[英]BsonInvalidOperationException in ktor
Being new to MongoDB, I'm currently integrating the kMongo library to my ktor project, and trying to create a database to read & write event models to.作为 MongoDB 的新手,我目前正在将kMongo库集成到我的 ktor 项目中,并尝试创建一个数据库来读取和写入事件模型。
Following the instructions for object mapping in the kMongo user manual , I've created a mongoId
field which gets serialised as a String
named _id
.按照kMongo 用户手册中 object 映射的说明,我创建了一个mongoId
字段,它被序列化为一个名为_id
的String
。
My event model is a data class, nested in sealed classes but gets serialised correctly by KotlinX-Serialization.我的事件 model 是数据 class,嵌套在密封类中,但通过 KotlinX-Serialization 正确序列化。 The model looks as such: model 看起来是这样的:
sealed class Event {
@SerialName("_id") abstract val mongoId: String
abstract val id: ID.Event
abstract val dateTime: LocalDateTime
fun asString() = id.toString()
sealed class Hiring : Event() {
@SerialName("_id") abstract override val mongoId: String
abstract override val id: ID.Event
abstract override val dateTime: LocalDateTime
@Serializable
data class Start(
override val id: ID.Event,
override val dateTime: LocalDateTime,
val hiringDetailsId: ID.HiringDetails
) : Hiring() {
@SerialName("_id") override val mongoId: String = id.asString()
}
...
In a repository class, I initialise MongoDB and use the generic, parameter-less find()
on a collection to retrieve all Event
models from the database:在存储库 class 中,我初始化 MongoDB 并在集合上使用通用的无参数find()
从数据库中检索所有Event
模型:
...
private val kmongo = KMongo.createClient().coroutine.client
private val db = kmongo.getDatabase("test")
private val eventCollection = db.getCollection<Event>().coroutine
...
override suspend fun getAllEvents() = eventCollection.find().toList()
Then inside of the Main class, I try to load the Event
data on a click trigger:然后在 Main class 内部,我尝试在点击触发器上加载Event
数据:
...
val id = ID.Event(UUID())
...
it.on.click {
runBlocking {
val events = eventRepo.getAllEvents().toString()
logger.debug { events }
}
}
The strange part starts here, the server starts correctly and MongoDB is initialised correctly, but as soon as I try to do the read on the click trigger, I am presented with following error:奇怪的部分从这里开始,服务器正确启动并且 MongoDB 正确初始化,但是一旦我尝试在点击触发器上进行读取,我就会收到以下错误:
org.bson.BsonInvalidOperationException: readString can only be called when CurrentBSONType is STRING, not when CurrentBSONType is DOCUMENT.
at org.bson.AbstractBsonReader.verifyBSONType(AbstractBsonReader.java:689)
at org.bson.AbstractBsonReader.checkPreconditions(AbstractBsonReader.java:721)
at org.bson.AbstractBsonReader.readString(AbstractBsonReader.java:456)
at com.github.jershell.kbson.FlexibleDecoder.decodeString(BsonFlexibleDecoder.kt:130)
at kotlinx.serialization.encoding.AbstractDecoder.decodeStringElement(AbstractDecoder.kt:58)
at kotlinx.serialization.internal.AbstractPolymorphicSerializer.deserialize(AbstractPolymorphicSerializer.kt:52)
at kotlinx.serialization.encoding.Decoder$DefaultImpls.decodeSerializableValue(Decoding.kt:257)
at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:16)
at org.litote.kmongo.serialization.SerializationCodec.decode(SerializationCodec.kt:66)
at com.mongodb.internal.operation.CommandResultArrayCodec.decode(CommandResultArrayCodec.java:52)
at com.mongodb.internal.operation.CommandResultDocumentCodec.readValue(CommandResultDocumentCodec.java:60)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:87)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:42)
at org.bson.internal.LazyCodec.decode(LazyCodec.java:48)
at org.bson.codecs.BsonDocumentCodec.readValue(BsonDocumentCodec.java:104)
at com.mongodb.internal.operation.CommandResultDocumentCodec.readValue(CommandResultDocumentCodec.java:63)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:87)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:42)
at com.mongodb.internal.connection.ReplyMessage.<init>(ReplyMessage.java:51)
at com.mongodb.internal.connection.InternalStreamConnection.getCommandResult(InternalStreamConnection.java:535)
at com.mongodb.internal.connection.InternalStreamConnection.access$500(InternalStreamConnection.java:86)
at com.mongodb.internal.connection.InternalStreamConnection$2$1.onResult(InternalStreamConnection.java:520)
at com.mongodb.internal.connection.InternalStreamConnection$2$1.onResult(InternalStreamConnection.java:498)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback$MessageCallback.onResult(InternalStreamConnection.java:821)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback$MessageCallback.onResult(InternalStreamConnection.java:785)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:645)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:642)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:250)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:233)
