扩展现有Mapstruct接口以添加其他映射方法

Question

@MapperConfig(uses = MyMapper.class)
public interface MyMapperExtended extends MyMapper {

    default List<ChildClass> someObjectListToChildClassList(List<SomeObject> someList) {
        //Some special logic here and looping which makes it so cannot use the @Mapping annotations
        
        //Call the mapper for the parent so that the base properties are mapped 
        ParentClass mappedParentClass = this.someObjectListToParentClassList(someList);
        
        //Uses a copy constructor to copy over the mapped base properties
        ChildClass myChildClass = new ChildClass(mappedParentClass);
        myChildClass.setExtraProperty("whatever value");

        return myChildClass;
    }
}

@Mapper(imports = { SomeUtilityClass.class })
public interface MyMapper {
    @Mapping(target = "id", source = "someId")
    @Mapping(target = "name", source = "name")
    @Mapping(target = "someFieldWeIgnoreWhileMapping", ignore = true)
    ParentClass someObjectListToParentClass(SomeObject someObject)

    List<ParentClass> someObjectListToParentClassList(List<SomeObject> someList)
}

public class ParentClass {
    UUID id; 
    String name;
    String someFieldWeIgnoreWhileMapping;

    public ParentClass() {}
}

public class ChildClass {
    String extraProperty; 

    public ChildClass(ParentClass parent) {
        super();
        this.setId(parent.getId());
        this.setName(parent.getName());
    }
}

public class SomeObject {
    UUID someId; 
    String name; 
    String someFieldWeIgnore; 

    public SomeObject () {}
}

Answer 1

在解决了几个不同的问题之后。我终于让它在生成代码的地方“工作”了，但它不适用于我的用例。我从上面发布的代码中排除了“表达式”的使用，因为我当时认为它不相关，但它导致了最后一个问题。

@Mapping(target = "id", source = "someId")
@Mapping(target = "name", source = "name")
@Mapping(target = "someFieldWeIgnoreWhileMapping", ignore = true)
@Mapping(expression = "java(SomeUtilityClass.doSomethingHelpful(someObject.getSpecialField()))", target = "specialField")
ParentClass someObjectListToParentClass(SomeObject someObject);

从Mapstruct生成的代码如下所示。

public ParentClass someObjectListToParentClass(SomeObject arg0) {
    if (arg0 == null) {
        return null;
    } else { 
        ParentClass parentClass = new ParentClass();
        parentClass.setId(arg0.getId()); 
        parentClass.setName(arg0.getName());

        //The problem. 
        //It puts the variable name as "someObject" because that's what the expression is hardcoded as in the Interface, but the varible is actually arg0 here 
        parentClass.setSpecialField(SomeUtilityClass.doSomethingHelpful(someObject.getSpecialField()));
    }
}

对于没有像我这样的场景的人来说，添加@mapper就可以了（包括所有导入，如果有的话）。我决定只做一个单独的映射器，而不是从原来的映射器继承。