Play2.0ではsession.getIDがないよ

gistfile1.scala

package controllers

import play.api._
import play.api.mvc._
import play.libs
import java.util.UUID;
import play.cache.Cache

object Application extends Controller {
  
  def index = Action {implicit  request =>
    
    val ID_KEY = "___ID"
    var id =""
    if(request.session.data.contains(ID_KEY)){
        id = request.session.data(ID_KEY)
    }
    else{
        id = UUID.randomUUID().toString()
        // request.session.dataはimmutableなので、ここで追加は無理。考えなおしが必要
    	// request.session.data.updated(ID_KEY, id)
    }
    Cache.set(id + "-message", "test")
    Ok(views.html.index(id))
  }
  
}