android - How to handle the flow when a Network Exception is thrown -

i built app , need handle network exceptions in many places. want know way it.

in activity have like:

oncreate {    ...    fetchdata(); // needs internet    processdata();    showdata(); } 

in fetchdata() method, might not fetch because there's no connectivity or poor signal. in case, show alertdialog , tell user there network issue, , when clicks ok try fetch again.

the problem thread run fetchdata(), build , show dialog, keep running processdata() , on. method fetchdata() called 2 different places in app, ideal stop thread until tries again , load data. logic can use here?

i know might simple question, i'm stuck on , don't know patterns apply. should propagate error , handle in calls fetchdata(), or there way stop thread until data loaded?

edit: fetchdata() is working , runs background thread downloads data, , wait finish return response or null. far, if there's error null , logs me network error. want know how handle , keep flow

just modify code this:

oncreate {    ...     asynctask task = new asynctask()      {              @override             protected object doinbackground(object[] objects)             {                  try{                      fetchdata();} catch(exception e) {e.printstacktrace();}             }      }              processdata();             showdata();     }