MongoDB和Spark：无法将STRING转换为TimestampType

我正在使用官方MongoDB Spark Connector从MongoDB集合中读取Spark中的数据，其代码如下：

val spark = SparkSession.

        builder().
        appName("MongoDB to SQL").
        getOrCreate()

val df = MongoSpark.load(spark, readConfig)
df.count()
readConfig是MongoDB的标准读配置，它工作正常。我遇到的问题是我从MongoDB获得一些日期/时间为String，它无法将其转换为Spark类型TimestampValue：

INFO DAGScheduler: Job 1 failed: count at transfer.scala:159, took 3,138191 s
Exception in thread "main" org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 1.0 failed 1 times, most recent failure: Lost task 0.0 in stage 1.0 (TID 1, localhost, executor driver):
com.mongodb.spark.exceptions.MongoTypeConversionException: Cannot cast STRING into a TimestampType (value: BsonString{value='2999.12.31 14:09:34'})
at com.mongodb.spark.sql.MapFunctions$.com$mongodb$spark$sql$MapFunctions$$convertToDataType(MapFunctions.scala:200)
at com.mongodb.spark.sql.MapFunctions$$anonfun$3.apply(MapFunctions.scala:39)
at com.mongodb.spark.sql.MapFunctions$$anonfun$3.apply(MapFunctions.scala:37)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
从我在调用df.printSchema()之前看到的.count()有问题的属性被列为

| | | |-- endDate: string (nullable = true)
在MongoDB中，endDate也存储为String。Spark是否在此处执行额外步骤来检测架构？然后它没有投出它......？从https://github.com/mongodb/mongo-spark/blob/master/src/main/scala/com/mongodb/spark/sql/MapFunctions.scala#L181查看源代码，它只进行简单的映射，

使用的版本：Mongo-Scala-Driver 2.4.0，Mongo-Spark-Connector 2.3.0，Spark 2.3.1