How to make multiple request and wait until data is come from all the requests in retrofit 2.0 - android

Question

current code:

Retrofit retrofit = new Retrofit.Builder()
                  .baseUrl(Constant.BASEURL)
                  .addConverterFactory(GsonConverterFac         


        

Answer 1

If you don't mind adding one more dependency you could use RxAndroid. In particular, you should change your Service interface with something similar to this:

@GET("/data")
Observable getNewsData();

Now, you can do this:

Observable
            .range(0, **numberOfTimes**, Schedulers.newThread())
            .observeOn(AndroidSchedulers.mainThread())
            .doOnError(new Action1() {
                @Override
                public void call(Throwable throwable) {
                    Log.e("error", throwable.toString());
                }
            })
            .concatMap(new Func1>() {
                @Override
                public Observable call(Integer integer) {
                    Log.i("news", "nr:" + integer);
                    //Does the call.
                    return service.getNewsData(integer);
                }
            }).concatMap(new Func1>() {
        @Override
        public Observable call(final ResponsWrapper responsWrapper) {
            return Observable.fromCallable(new Func0() {
                @Override
                public News call() {
                    //change the result of the call to a news.
                    return new News(responsWrapper.category,responsWrapper.title,null);
                }
            });
        }
    }).toList().subscribe(new Action1>() {
        @Override
        public void call(List newList) {
           AdapterRecommendation adapter = new AdapterRecommendation(getApplicationContext(), newsList);
           listView.setAdapter(adapter);
        }
    });

Just change numberOfTimes and it will work! Hope it helps.

P.s. maybe there are cleaner ways to do this.