问题:

I have this data class in Kotlin (example):

import com.google.firebase.database.Exclude

data class User(val name: String = "", @Exclude val age: Int = 0)

And I don't want to save the age property in firebase. @Exclude should do this but it does not work, age is still saved.

Are there any workarounds?

回答1:

Placing @Exclude on a property targets its generated field and not its generated get accesor method. To do the latter you'll need to prefix "Exclude" with "get:". e.g.:

data class User(val name: String = "", @get:Exclude val age: Int = 0)

See Annotation Use-site Targets for more details.

回答2:

Actually you don't need to add only @get:Exclude but you need all 3 Exclude,

@Exclude @set:Exclude @get:Exclude.

I did it for imageUrl and providerId

data class FirebaseChatModel(
        @get:PropertyName("message")
        @set:PropertyName("message")
        var message: String = "",
        @get:PropertyName("type")
        @set:PropertyName("type")
        var type: Int = 1,
        @get:PropertyName("senderId")
        @set:PropertyName("senderId")
        var senderId: Int = 0,
        @get:PropertyName("receiverId")
        @set:PropertyName("receiverId")
        var receiverId: Int = 0,
        @Exclude @set:Exclude @get:Exclude var imageUrl: String? = "",
        @Exclude @set:Exclude @get:Exclude var providerId: Int = 0
)