使用 mapstruct 如何使用 spring 组件映射器将对象映射到对象列表

Question

我正在尝试将对象 A 映射到对象 B 的列表。我有一个从对象 A 映射到对象 B 的映射器。

例如，我尝试了多种不同的方式尝试使用 'expressions' 创建包含一个对象 A 的列表 'qualifiedByName' 但这行不通，因为我认为当你使用 expressions/qualifiedByName 时你不能使用自定义映射器（我在这里可能是错的？）

我还尝试使用 @aftermapper 方法调用映射器获取目标映射器句柄的“mappers.getMapper” 但是我发现映射器中使用的 spring beans 没有人口的地方。 aftermapping 中的映射使得感觉我可以用源代码调用目标映射器然后将目标添加到列表中。所以我希望那里是从我的映射器获取映射器组件句柄的另一种方法。

我所有的映射器都使用 @Mapper(componentModel="spring",

欢迎所有建议下面是显示问题的代码示例。

此致，德克兰

    // SPECIESTOLOGSPECY.JAVA
    // From this mapper I want to call SpecyToLogDeclarationMapperApi mapper
    // to map ‘species’ to ‘logdeclarations’ which is a list of logdeclaration
    // you can see want I am trying to do in the aftermapping method
    // where I map species to logdeclaration and then put this into a list
    // unfortunately I need other mapping components (ConfigMapperFromCode & SpecyToFishDeclarationMapperApi)
    // to be autowired into  SpecyToLogDeclarationMapperApi and this is not happening.
    // is there another way to get a handle to the spring managed 
    // SpecyToLogDeclarationMapperApi mapper ?

     @Mapper(componentModel="spring",
     uses = {
         ConfigMapperFromCode.class, 
         GeoInfoMapper.class,
         SpecyToLogDeclarationMapperApi.class
            })
     public interface SpeciesToLogSpecy {
     SpecyToLogDeclarationMapperApi MAPPER = Mappers.getMapper(SpecyToLogDeclarationMapperApi.class);

@Mappings(
        {
            @Mapping(target="createdate", expression = "java(java.sql.Timestamp.valueOf(java.time.LocalDateTime.now()))"),
            @Mapping(target="speciesid", qualifiedByName={"ConfigMapperFromCode", "speciesIdFromCodeAsDecimal"},  source = "species.speciesCode"),
            @Mapping(target="unitweight", constant = "1"),
            @Mapping(target = "inactiveind", constant = "N"),
            @Mapping(target = "unitdefaultind", constant = "Y"),
            @Mapping(target = "sectiontypeid", expression = "java(new BigDecimal(ie.gov.agriculture.fisheries.logsheet.mapping.constants.MappingConstants.LOG_SPECIES_SECTION_TYPE_SHEETDECLARATION))"),
            @Mapping(target = "unituomid", expression = "java(new BigDecimal(ie.gov.agriculture.fisheries.logsheet.mapping.constants.MappingConstants.LOGSHEET_CATCHUNITS_KG))"),
            @Mapping(target="catchtypeid",  qualifiedByName={"ConfigMapperFromCode", "returnCatchTypeId"},  source = "species.spType"),
            @Mapping(target="legalfishsizetypeid",  qualifiedByName={"ConfigMapperFromCode", "legalFishSizeTypeIdFromCode"},  source = "species.fishSizeClass"),
            @Mapping(target="presenttypeid",  qualifiedByName={"ConfigMapperFromCode", "presentationTypeIdFromCode"},  source = "species.presentation.presentationType"),
            //@Mapping(target="logdeclarations", source = "species")                
        }           
         )
Logspecy speciesToLogspecy(Species species, @Context ExtraFields extraFields);


    @AfterMapping
    default void afterMap(@MappingTarget Logspecy logspecy, @Context ExtraFields extraFields){
    Logdeclaration logDeclaration = MAPPER.SpeciesToLogDeclarations(species, extraFields);

    List<Logdeclaration> logdeclarations = new ArrayList<Logdeclaration>(); 
    logdeclarations.add(logDeclaration);
    logSpecy.setLogdeclarations(logdeclarations);    
    {




    // SPECYTOLOGDECLARATIONMAPPERAPI.JAVA



    @Mapper(componentModel="spring",
    uses = {
        ConfigMapperFromCode.class,
        SpecyToFishDeclarationMapperApi.class       
        }    
)
public interface SpecyToLogDeclarationMapperApi {


@Mappings(
        {
            @Mapping(target="createdate", expression = "java(java.sql.Timestamp.valueOf(java.time.LocalDateTime.now()))"),              
            @Mapping(target="geartypeid", qualifiedByName={"ConfigMapperFromCode", "gearIdFromCode"},  source = "species.gearType"),
            @Mapping(target="fishcount", source = "species.qty"),
            @Mapping(target = "inactiveind", constant = "N"),
            @Mapping(target="packagetypeid", qualifiedByName={"ConfigMapperFromCode", "packagingTypeIdFromCode"},  source = "species.presentation.packaging"),
            @Mapping(target="packagecount", source = "species.presentation.pkgunit"),
            @Mapping(target="avgpackageweight", source = "species.presentation.pkgUnitWeight"),
            @Mapping(target="conversionfactor", source = "species.presentation.convFactor"),
            @Mapping(target="fishdeclaration", source = "species.geoInfo")              
        }           
        )
Logdeclaration SpeciesToLogDeclarations (Species species, @Context ExtraFields extraFields);

Answer 1

问题是您正在尝试将 Species 映射到 List<Logdeclaration>，而 MapStruct 找不到这样的映射方法。为了使其工作，您可以将以下方法添加到您的 SpecyToLogDeclarationMapperApi:

default List<Logdeclaration> SpeciesToLogDeclarationsToList(Species species, @Context ExtraFields extraFields) {
    if ( species == null ) {
        return null;
    }

    Logdeclaration logDeclaration = SpeciesToLogDeclarations(species, extraFields);

    List<Logdeclaration> logdeclarations = new ArrayList<Logdeclaration>();
    logdeclarations.add(logDeclaration);
    return logdeclarations;
}

这是一些额外的东西，我认为你可以做这些来改进你的代码并使用 MapStruct "more correctly":

当组件模型不是 default

Mappers#getMapper(Class)

如果您不想在表达式中使用 FQN，可以使用 Mapper#imports，MapStruct 将在实现中导入它们。
当您只有一个源参数时，您不必在映射中使用它的名称

例如

@Mapping(target="fishcount", source = "species.qty")

可以是

@Mapping(target="fishcount", source = "qty")

使用 mapstruct 如何使用 spring 组件映射器将对象映射到对象列表

using mapstruct how to map an object to a list of objects with spring component mappers

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