pubulic static String getRequestPrefix(HttpServletRequest request){

           //獲取網路協議

            String networkProtocol = request.getScheme();

            //網路IP

            String ip = request.getServerName();

            //埠號

            int port = request.getServerPort();

            //專案釋出路徑

            String webApp = request.getContextPath();

            String urlPrefix = networkProtocol+"://"+ip+":"+port+webApp;

            return urlPrefix;

}