playframework - Map data from a Scala Future -

i'm implementing task calling rest endpoint in play framework, here's code in service:

override def getaccesstoken(logindata: logindata): future[unit] = {     logger.info("get access token hat")     val accesstokenurl = // url called     logger.info(accesstokenurl)     ws       .url(accesstokenurl)       .withhttpheaders(         headernames.accept -> contenttypes.json,         "username" -> logindata.username,         "password" -> logindata.password       )       .withrequesttimeout(timeout)       .get()       .map {         response => response.status match {           case status.ok =>             val responseasjson = response.json             future.successful((responseasjson \ "accesstoken").as[string])            case _ =>             val message = (response.json \"message").asopt[string]             throw new generalbadrequestexception(message.get)         }        }   } 

the response of val accesstokenurl like:

{     "accesstoken": "some token",     "userid": "some user id" } 

then in controller, write function data service above:

  private def handleaccesstoken: logindata => future[result] = { logindata =>      requesthatservice.getaccesstoken(logindata).map (       response => ok(response)) recover {       case e =>         val errorjson: jsvalue = json.obj(           "status" -> "error",           "error" -> json.obj(             "code" -> "error",             "message" -> e.getmessage           )         )         badrequest(errorjson)     }   } 

what i'm struggling @ moment part response => ok(response)) in function handleaccesstoken, want include ok result return in controller response can not data out, accesstoken, when i'm trying compile code , error throw this:

cannot write instance of unit http response. try define writeable[unit]

edit : @frederic answer, have problem here, how can attach response string jsvalue , pass ok result, thing

  val successjson: jsvalue = json.obj("status" -> "ok")     requesthatservice.getaccesstoken(logindata).map (       response =>              // code attach response successjson here              ok(successjson)) recover {                  ......             } 

the problem in definition of: def getaccesstoken(logindata: logindata): future[unit]

it should be: def getaccesstoken(logindata: logindata): future[string]

do need more explanations?