MapStruct将新的计算字段添加到dto [英] MapStruct add a new calculated field to the dto

问题描述

我正在尝试使用MapStruct将实体Order映射到OrderDTO.我想在OrderDTO中添加一个新字段total，该字段在原始实体Order中不可用，应使用Order中的可用信息(订单输入价格，数量，税项)进行计算. ). 我在OrderDTO中创建了一个新字段total，我试图通过向映射器界面添加默认方法来映射它:

I'm trying to map an entity Order to a OrderDTO using MapStruct. I want to add to OrderDTO a new field total, this field is not available in the original entity Order and should be calculated using the information available in the Order (order entries price, quantity, taxes...). I created a new field total in the OrderDTO and I'm trying to map it by adding a default method to the mapper interface:

public interface OrderMapper {

    ...

    default BigDecimal orderToTotal(Order order){
        return logicToCalculateTotal();
    }
}

当我吃午餐时，构建MapStruct会启动错误

When I lunch the build MapStruct launch the error

未映射的目标属性:总计".

Unmapped target property: "total".

有什么办法解决这个问题吗?

Any idea how to solve this problem?

谢谢

推荐答案

有多种方法可以实现您所需要的.第一种方法是使用@AfterMapping或@BeforeMapping.如果这样做，您的代码将如下所示:

There are multiple way to achieve what you need. The first way is to use @AfterMapping or @BeforeMapping. If you go with this your code will look like:

public interface OrderMapper {

    @Mapping(target = "total", ignore = true) // Needed so the warning does not shown, it is mapped in calculateTotal
    OrderDto map(Order order);

    @AfterMapping // or @BeforeMapping
    default void calculateTotal(Order order, @MappingTarget OrderDto dto) {
        dto.setTotal(logicToCalculateTotal());
    }
}

另一种方法是像开始时那样做，但是必须说total是从Order映射的.

The alternative approach would be to do like you started, but you have to say that total is mapped from the Order.

您在替代方法中的映射器将是:

Your mapper in the alternative approach would be:

public interface OrderMapper {

    @Mapping(target = "total", source = "order")// the source should be equal to the property name
    OrderDto map(Order order);

    default BigDecimal orderToTotal(Order order) {
        return logicToCalculateTotal();
    }
}

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