android - It's possible to download only one Json with retrofit2 for time? -

i'm using code download list of airports:

 final retrofit retrofit = new retrofit.builder()             .addconverterfactory(gsonconverterfactory.create())             .addcalladapterfactory(rxjavacalladapterfactory.create())             .baseurl(airportservice.service_endpoint).build();       airportservice service = retrofit.create(airportservice.class);      service.getairport()             .subscribeon(schedulers.newthread())             .observeon(androidschedulers.mainthread())             .subscribe(new subscriber<list<airport>>()             {                 @override                 public void oncompleted()                 {                  }                  @override                 public void onerror(throwable e)                 {                     e.printstacktrace();                 }                  @override                 public void onnext(list<airport> airports)                 {                     airps = airports;                 }             }); 

with interface:

@get("airports.json")   observable<list<airport>> getairport(); 

i want know if it's possible have in onnext() method airport , not list . i'll try i've got error (because airports 40k) , if it's possible add progress bar show download.

thank answers.