Kotlin - 无法序列化多态 类。找不到序列化程序

Question

我正在尝试使用 kotlinx.serialization 和 kotlin/native 序列化多态 类。我正在使用序列化指南中提供的示例：

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

val format = Json { serializersModule = module }

@Serializable
abstract class Project {
    abstract val name: String
}
            
@Serializable
@SerialName("owned")
class OwnedProject(override val name: String, val owner: String) : Project()

fun main() {
    val data: Project = OwnedProject("kotlinx.coroutines", "kotlin")
    println(format.encodeToString(data))
} 

此代码在 运行 与 JVM 一起工作时有效，但在 运行 与 kotlin native for linuxX64 编译和 运行 时抛出错误：

Uncaught Kotlin exception: kotlinx.serialization.SerializationException: Serializer for class 'Project' is not found. Mark the class as @Serializable or provide the serializer explicitly.
    at kfun:kotlin.Throwable#<init>(kotlin.String?){} (0x294767)
    at kfun:kotlin.Exception#<init>(kotlin.String?){} (0x28ea25)
    at kfun:kotlin.RuntimeException#<init>(kotlin.String?){} (0x28e725)
    at kfun:kotlin.IllegalArgumentException#<init>(kotlin.String?){} (0x28e925)
    at kfun:kotlinx.serialization.SerializationException#<init>(kotlin.String?){} (0x350185)
    at kfun:kotlinx.serialization.internal#serializerNotRegistered@kotlin.reflect.KClass<*>(){}kotlin.Nothing (0x36fa0d)
    at kfun:kotlinx.serialization#serializer@kotlin.reflect.KClass<0:0>(){0§<kotlin.Any>}kotlinx.serialization.KSerializer<0:0> (0x3505c8)
    at kfun:kotlinx.serialization.serializer$serializerByKTypeImpl#internal (0x3512d2)
    at kfun:kotlinx.serialization#serializer(kotlin.reflect.KType){}kotlinx.serialization.KSerializer<kotlin.Any?> (0x3503c8)
    ...

我是不是理解错了，代码应该在两个平台上都能工作？ 如何让它在本机上运行？

Answer 1

我从 github issues 中了解到它的当前限制。

It is a current limitation that should be properly documented (cc @qwwdfsad ). Please try format.encodeToString(PolymorphicSerializer(Project::class), data). In case of sealed classes, it should work. If it doesnt, simply use format.encodeToString(Project.serializer(), data)

Answer 2

是的，这是当前的限制，您可以查看Polymorphism documentation here and you can track the issue #1077

Answer 3

您在定义为 SerializersModule 的子class 时错过了为 OwnedProject class 声明序列化程序。

val module = SerializersModule {
        polymorphic(Project::class) {
            subclass(OwnedProject::class, OwnedProject.serializer()) // add here OwnedProject class serializer
        }
    }