Can not map Enum value with @mapper-CodePudding

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
}

CodePudding user response：

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 Lists 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 Lists in the listMapper method.