Mapstruct 集合映射 从相同的源类映射扩展类异常问题—— Ambiguous mapping methods found for mapping collection element

ZhaoYingChao88 2020-11-13 02:08:54
集合 映射 mapstruct 相同


问题1:

票证实体

public class Ticket {
private long id;
private String title;
private Set<Comment> comments;
// Getters and setters
}


票证DTO (父类)

public class TicketDTO {
private long id;
private String title;
// Getters and setters
}


带有注释的票证DTO

public class TicketWithCommentsDTO extends TicketDTO {
private List<CommentDTO> comments;
// Getters and setters
}


票务映射器界面

@Mapper(uses= { CommentMapper.class })
public interface TicketMapper {
TicketDTO mapToTicketDTO(Ticket ticket);
List<TicketDTO> mapToTicketDTOList(Collection<Ticket> tickets); // Adding this method or the last method causes the error
TicketWithCommentsDTO mapToTicketWithCommentsDTO(Ticket ticket);
List<TicketWithCommentsDTO> MapToTicketWithCommentDTOList(Collection<Ticket> tickets);
}


评论映射器界面

@Mapper
public interface CommentMapper {
CommentDTO toCommentDTO(Comment comment);
List<CommentDTO> toCommentDTOList(Collection<Comment> comments);
}


引发的错误:

 Ambiguous mapping methods found for mapping collection element to
dto.TicketDTO: dto.TicketDTO mapToTicketDTO(model.Ticket ticket),
dto.TicketWithCommentsDTO mapToTicketWithCommentsDTO(model.Ticket ticket).

最佳答案

这是一个简单的修复,确实是缺少的配置问题。缺少的是@IterableMapping批注。
 

@IterableMapping


elementTargetType设置为正确的类型。

正确的Mapper代码

@Mapper(uses = { CommentMapper.class })
public interface TicketMapper {
TicketDTO mapToTicketDTO(Ticket ticket);
@IterableMapping(elementTargetType = TicketDTO.class)
List<TicketDTO> mapToTicketDTOList(Collection<Ticket> tickets);
TicketWithCommentsDTO mapToTicketWithCommentsDTO(Ticket ticket);
@IterableMapping(elementTargetType = TicketWithCommentsDTO.class)
List<TicketWithCommentsDTO> mapToTicketWithCommentDTOList(Collection<Ticket> tickets);
}

========================

问题2: 多集合Mapping异常 BaseDO 为父类

 /**
* dtoToDO
*
* @param dto
* @return
*/
ObjectControlDO dtoToDO(ObjectControlDto dto);
/**
* dtosToDOs
*
* @param dtos
* @return
*/
List<ObjectControlDO> dtosToDOs(List<ObjectControlDto> dtos);
/**
* dtoToDO
*
* @param dto
* @return
*/
BaseDO dtoToBaseDO(ObjectControlDto dto);
/**
* dtosToDOs
*
* @param dtos
* @return
*/
List<BaseDO> dtosToBaseDOs(List<ObjectControlDto> dtos);

解决方式

/**
* dtoToDO
*
* @param dto
* @return
*/
@Named(value = "dtoToDO")
ObjectControlDO dtoToDO(ObjectControlDto dto);
/**
* dtosToDOs
*
* @param dtos
* @return
*/
@IterableMapping(qualifiedByName = "dtoToDO")
List<ObjectControlDO> dtosToDOs(List<ObjectControlDto> dtos);
/**
* dtoToDO
*
* @param dto
* @return
*/
@Named(value = "dtoToBaseDO")
BaseDO dtoToBaseDO(ObjectControlDto dto);
/**
* dtosToDOs
*
* @param dtos
* @return
*/
@IterableMapping(qualifiedByName = "dtoToBaseDO")
List<BaseDO> dtosToBaseDOs(List<ObjectControlDto> dtos);

3、 mapstruct-将父字段值传播给嵌套对象的集合

可以将值从父对象传播到嵌套对象的集合

DTO源类

class CarDTO {
private String name;
private long userId;
private Set<WheelDto> wheels;
};
class WheelDto {
private String name;
}


目标实体类

class Car {
private String name;
private long userId;
private Set<Wheel> wheels;
};
class Wheel {
private String name;
private long lastUserId;
}


如您所见,我在WheelDto上没有lastUserId,因此我想在wheel集合中的每个对象上将CarDto的userId映射到WheelDto的lastUserId。

最佳答案

当前无法传递属性。但是,您可以通过@AfterMapping和/或@Context解决此问题。

汽车映射后更新车轮

但是,这意味着您需要对Wheel进行两次迭代。它看起来像

@Mapper
public interface CarMapper {
Car map(CarDto carDto);
@AfterMapping
default void afterCarMapping(@MappingTarget Car car, CarDto carDto) {
car.getWheels().forEach(wheel -> wheel.setLastUserId(carDto.getUserId()));
}
}


在映射轮时传递@Context以便在映射期间具有状态

如果您只想通过Wheel进行一次迭代,则可以传递一个@Context对象,该对象将在映射汽车之前从CarDto获取userId,然后在之后的映射中将其设置在Wheel上。该映射器如下所示:

@Mapper
public interface CarMapper {
Car map(CarDto carDto, @Context CarContext context);
Wheel map(WheelDto wheelDto, @Context CarContext context);
}
public class CarContext {
private String lastUserId;
@BeforeMapping
public void beforeCarMapping(CarDto carDto) {
this.lastUserId = carDto.getUserId();
}
@AfterMapping
public void afterWheelMapping(@MappingTarget Wheel wheel) {
wheel.setLastUserId(lastUserId);
}
}

CarContext将传递到车轮映射方法。

Mapstruct-从多个集合映射到单个集合

使用MapStruct,我的源对象中有两个集合,其中包含略有不同的对象。我想将这两个集合的对象映射为通用类型,然后将它们全部插入单个集合中。类似于以下内容:
 

List<UserNumber> listsToDtoList(List<PhoneNumber> phoneNumbers, List<FaxNumber> faxNumbers);
UserNumber phoneToPhoneDto(PhoneNumber phone);
UserNumber faxToPhoneDto(FaxNumber fax);


使用MapStruct做到这一点的最简单方法是什么?

最佳答案

因此,我将根据我的SourceObject进行映射(不写List<UserNumber> listsToDtoList(List<PhoneNumber> phoneNumbers, List<FaxNumber> faxNumbers);

所以大致如下:

@Mapping( target = "userNumbers", source = "phoneNumbers" )
Target map( Source source );
@AfterMapping // will be applied in the final part of the previous method
default void map ( Source source, @MappingTarget Target target ) {
target.getUserNumbers().addAll(source.getFaxNumbers());
}

 

 参照:

https://mapstruct.org/documentation/stable/reference/html/

版权声明
本文为[ZhaoYingChao88]所创,转载请带上原文链接,感谢
https://zyc88.blog.csdn.net/article/details/108286585

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