不能使用@mapper map 枚举值

Question

I'm trying to make an automatic mapper, but I'm having a problem with an Enum inside my DTO. In my @mapper class, I want everything to be automatically mapped except fthe Enum field. However, when debugging, I see that it does go into the mapper auto-implementation class, and it doesn't ignore my Enum as I indicate with @mapping

Example of my Entity and DTO

@Entity
public class Document {
    
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Integer id;

private String type;

My DTO:

@Data
public class DocumentDTO {

private Integer id;
private DocumentsEnum type;

How can I ignore the mapping for that specific enumerated field?

I have tried the following annotations on @mapping:

@Mapper
public interface DocumentsMapper {

@Mapping(source = "type", target = "type", ignore = true)
@Mapping(source = "DocumentsEnum", target = "DocumentsEnum", ignore = true)
@Mapping(source = "MAIN", target = "MAIN", ignore = true) // <-- This is the value of Enum
@Mapping(source = "ppal", target = "ppal", ignore = true) // <-- This is the name of Enum
List<DocumentDTO> mapper(List<Document> document);

@AfterMapping
default void afterMapping(Document document, @MappingTarget DocumentDTO documentDTO) {
    //some logic
}

Answer 1

The correct way to declare your Mapping to ignore the field you want to ignore is the first one, you can delete the others.

 @Mapping(source = "type", target = "type", ignore = true)

The reason that this isn't working for you as written is that you are technically mapping a List object to another List object. The List objects you pass in to be mapped will probably not have a type field (and definitely not the one you care about), the objects they hold ( Document and DocumentDTO ) will though.

To get this to work they way you would like you need two mappers: one for the List s and one for Document to DocumentDTO . Since the type field you want to ignore is on the latter objects, you should put the Mapping annotation on that method:

@Mapper
public interface DocumentsMapper {

List<DocumentDTO> listMapper(List<Document> document);

@Mapping(source = "type", target = "type", ignore = true)
DocumentDTO mapper(Document document);

The mapstruct library is smart enough to automatically use the mapper method to convert each element in your List in the listMapper method.