My web application developed using (GWT/J2EE stack) is deployed on Payara glassfish server and its on production server. We frequently stops the server for maintenance like 'fixing bugs/for enhancement/upgrading'. If the end user try to access the web application and server is down it shows
"This site can’t be reached"
Is it possible to show the Custom message like Server is down for maintenance to end user? any thoughts/suggestion on this.