How do I get a Date to store as a Date in MongoDB instead of an Int64?

I'm using the new MongoDB Scala Driver. When I store a java.util.Date, it is being stored in MongoDB as an Int64 instead of a MongoDB Date. I have some code that looks like this:

implicit val writer = new Writes[Forecast] {
  def writes(x: Forecast): JsValue = {
    Json.obj(
      // ...
      "issueDateTime" -> x.issueDateTime // which is a java.util.Date
      // ...
    )
  }
}

but what ends up in MongoDB is an Int64, not a Date. How do I get a Date into MongoDB?

If you are using the latest MongoDB Scala Driver v1.1. Instead of using the Json.obj to build your document, try using Document class.

The BsonTransformer will transform java.util.Date to BsonDateTime

For example:

val newdate = new Date()
val doc: Document = Document("test" -> newdate)
collection.insertOne(doc).results()

Will result in :

{  "_id" : ObjectId("56665bf619a63d9e538b2851"), 
    "test" : ISODate("2015-12-08T04:26:29.999Z") 
}

Hope that helps.