在Kotlin/Native中用kotlinx.serialization进行多态反序列化

Question

我想使用Kotlin多平台项目中的kotlinx.serialization来解码包含多态类结构中对象列表的json字符串，但是它只在JVM上工作，而不是在本机上工作。下面是一个最低可重现性的例子：

@Serializable
abstract class Project {
    abstract val name: String
}

@Serializable
@SerialName("BasicProject")
data class BasicProject(override val name: String): Project()

@Serializable
@SerialName("OwnedProject")
data class OwnedProject(override val name: String, val owner: String) : Project()

fun main() {
    val data = Json.decodeFromString<List<Project>>("""
        [
            {"type":"BasicProject","name":"example"},
            {"type":"OwnedProject","name":"kotlinx.serialization","owner":"kotlin"} 
        ]
    """))
}  

这在JVM上有效，但在本机上引发以下异常：

kotlinx.serialization.SerializationException: Serializer for class ‘Project’ is not found.
Mark the class as @Serializable or provide the serializer explicitly.
On Kotlin/Native explicitly declared serializer should be used for interfaces and enums without @Serializable annotation.message

这个问题以前曾在编码的背景下讨论过，并提出了一些解决办法，例如here，但我的问题是解码。有解决办法吗?还是我只需要实现我自己的json解析器？

Answer 1

您需要显式地传递相互尊重的序列化程序和serializersModule。

object ListOfProjectSerializer : KSerializer<List<Project>> by ListSerializer(Project.serializer())

val module = SerializersModule {
    polymorphic(Project::class) {
        subclass(BasicProject::class)
        subclass(OwnedProject::class)
    }
}

fun main() {
    val data = Json { serializersModule = module }.decodeFromString(
        ListOfProjectSerializer,
        """
        [
            {"type":"BasicProject","name":"example"},
            {"type":"OwnedProject","name":"kotlinx.serialization","owner":"kotlin"} 
        ]
        """
    )
}