@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);
}

---

映射嵌套字段时，您需要告诉MapStruct要从何处以及如何使用

@mapping

进行映射

在您的情况下，它将如下所示：

@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);
}