kotlinx.serialization.MissingFieldException:字段“X”是使用串行名称的类型所必需的，但它在kotlin中丢失了错误

Question

我正在制作一个字典应用程序，我在资产文件中有自己的json数据集。我第一次从这组数据中读取数据并将其保存到房间，然后再从这个房间读取其他时间的数据。但是，我遇到了这个错误。

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.enestigli.dictionaryapp, PID: 1868
    kotlinx.serialization.MissingFieldException: Field 'example' is required for type with serial name 'com.enestigli.dictionaryapp.data.locale.datamodel.Idioms', but it was missing
        at kotlinx.serialization.internal.PluginExceptionsKt.throwMissingFieldException(PluginExceptions.kt:20)
        at com.enestigli.dictionaryapp.data.locale.datamodel.Idioms.<init>(Idiom.kt:28)
        at com.enestigli.dictionaryapp.data.locale.datamodel.Idioms$$serializer.deserialize(Idiom.kt:28)
        at com.enestigli.dictionaryapp.data.locale.datamodel.Idioms$$serializer.deserialize(Idiom.kt:28)
        at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:59)
        at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:36)
        at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
        at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableElement(AbstractDecoder.kt:70)
        at kotlinx.serialization.encoding.CompositeDecoder$DefaultImpls.decodeSerializableElement$default(Decoding.kt:535)
        at kotlinx.serialization.internal.ListLikeSerializer.readElement(CollectionSerializers.kt:80)
        at kotlinx.serialization.internal.AbstractCollectionSerializer.readElement$default(CollectionSerializers.kt:51)
        at kotlinx.serialization.internal.AbstractCollectionSerializer.merge(CollectionSerializers.kt:36)
        at kotlinx.serialization.internal.AbstractCollectionSerializer.deserialize(CollectionSerializers.kt:43)
        at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:59)
        at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:36)
        at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
        at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableElement(AbstractDecoder.kt:70)
        at com.enestigli.dictionaryapp.data.locale.datamodel.IdiomItem$$serializer.deserialize(Idiom.kt:15)
        at com.enestigli.dictionaryapp.data.locale.datamodel.IdiomItem$$serializer.deserialize(Idiom.kt:15)
        at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:59)
        at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:36)
        at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
        at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableElement(AbstractDecoder.kt:70)
        at kotlinx.serialization.encoding.CompositeDecoder$DefaultImpls.decodeSerializableElement$default(Decoding.kt:535)
        at kotlinx.serialization.internal.ListLikeSerializer.readElement(CollectionSerializers.kt:80)
        at kotlinx.serialization.internal.AbstractCollectionSerializer.readElement$default(CollectionSerializers.kt:51)
        at kotlinx.serialization.internal.AbstractCollectionSerializer.merge(CollectionSerializers.kt:36)
        at kotlinx.serialization.internal.AbstractCollectionSerializer.deserialize(CollectionSerializers.kt:43)
        at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:59)
        at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:36)
        at com.enestigli.dictionaryapp.data.locale.datamodel.IdiomDataModel$$serializer.deserialize-zhuhEdE(Idiom.kt:8)
        at com.enestigli.dictionaryapp.data.locale.datamodel.IdiomDataModel$$serializer.deserialize(Idiom.kt:8)
        at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:59)
        at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:36)
        at kotlinx.serialization.json.Json.decodeFromString(Json.kt:100)
        at com.enestigli.dictionaryapp.data.locale.datasource.AssetDataSource.getIdioms-zhuhEdE(AssetsDataSource.kt:84)
E/AndroidRuntime:     at com.enestigli.dictionaryapp.data.repository.IdiomsRepositoryImpl.initData(IdiomsRepositoryImpl.kt:21)
        at com.enestigli.dictionaryapp.domain.use_case.idiom.insert.InsertIdiomsUseCase.initIdiomData(InsertIdiomsUseCase.kt:12)
        at com.enestigli.dictionaryapp.presentation.SplashScreen.SplashScreenViewModel$insertAllDataToRoomDb$1.invokeSuspend(SplashScreenViewModel.kt:38)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
        at android.os.Handler.handleCallback(Handler.java:942)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loopOnce(Looper.java:201)
        at android.os.Looper.loop(Looper.java:288)
        at android.app.ActivityThread.main(ActivityThread.java:7898)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)
        Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@5aeb15c, Dispatchers.Main.immediate]

我的json数据集看起来像这个

[
    {
        "letter": "A",
        "idioms": [
            {
                "idiom": "above board",
                "meaning": "If something is above board, it's been done in a legal and honest way.",
                "examples": [
                    "I'm sure the deal was completely above board as I know James well and he'd never do anything illegal or corrupt.",
                    "The minister claimed all the appointments were above board and denied claims that some positions had been given to his friends."
                ]
            },
            {
                "idiom": "above the law",
                "meaning": "If someone is above the law, they are not subject to the laws of a society.",
                "examples": [
                    "Just because his father is a rich and powerful man, he seems to think he's above the law and he can do whatever he likes.",
                    "In a democracy, no-one is above the law - not even a president or a prime-minister."
                ]
            },
            {
                "idiom": "Achilles' heel",
                "meaning": "An Achilles' heel is a weakness that could result in failure.",
                "examples": [
                    "He's a good golfer, but his Achilles' heel is his putting and it's often made him lose matches.",
                    "The country's dependence on imported oil could prove to be its Achilles' heel if prices keep on rising."
                ]
            },

我的数据模型

@JvmInline
@Serializable
value class IdiomDataModel(
    val allData: List<IdiomItem>
)


@Serializable
data class IdiomItem(
    val letter: String,
    val idioms: List<Idioms>
) {

    fun toEntity() = IdiomEntity(
        letter = letter,
        idioms = idioms
    )
}


@Serializable
data class Idioms(
    val idiom: String,
    val meaning: String,
    val example: List<String>
)

实体

@Entity(tableName = "idioms")
data class IdiomEntity(

    @ColumnInfo(name = "letter") val letter:String,
    @ColumnInfo(name = "idioms") val idioms:List<Idioms>,
    @PrimaryKey(autoGenerate = true) val uid:Int? = null


)

我认为val example: List<String>在Idioms data class是从这一部分。这可能与Json数据集中的example列表不完全匹配吗？

Answer 1

在习语数据类中，将示例重命名为示例，它应该可以工作。

旧：

@Serializable
data class Idioms(
    val idiom: String,
    val meaning: String,
    val example: List<String>
)

新的

@Serializable
    data class Idioms(
        val idiom: String,
        val meaning: String,
        val examples: List<String>
    )