使用 MapStruct 映射嵌套字段答案

【问题标题】：Map nested fields with MapStruct使用 MapStruct 映射嵌套字段
【发布时间】：2021-04-23 14:07:14
【问题描述】：

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;
}

还有这个 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/名称的部门
地区来自城市/部门/地区/名称

这是我的映射器：

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

【问题讨论】：

标签： java mapstruct

【解决方案1】：

当您映射嵌套字段时，您需要告诉 MapStruct 您希望从哪里以及如何使用 @Mapping 进行映射。

在你的情况下，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);
}

【讨论】：