mongoからcollection.findで取ってきたデータはtoListしないとListにならないのわかってなかった

gistfile1.scala

package jp.ddo.loveless

import com.mongodb.casbah.Imports._
import net.liftweb.json._

object CasbahSample extends App {
  val collection = MongoConnection("servername")("tumblr")("reblogdata")
  val condition = MongoDBObject("count"->221)

  case class Data(rk:String, count:Int)

  val list = collection.find(condition).map{ x =>
    val rk = x.getAs[String]("rk").getOrElse("no")
    val count = x.getAs[Int]("count").getOrElse(0)
    Data(rk, count)
  }.toList

  implicit val format = Serialization.formats(NoTypeHints)
  val json = Serialization.write(list)

  println(json)
}