I have a particular aversion to the @RepositoryRestResource annotation which sends shivers down my spine.

and when you want to add a language it just adds more noise

by default (especially if you use spring boot) you can defer that responsibility to the jackson converter

@Todor Atanasov Thanks for the pointer. But http://modelmapper.org/ does not support Kotlin yet. However I did come across http://mapstruct.org/ . It seems promising and it has better support for Kotlin out of the box. Here is an illustration: https://github.com/mapstruct/mapstruct-examples/tree/master/mapstruct-kotlin

In my current project, we have hard coded the mappings in a very similar way to what you have in your example. In addition we have constructors in the entity model that take the DTO when saving back to the database. But we did run into a number of issues. 1) Lazy lists were getting fetched which didn’t need to be fetched. For instance, we have a

User

, which has a list of previous passwords. This

User

is used in may other classed to track who created or updated that object. As a result, whenever we transfer those other objects over and back between DTOs we need to populate the lazy password history. We got around this by creating a

UserSummary

, but it was still not ideal. 2) Parent child relationships were never simple. We got around this used

init

blocks like before, but again I was never happy with them as any simple update to the user would result in the password history getting fetched from the database.

@Entity(name = "users")
data class User(
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    var id: PersistanceId = -1,

    @OneToMany(mappedBy = "user", cascade = [CascadeType.ALL], orphanRemoval = true)
    @OrderBy("id DESC")
    val passwordHistory: List<Password> = mutableListOf(),
) {

    constructor(
        user: User,
        passwordHistory: List<PersistedPassword>,
    ) : this(  ... )

    init {
        passwordHistory.forEach { it.user = this }
    }

    fun toUserDto() = UserDto(...)
}