MapStruct/mapping接口字段/java

Question

以下是我的DTO：

bookdto.java：

@Data
@Document
public class BookDTO {

    @Id
    private UUID id;
    private BookSpecificationsDTO specifications;

}

BookSpecificationsDTO接口：

public interface BookSpecificationsDTO {
    BookSpecificationsTypeDTO type = null;

    default BookSpecificationsTypeDTO getType() {
        return type;
    }
}

public enum BookSpecificationsTypeDTO{

    CLASSIC,
    PHANTASY
}

@Data
public class ClassicBookSpecificationDTO implements BookSpecificationsDTO {
    private BookSpecificationsTypeDTO type = BookSpecificationsTypeDTO.CLASSIC;
    private String genre;
    private int length;
}

@Data
    public class PhantasyBookSpecificationDTO implements BookSpecificationsDTO {
        private BookSpecificationsTypeDTO type = BookSpecificationsTypeDTO.PHANTASY;
        private String genre;
   }

@Data
@Document
public class Book {

    @Id
    private UUID id;
    private BookSpecifications specifications;

}

书目规格界面：

public interface BookSpecifications {
    BookSpecificationsType type = null;

    default BookSpecificationsType getType() {
        return type;
    }
}

BookSpecificationStype：

public enum BookSpecificationsType{

    CLASSIC,
    PHANTASY
}

ClassicBookSpecification：

@Data
public class ClassicBookSpecification implements BookSpecifications {
    private BookSpecificationsType type = BookSpecificationsType.CLASSIC;
    private String genre;
    private int length;
}

@Data
    public class PhantasyBookSpecification implements BookSpecifications {
        private BookSpecificationsType type = BookSpecificationsType.PHANTASY;
        private String genre;
   }

@Mapper(componentModel = "spring", nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)
public interface BookMapper {
        
    @Mapping(target = "id", expression = "java(java.util.UUID.randomUUID())")
    Book toBook(BookDTO bookDTO);

}

java: The return type BookSpecificationsDTO is an abstract class or interface. Provide a non abstract / non interface result type or a factory method.

java: Can't map property "BookSpecificationsDTO specifications" to "BookSpecifications specifications". Consider to declare/implement a mapping method: "BookSpecifications map(BookSpecificationsDTO value)".

所以，我的问题是我能以某种方式得到这份工作吗？在这种情况下，如果其中一个字段是接口，是否可以将bookdto.java映射到book.java？提前感谢！

Answer 1

当目标类型是接口或抽象类时，必须具备以下条件之一：

• 用@objectFactory注释的方法，它将创建目标对象
• 使用@BeanMapping(resultType=xxx.class)定义结果类型的映射方法

在您的情况下，由于您的接口没有设置器，问题稍微复杂一些。因此，您需要对类型细化映射（或向下转换映射）的支持，这是当前的一个特性请求，还不可能开箱即用