at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:129)
at java.base/sun.nio.ch.Invoker.invokeDirect(Invoker.java:160)
at java.base/sun.nio.ch.UnixAsynchronousSocketChannelImpl.implRead(UnixAsynchronousSocketChannelImpl.java:573)
at java.base/sun.nio.ch.AsynchronousSocketChannelImpl.read(AsynchronousSocketChannelImpl.java:276)
at java.base/sun.nio.ch.AsynchronousSocketChannelImpl.read(AsynchronousSocketChannelImpl.java:297)
at com.mongodb.internal.connection.AsynchronousSocketChannelStream$AsynchronousSocketChannelAdapter.read(AsynchronousSocketChannelStream.java:144)
at com.mongodb.internal.connection.AsynchronousChannelStream.readAsync(AsynchronousChannelStream.java:118)
at com.mongodb.internal.connection.AsynchronousChannelStream.readAsync(AsynchronousChannelStream.java:107)
at com.mongodb.internal.connection.InternalStreamConnection.readAsync(InternalStreamConnection.java:642)
at com.mongodb.internal.connection.InternalStreamConnection.access$600(InternalStreamConnection.java:86)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback.onResult(InternalStreamConnection.java:775)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback.onResult(InternalStreamConnection.java:760)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:645)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:642)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:250)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:233)
at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:129)
at java.base/sun.nio.ch.UnixAsynchronousSocketChannelImpl.finishRead(UnixAsynchronousSocketChannelImpl.java:447)
at java.base/sun.nio.ch.UnixAsynchronousSocketChannelImpl.finish(UnixAsynchronousSocketChannelImpl.java:195)
at java.base/sun.nio.ch.UnixAsynchronousSocketChannelImpl.onEvent(UnixAsynchronousSocketChannelImpl.java:217)
at java.base/sun.nio.ch.KQueuePort$EventHandlerTask.run(KQueuePort.java:312)
at java.base/sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:113)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)
According to the stacktrace, something seems to go wrong in the BSON
filtering part, despite there being none.根据堆栈跟踪, BSON
过滤部分似乎有 go 错误,尽管没有。 When I use the MongoDB compass to validate the object inside of the database, I can see that everything is initialised and written perfectly fine:当我使用 MongoDB 指南针验证数据库内部的 object 时,我可以看到一切都已初始化并且写得非常好:
The normal id
field is used in my software internally as an ID.Event
object type whilst the _id
is used by Mongo
internally.正常的id
字段在我的软件内部用作ID.Event
object 类型,而_id
由Mongo
在内部使用。
Can someone point me to what the potential issue could be here?有人可以指出这里可能存在的潜在问题吗?
I'm not familiar with Kotlin, but I'd like to dive into this a bit further:我不熟悉 Kotlin,但我想更深入地了解一下:
If it wouldn't unwrap the second time, the Mongo Compass would likely reveal the
_id
orid
field to contain a bracket{
while these are currently mapped as expected (aString
for_id
and an object forid
).如果它不会第二次展开,Mongo Compass 可能会显示_id
或id
字段以包含括号{
而这些当前已按预期映射(String
用于_id
和 object 用于id
)。
To confirm, the current structure of your document is (eg here in the playground ):确认一下,您文档的当前结构是(例如在操场上):
{
_id: "7d51",
id: {
id: "7d51"
},
hiringDetailsId: {
id: "8392"
}
}
We can see that in your screenshot from Compass where the _id
field shows the value being the string directly whereas the other two fields show that the values are Objects (that each contain { id: "<string>" }
values).我们可以在 Compass 的屏幕截图中看到,其中_id
字段直接显示值是字符串,而其他两个字段显示值是对象(每个对象都包含{ id: "<string>" }
值)。
The error is specifically stating that the code is expecting a string but finding a document:该错误特别指出代码需要一个字符串但找到了一个文档:
BsonInvalidOperationException: readString can only be called when CurrentBSONType is STRING, not when CurrentBSONType is DOCUMENT.
I can't speak to the internal unpacking, but it really feels to me like the nested id.id
(and potentially also hiringDetailsId.id
) is the problem here.我不能谈论内部拆包,但我真的觉得嵌套的id.id
(也可能是hiringDetailsId.id
)是这里的问题。 Even if it isn't directly related, it would seem to be an opportunity to simplify the schema unless there is a compelling reason to introduce that extra level of nesting.即使它不直接相关,它似乎也是一个简化架构的机会,除非有令人信服的理由引入额外的嵌套级别。
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