I'm using Play framework with Scala and Reactive Mongo to save an object into my mongodb database. Following this http://reactivemongo.org/releases/0.10/documentation/bson/usage.html I came up with the following code:
import java.util.Date
import com.google.inject.Inject
import model.User
import play.modules.reactivemongo.ReactiveMongoApi
import play.modules.reactivemongo.json.collection.JSONCollection
import reactivemongo.bson.{BSONDocument, BSONDocumentReader, BSONDocumentWriter, BSONObjectID}
import play.modules.reactivemongo.json._, ImplicitBSONHandlers._
import json.JsonFormatters._
class UserRepository @Inject() (val reactiveMongoApi : ReactiveMongoApi) {
private def users = reactiveMongoApi.db.collection[JSONCollection]("users")
def save(user: User) = {
users.insert(user)
}
implicit object UserWriter extends BSONDocumentWriter[User] {
def write(user: User) = {
BSONDocument(
"_id" -> Option(user.id).getOrElse(BSONObjectID.generate),
"name" -> user.name,
"email" -> user.email,
"companyName" -> user.companyName,
"created" -> Option(user.created).getOrElse(new Date)
)
}
}
implicit object UserReader extends BSONDocumentReader[User] {
def read(doc: BSONDocument): User = {
User(
doc.getAs[BSONObjectID]("_id").get,
doc.getAs[String]("name").get,
doc.getAs[String]("email").get,
doc.getAs[String]("companyName").get,
doc.getAs[Date]("created").get
)
}
}
}
I created my implicit writers to convert to a BsonDocument, so I was expecting it to be properly converted and saved into the database.
However, when I compile, I get:
UserRepository.scala:18: No Json serializer as JsObject found for type model.User. Try to implement an implicit OWrites or OFormat for this type.
[error] Error occurred in an application involving default arguments.
[error] users.insert(user)
I'm importing necessary packages as mentioned in No Json serializer as JsObject found for type play.api.libs.json.JsObject. I'm also importing json.JsonFormatters._ which includes:
implicit val userWrites : Format[User] = Json.format[User]
Yet, it's still returning the same error telling me it can't convert from JsObject to User. I fail to see where is the JsObject here, considering my User entity is just a case class with 5 fields.
case class User(var id: BSONObjectID, var name: String, var email: String, var companyName: String, var created: Date) {
}
Any ideas? What am I missing?
You are using BSONObjectID, and you do not have implicit OFormat for that type. Try this:
implicit val format = Json.format[User]
implicit val userFormats = new OFormat[User] {
override def reads(json: JsValue): JsResult[User] = format.reads(json)
override def writes(o: User): JsObject = format.writes(o).asInstanceOf[JsObject]
}
Typically, BSONObjectID (_id) does not make any sense in the application. Therefore, you should not use it. If you need an Id, for example as a running number, for users, you can define a new field. This is an example: https://github.com/luongbalinh/play-mongo/blob/master/app/models/User.scala