No Json serializer as JsObject found for type play.api.libs.json.JsObject
I have the following code that works in a console app when referencing "org.reactivemongo" %% "play2-reactivemongo" % "0.10.5.0.akka23"
when I update the reference to "org.reactivemongo" % "play2-reactivemongo_2.11" % "0.11.0.play23-M3"
I get:
No Json serializer as JsObject found for type play.api.libs.json.JsObject. Try to implement an implicit OWrites or OFormat for this type.
import org.joda.time.DateTime
import reactivemongo.bson.BSONObjectID
import play.modules.reactivemongo.json.BSONFormats._
case class GoogleToken
(
id: Option[BSONObjectID],
name: String,
emailAddress: String,
refreshToken: String,
expires: DateTime
)
object GoogleToken {
import play.api.libs.json.Json
// Generates Writes and Reads
implicit val googleTokenFormat = Json.format[GoogleToken]
}
and then
val collection = db.collectionJSONCollection
val query = Json.obj()
val cursor = collection.find(query).
cursor[GoogleToken](ReadPreference.nearest).
collect[List]()
What am I doing wrong?
Solution 1:
The final release of ReactiveMongo 0.11 has been published ("org.reactivemongo" %% "play2-reactivemongo" % "0.11.0.play23"
).
As indicated on the updated documentation, for the default BSON/JSON conversions, it's recommended to have: import play.modules.reactivemongo.json._, ImplicitBSONHandlers._
.
Solution 2:
In my case, I was feeding ReactiveMongo (insert
) with a JsValue
instead than a JsObject
. In order to fix it, behind adding import play.modules.reactivemongo.json._
, I also had to change my implicit Writes
in OWrites
:
from
implicit val myWrites: Writes[A] = new Writes[A] {
def writes(a: A) = Json.obj(...)
to
implicit val myWrites: OWrites[A] = new OWrites[A] { <-- NOTE THE 'O' before 'Writes'
def writes(a: A) = Json.obj(...)
Solution 3:
Mine worked out after adding: import play.modules.reactivemongo.json._ import play.modules.reactivemongo.json.collection._
Solution 4:
try to add
import reactivemongo.play.json._