映射结构:当源为空时，目标不应设置为空 [英] Map struct : When source is null target should NOT be set to null

问题描述

我正在尝试使用 mapstruct 1.2.0.CR2 映射嵌套属性.(示例映射 customer.address.houseNumber 到 userDTO.homeDTO.addressDTO.houseNo).

I am trying to map nested properties using mapstruct 1.2.0.CR2. (Example map customer.address.houseNumber to userDTO.homeDTO.addressDTO.houseNo ).

期望:当 customer.address 为空时，我不想将 addressDTO 设置为空.由于 addressDTO 包含已从其他不同来源设置的countyname"和其他属性.

Expectation : I do not want to set the addressDTO to null when customer.address is null. Since addressDTO contains "countyname" and other properties which are already set from other different sources.

请告知是否有我可以设置的属性/设置，以便在源为空时目标不会设置为空.

Please advice if there is property/setting that I could set so that the target it not set to null when source is null.

@Mapper( nullValueCheckStrategy = NullValueCheckStrategy.ALWAYS )
public interface CustomerUserMapperNullCheck {

    @Mapping(source="address", target="homeDTO.addressDTO" )
    void mapCustomer(Customer customer, @MappingTarget  UserDTO userDTO)  ;

    @Mapping(source="houseNumber", target="houseNo" )
    void mapCustomerHouse(Address address, @MappingTarget  AddressDTO addrDTO)  ;

}

我最初尝试过像下面这样的单一映射

I initially tried in single mapping like below

@Mapping(target="homeDTO.addressDTO.houseNo", source="address.houseNumber")
 abstract void mapCustomerHouse(Customer customer, @MappingTarget  UserDTO userDTO)  ; 

然后尝试拆分映射，基于 https://github.com/mapstruct/映射结构/问题/649.

Then tried splitting up the mapping, based on https://github.com/mapstruct/mapstruct/issues/649.

两种方法都没有产生预期的结果/生成的方法代码

Both approaches does not produce the expected result/ Generated method code

 protected void customerToHomeDTO(Customer customer, HomeDTO mappingTarget) {
        if ( customer == null ) {
            return;
        }

        if ( customer.getAddress() != null ) {
            if ( mappingTarget.getAddressDTO() == null ) {
                mappingTarget.setAddressDTO( new AddressDTO() );
            }
            mapCustomerHouse( customer.getAddress(), mappingTarget.getAddressDTO() );
        }
        **else {
            mappingTarget.setAddressDTO( null );   // I dont want to else where addressDTO is set to null.
        }**
    }

完整的生成代码在这里
https://github.com/mapstruct/mapstruct/issues/1306

谢谢

推荐答案

@Mapper( nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE )

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