Why does JSONFileToSave uses UUID as default key for a document instead of ObjectId?

[Alexey Sadovoy]

Hello. I just want to ask why JSONFileToSave class which is declared as

// Actually this is a helper object, not class, but this is not important
object JSONFileToSave {
 def apply[N](filename: N,
 contentType: Option[String] = None,
 uploadDate: Option[Long] = None,
 metadata: JsObject = Json.obj(),
 id: JsValue = Json.toJson(UUID.randomUUID().toString)) // <- This is what is mean
   (implicit naming: DefaultFileToSave.FileName[N]): JSONFileToSave = new JSONFileToSave(naming(filename), contentType, uploadDate, metadata, id)
}

Well, why it uses UUID as a default key instead of ObjectId? I've replaced it with newly generated ObjectId in my code, but I'm new to MongoDB and curious about such kind of decision

def save = SecuredAction.async(gridFSBodyParser(gridFS, (filename, contentType) =>
 JSONFileToSave(id = Json.toJson(BSONObjectID.generate)(BSONObjectIDFormat), // <- Replace default implementation
 filename = Some(filename), contentType = contentType))) { request =>
 
 request.body.files.headOption.map(_.ref.mapTo[JSONReadFile].map { meta =>
 log.debug(s"PDF $meta is saved successfully")
 Created[JsValue](SuccessResponse.build(request, Json.toJson(meta)(JSONReadFileWriter.writes)))
 }.recover {
  // Handling and logging
 }
}

I thought that default key should be ObjectId. At least it is preferred. Can you please explain why it is done is that way? Thanks

P.S. Play 2.3, ReactiveMongo 0.11

[Alexey Sadovoy]

Sorry for the grammar. It was written in rush

[cchantep]

Because there is no ObjectId type in JSON.

[Alexey Sadovoy]

Under ObjectId I mean hexadeciamal identifier like "507f191e810c19729de860ea"

суббота, 7 мая 2016 г., 15:06:04 UTC+3 пользователь cchantep написал:

[Cédric Chantepie]

The only requirement for GridFS is to provide unique ID, so there is no reason not to use UUID String which available in any JVM.