使用@MappingTarget的Mapstruct不会调用lombok Builder build（）

Question

我正在尝试使用Mapstruct映射和Lombok Builder创建补丁方法。但在生成的代码中缺少build()调用

删除空值的Mapper：

@Mapper(
        nullValueCheckStrategy = NullValueCheckStrategy.ALWAYS,
        nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE

)
public interface CartMapper {
    CartMapper INSTANCE = Mappers.getMapper(CartMapper.class);

    Cart cartRequestToCart(CartRequest cartRequest);

    Cart patch(CartRequest cartRequest, @MappingTarget Cart cart);
}

嵌套类具有与Cart相同的lombok注释：

@Builder
@AllArgsConstructor(access = AccessLevel.PACKAGE)
@Getter
@Setter
@FieldDefaults(level = AccessLevel.PRIVATE)
public class Cart {

    Customer customer;
    Owner owner;
    Integer price;
    String voucher;
}

所有嵌套类都具有与CartRequest相同的lombok注释，并且结构与目标实体结构相同

@Data
@FieldDefaults(level = AccessLevel.PRIVATE)
public class CartRequest {
    CustomerRequest customer;
    OwnerRequest owner;
    Integer price;
    String voucher;
}

方法cartRequestToCart一切正常，在这里调用构建器，也在嵌套方法中调用

    @Override
    public Cart cartRequestToCart(CartRequest cartRequest) {
        if ( cartRequest == null ) {
            return null;
        }

        CartBuilder cart = Cart.builder();

        if ( cartRequest.getCustomer() != null ) {
            cart.customer( customerRequestToCustomer( cartRequest.getCustomer() ) );
        }
        if ( cartRequest.getOwner() != null ) {
            cart.owner( ownerRequestToOwner( cartRequest.getOwner() ) );
        }
        if ( cartRequest.getPrice() != null ) {
            cart.price( cartRequest.getPrice() );
        }
        if ( cartRequest.getVoucher() != null ) {
            cart.voucher( cartRequest.getVoucher() );
        }

        return cart.build();
    }

对于方法patch生成这个和这里在一些setters缺少build()调用

    @Override
    public Cart patch(CartRequest cartRequest, Cart cart) {
        if ( cartRequest == null ) {
            return null;
        }

        if ( cartRequest.getCustomer() != null ) {
            if ( cart.getCustomer() == null ) {
                cart.setCustomer( Customer.builder() ); // HERE build() missing
            }
            customerRequestToCustomer1( cartRequest.getCustomer(), cart.getCustomer() );
        }
        if ( cartRequest.getOwner() != null ) {
            if ( cart.getOwner() == null ) {
                cart.setOwner( Owner.builder() ); // HERE build() missing
            }
            ownerRequestToOwner1( cartRequest.getOwner(), cart.getOwner() );
        }
        if ( cartRequest.getPrice() != null ) {
            cart.setPrice( cartRequest.getPrice() );
        }
        if ( cartRequest.getVoucher() != null ) {
            cart.setVoucher( cartRequest.getVoucher() );
        }

        return cart;
    }

一些提示如何解决这个问题？非常感谢。

Answer 1

这是MapStruct 1.3.0.Final中的一个错误。

我建议按照mapstruct/mapstruct#1742进行修复。

目前的解决方案是通过SPI设置NoOpBuilderProvider来完全禁用构建器。