json4s customized serialization

fromScalaConsole.scala

import java.util.Date
import org.json4s._
import native.JsonMethods._
import org.json4s.native.Serialization


val body = """{
             |"_id": "1223456a171",
             |"siteid": "abc",
             |"serverid": "3266",
             |"weekOfYear": 2014001,
             |"extno": "6210",
             |"startTime": "\/Date(1399598421)\/",
             |"endTime": "\/Date(1399598601)\/"
             |}"""

case class RecIndex(id: String, siteId: String, serverId: String, weekOfYear: BigInt, extNo: String, startTime: Date, endTime: Date)

val DateTimeExtractor = """\/Date\((\d+)\)\/""".r
def convert(jsonStr: String): Date = jsonStr match {
  case DateTimeExtractor(time) => new Date(time.toLong)
}

val recIndexFormat: Formats => (PartialFunction[JValue, RecIndex], PartialFunction[Any, JValue]) = { format: Formats =>
  val reader: PartialFunction[JValue, RecIndex] = {
    case JObject(JField("_id", JString(id)) ::
                 JField("siteid", JString(siteId)) ::
                 JField("serverid", JString(serverId)) ::
                 JField("weekOfYear", JInt(weekOfYear)) ::
                 JField("extno", JString(extNo)) ::
                 JField("startTime", JString(startTime)) ::
                 JField("endTime", JString(endTime)) :: Nil) =>
      RecIndex(id, siteId, serverId, weekOfYear, extNo, convert(startTime), convert(endTime))
  }
  val writer: PartialFunction[Any, JValue] = {
    case r: RecIndex => JObject(
      JField("_id", JString(r.id)),
      JField("siteid", JString(r.siteId)),
      JField("serverid", JString(r.serverId)),
      JField("weekOfYear", JInt(r.weekOfYear)),
      JField("extno", JString(r.extNo)),
      JField("startTime", JString( s"""\/Date(${r.startTime.getTime})\/""")),
      JField("endTime", JString( s"""\/Date(${r.endTime.getTime})\/"""))
    )
  }
  (reader, writer)
}

class RecIndexFormat extends CustomSerializer[RecIndex](recIndexFormat)

implicit val formats = Serialization.formats(NoTypeHints) + new RecIndexFormat
parse(body.stripMargin).extract[RecIndex]