question: @ Override protected void doGet ( HttpServletRequest request , HttpServletResponse response ) throws ServletException , IOException { String userId = getUserId ( request ) ; DatastoreUtils datastoreUtils = new DatastoreUtils ( userId ) ; printPage ( response , datastoreUtils . getUserLastRunMessage ( ) ) ; if ( ! datastoreUtils . hasUserEntity ( ) || datastoreUtils . hasUserQueryFailed ( ) ) { runQuery ( request , response , userId , datastoreUtils ) ; } }
target:  This servlet responds to a GET request with a stencil page that will be filled with a chart and a message by client-side javascript. Also, if no data exists in the datastore for the current user, it sends a query to retrieve it.