Room Persistence: Error:Entities and Pojos must have a usable public constructor

Question

I\'m converting a project to Kotlin and I\'m trying to make my model (which is also my entity) a data class I intend to use Moshi to convert the JSON responses from the API<

Answer 1

https://issuetracker.google.com/issues/62851733

i found this is @Relation's projection bug! not Kotlin language problem. based google GithubBrowserSample java also happend error, but different error message.

below is my kotlin code:

data class UserWithCommunities(
        @Embedded
        var user: User = User(0, null),

        @Relation(parentColumn = "id",
                entityColumn = "users_id",
                entity = CommunityUsers::class,
                projection = arrayOf("communities_id")) // delete this line.
        var communityIds: List = emptyList()
)

right:

data class UserWithCommunities(
        @Embedded
        var user: User = User(0, null),

        @Relation(parentColumn = "id",
                entityColumn = "users_id",
                entity = CommunityUsers::class)
        var communityList: List = emptyList()
)