Spray JSON Support with Jackson

JacksonJsonSupport.scala

import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.module.scala.DefaultScalaModule
import com.fasterxml.jackson.module.scala.experimental.ScalaObjectMapper
import spray.http.{ContentTypes, HttpCharsets, HttpEntity, MediaTypes}
import spray.httpx.marshalling.Marshaller
import spray.httpx.unmarshalling.Unmarshaller

/**
 * Use Jackson directly to avoid json4s's dependencies
 */
trait JacksonJsonSupport {

  val jacksonModules = Seq(DefaultScalaModule)

  val mapper = new ObjectMapper() with ScalaObjectMapper
  mapper.registerModules(jacksonModules:_*)

  implicit def jacksonJsonUnmarshaller[T : Manifest] =
    Unmarshaller[T](MediaTypes.`application/json`) {
      case x: HttpEntity.NonEmpty =>
        val jsonSource = x.asString(defaultCharset = HttpCharsets.`UTF-8`)
        mapper.readValue[T](jsonSource)
    }

  implicit def jacksonJsonMarshaller[T <: Any] =
    Marshaller.delegate[T, String](ContentTypes.`application/json`)(mapper.writeValueAsString(_))

}