How Can I mapping DTOs using mapstruct?

Question

I am tring to mapping entity datas to DTOs using mapstruct. And with these sources, I could map id,title datas. But the problem is.... I can not map userName using these sources.

How can I resolve this problem??

@Entity // DB와의 연결을 위하여
@Data   // getter setter
public class Board {
    @Id // id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull
    @Size(min=2, max=30)
    private String title;

    @Length(min=20)
    @Lob
    @Column(columnDefinition="TEXT", nullable = false)
    private String content;

    @ManyToOne
    @JoinColumn(name="userId", referencedColumnName = "id")
    private User user;
}

@Builder
@AllArgsConstructor
@Data
public class BoardListDto {
    private Long id;
    private String title;
    private String userName;
}

@Mapper(componentModel = "spring")
public interface BoardListMapper extends EntityMapper<BoardListDto, Board> {
    @Override
    @Mapping(target = "userName", source = "user.name.value")
    List<BoardListDto> toDtos(List<Board> board);

}

public interface EntityMapper <D, E> {
    E toEntity(D dto);
    D toDto(E entity);

    // Entity업데이트 시 null이 아닌 값만 업데이트 하도록 함.
    @BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)
    void updateFromDto(D dto, @MappingTarget E entity);

    List<D> toDtos(List<E> entity);
}

Answer 1

no need to implement toDtos method for this. This code should be enough and Mapstruct will handle the rest alone.

@Mapper(componentModel = "spring")
public interface BoardListMapper extends EntityMapper<BoardListDto, Board> {
    @Override
    @Mapping(target = "userName", source = "user.name")
    BoardListDto toDto(Board board);

}