How to organize a complex DTO from multiple entities?

Question

Java

Let's say there is an entity user
the user has roles the role has permissions
the user has a subject

I do something for the data from the form, with the usual one I just encapsulate the input and form the entity.
And how do they do this when there are nestings, you can link to the article.

Answer 1

Well, you can create several DTOs by analogy with the necessary entities from the database.
For example,

class User {
Role role;
}
class Role {
List<Privilege> privileges;
}

class UserDto {
RoleDto role;
}
class RoleDto {
List<PrivilegeDto> privileges;
}

If the names match, then the mappers will be able to convert Dto <--> Entity, otherwise, you will need to customize the mappers or add the appropriate annotations. You can take the same MapStruct || ModelMapper or use springConverter<>