error getting files from gridfs - mongodb

Question

I'm trying to display images and files from gridfs. So I started with the save function and it's working well:
import javax.inject.Inject
import org.joda.time.DateTime
import scala.concurrent.Future
import play.api.Logger
import play.api.Play.current
import play.api.i18n.{ I18nSupport, MessagesApi }
import play.api.mvc.{ Action, Controller, Request }
import play.api.libs.concurrent.Execution.Implicits.defaultContext
import play.api.libs.json.{ Json, JsObject, JsString }
import reactivemongo.api.gridfs.{ GridFS, ReadFile }
import play.modules.reactivemongo.{
MongoController, ReactiveMongoApi, ReactiveMongoComponents
}
import play.modules.reactivemongo.json._, ImplicitBSONHandlers._
import play.modules.reactivemongo.json.collection._
class griidfs #Inject() (
val messagesApi: MessagesApi,
val reactiveMongoApi: ReactiveMongoApi)
extends Controller with MongoController with ReactiveMongoComponents {
import java.util.UUID
import MongoController.readFileReads
type JSONReadFile = ReadFile[JSONSerializationPack.type, JsString]
// get the collection 'articles'
// a GridFS store named 'attachments'
//val gridFS = GridFS(db, "attachments")
private val gridFS = reactiveMongoApi.gridFS
// let's build an index on our gridfs chunks collection if none
gridFS.ensureIndex().onComplete {
case index =>
Logger.info(s"Checked index, result is $index")
}
def saveAttachment =
Action.async(gridFSBodyParser(gridFS)) { request =>
// here is the future file!
val futureFile = request.body.files.head.ref
futureFile.onFailure {
case err => err.printStackTrace()
}
// when the upload is complete, we add the article id to the file entry (in order to find the attachments of the article)
val futureUpdate = for {
file <- { println("_0"); futureFile }
// here, the file is completely uploaded, so it is time to update the article
updateResult <- {
println("_1"); futureFile
}
} yield updateResult
futureUpdate.map { _ =>
Redirect(routes.Application.index())
}.recover {
case e => InternalServerError(e.getMessage())
}
}
but when I try to get files from gridfs to display them in my browser with this code:
import reactivemongo.api.gridfs.Implicits.DefaultReadFileReader
def getAttachment = Action.async { request =>
// find the matching attachment, if any, and streams it to the client
val file = gridFS.find[JsObject, JSONReadFile](Json.obj("_id" -> id))
request.getQueryString("inline") match {
case Some("true") =>
serve[JsString, JSONReadFile](gridFS)(file, CONTENT_DISPOSITION_INLINE)
case _ => serve[JsString, JSONReadFile](gridFS)(file)
}
}
I get this error:
type arguments [play.api.libs.json.JsObject,griidfs.this.JSONReadFile]
do not conform to method find's type parameter bounds
[S,T <:
reactivemongo.api.gridfs.ReadFile[reactivemongo.play.json.JSONSerializationPack.type, _]]
in this line:
val file = gridFS.find[JsObject, JSONReadFile](Json.obj("_id" -> id))
Any help please?

Answer 1

I have been battling the same issue most of the day and finally have it up and running. I think it has something to do with the imports I will check in my work then begin to remove them one by one to check which one causes the issue. In the meantime here is a list of my imports. Hope this helps
import javax.inject.Inject
import forms._
import models._
import org.joda.time.DateTime
import play.modules.reactivemongo.json.JSONSerializationPack
import services._
import play.api.data._
import play.api.data.Forms._
import scala.async.Async._
import play.api.i18n.{ I18nSupport, MessagesApi }
import play.api.mvc.{ Action, Controller, Request }
import play.api.libs.json.{ Json, JsObject, JsString }
import reactivemongo.api.gridfs.{ GridFS, ReadFile }
import play.modules.reactivemongo.{
MongoController, ReactiveMongoApi, ReactiveMongoComponents
}
import play.api.libs.concurrent.Execution.Implicits.defaultContext
import scala.concurrent.Future
import play.modules.reactivemongo.json._
import com.mohiva.play.silhouette.api.{ Environment, LogoutEvent, Silhouette }
import com.mohiva.play.silhouette.impl.authenticators.CookieAuthenticator
import com.mohiva.play.silhouette.impl.providers.SocialProviderRegistry
import MongoController._
Edit Answer:
I have narrowed it down to this one: "import MongoController._"
add it and you should be ok :)