Is it impossible to use @SubMapping with multiple parameter? #3918

DENNIZ-777 · 2025-08-19T10:55:27Z

DENNIZ-777
Aug 19, 2025

Hello, I'm pretty new to Mapstruct and stuck with the problem below.
Please let me know if you have any idea.

I'm trying to map Phone, Book to PhoneDto, BookDto using ItemMapper with @SubclassMapping in Mapstruct.

The issue is during subclass mapping, the second parameter String imagePath gets ignored.

I checked the generated code and the method phoneToPhoneDto doesn't have second parameter.

@Mapper(componentModel = MappingConstants.ComponentModel.SPRING)
public abstract class ItemMapper {
    @SubclassMapping(source = Phone.class, target = PhoneDto.class)
    @SubclassMapping(source = Book.class, target = BookDto.class)
    public abstract ItemDto itemToItemDto(Item item, String imagePath);
}

Error:

ItemMapper.java:36: warning: Unmapped target property: "imagePath". Mapping from SubclassMapping for Phone "Phone phone" to "PhoneDto phoneDto".
    public abstract ItemDto itemToItemDto(Item item, String imagePath);

I also tried

@Mapper(componentModel = MappingConstants.ComponentModel.SPRING)
public abstract class ItemMapper {
    @SubclassMapping(source = Phone.class, target = PhoneDto.class)
    @SubclassMapping(source = Book.class, target = BookDto.class)
    public abstract Item itemToItemDto(Item item, @Context String imagePath);
}

in this way, phoneToPhoneDto is generated with second parameter, but Phone.getImagePath() is still null.

I think using custom method will solve the problem, but since there are alot of fields and many other childs in Item I would like to avoid writing the same mapping by myself(ex.this.itemId = item.getItemId()).

Answered by filiphr

Aug 24, 2025

@Context is meant exactly to be used this way. It is a way to pass certain things to other methods.

In any case, I see what you are looking for and I am not sure that it can work properly with @SubclassMapping. Those only create single parameter mapping methods. Perhaps we can improve this, but this would need a bit more work on our side

View full answer

DENNIZ-777 · 2025-08-19T15:15:08Z

DENNIZ-777
Aug 19, 2025
Author

In addition to my second try, I found a solution using @AfterMapping.

@Mapper(componentModel = MappingConstants.ComponentModel.SPRING)
public abstract class ItemMapper {
    @SubclassMapping(source = Phone.class, target = PhoneDto.class)
    @SubclassMapping(source = Book.class, target = BookDto.class)
    public abstract ItemDto itemToItemDto(Item item, @Context String imagePath);
}

@AfterMapping
    protected void fillImagePath(@MappingTarget PhoneDto dto, @Context String imagePath) {
        dto.setImagePath(imagePath);
}

I'm still curios whether this is the best solution or not(I feel like @Context is not meant to be used this way) .
Please let me know if you have any other solution for this:D

1 reply

filiphr Aug 24, 2025
Maintainer

@Context is meant exactly to be used this way. It is a way to pass certain things to other methods.

In any case, I see what you are looking for and I am not sure that it can work properly with @SubclassMapping. Those only create single parameter mapping methods. Perhaps we can improve this, but this would need a bit more work on our side

Answer selected by DENNIZ-777

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Is it impossible to use @SubMapping with multiple parameter? #3918

Uh oh!

{{title}}

Uh oh!

Replies: 1 comment 1 reply

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{title}}

Uh oh!

Select a reply

Uh oh!

Uh oh!

Is it impossible to use @SubMapping with multiple parameter? #3918

Uh oh!

DENNIZ-777 Aug 19, 2025

Replies: 1 comment · 1 reply

Uh oh!

DENNIZ-777 Aug 19, 2025 Author

Uh oh!

filiphr Aug 24, 2025 Maintainer

DENNIZ-777
Aug 19, 2025

Replies: 1 comment 1 reply

DENNIZ-777
Aug 19, 2025
Author

filiphr Aug 24, 2025
Maintainer