Component A:
this.service.getDataA().subscribe(
data => console.log(data))


service:
getDataA() {
  param1
  return this.getData(param1)
}

getData() {
//first without JWT
  let sub = new Subject<Response>();
  this.http.get(param1)
  .subscribe(
   res => sub.next(res)
   err => {
   //401 without JWT so I call authService
   this.authServ.getDataWithToken().subscribe(
   data => sub.next(data)
)
return sub.asObservable()
}
)
}


authService:

getDataWithToken() {
 let sub = new Subject<Response>()
 this.getToken().subscribe(
  token=> {
  //reachable just once
  this.http.get(url, token
 .
 .
 .
 return sub.asObservable();
 }


getToken(url) {
 let sub = new Subject<string>();
 if (this.tokens[url])
  // with console.log reachable
  sub.next(this.tokens[url])
  else {
   this.http.get(newToken).subscribe(
   (data) => sub.next(data)
   )
   return sub.asObservable()
 }

}