类序列化器“.”找不到。ktor + kotlinx.serialization

Question

我使用的是ktor + kotlinx.serialization，我希望实现call.respond(Respond("some mesage",null))的json响应，如下所示：

result = null时的

{ "message" : "some mesage" }

result is any Type时的

{ 
"message" : "some mesage",
"result" : "showing result"
}

or

{ 
"message" : "some mesage",
"result" : 0.0
}

• my响应数据类

@kotlinx.serialization.Serializable
data class Respond<T>(

   @SerialName("message")
   val message : String? = null,

   @SerialName("result")
   val result : T? = null
)

但它让我犯了这样的错误：

Serializer for class 'Respond' is not found.
Mark the class as @Serializable or provide the serializer explicitly.

Answer 1

我通过创建BaseResponse的继承，然后使用可空字符串覆盖结果类型的多态响应实现了：

@kotlinx.serialization.Serializable
sealed class BaseResponse<T> {
    abstract val message: String?
    abstract val result: T?
}

@kotlinx.serialization.Serializable
@SerialName("Response")
class Response(
    @SerialName("message") override val message: String?, override val result: String? = null
) : BaseResponse<String>()

@kotlinx.serialization.Serializable
@SerialName("FullResponse")
class FullBaseResponse<T>(
    @SerialName("message") override val message: String?, override val result: T
) : BaseResponse<T>()

val responseModule = SerializersModule {
    polymorphic(BaseResponse::class) {
        subclass(Response.serializer())
        subclass(FullBaseResponse.serializer(PolymorphicSerializer(Any::class)))
    }
}

并添加了json配置：

install(ContentNegotiation) {
        json(Json {
            explicitNulls = false
            serializersModule = responseModule
        })
    }

所以当我只想显示消息时，我只使用call.respond(Respond("some message"))