BlockingGetExample.java

 // Calling function, This is in Activity or Viewmodel
 public void blockingGetExample() {
    
   BoredActivitiesAPI sampleAPI = getRetrofitInstance.create(BoredActivitiesAPI.class);
   // Eventhough RxJava call is happening in diffrent thread, Result of the RxJava will be strored in 
   // `s` and nexr line is executed. 
   String s = sampleAPI.getSingleResponse()
                .onErrorReturn(new Function<Throwable, BoredActivities>() {
                    @Override
                    public BoredActivities apply(Throwable throwable) throws Exception {
                        BoredActivities boredActivities = new BoredActivities();
                        boredActivities.setLink("");
                        return boredActivities;
                    }
                })
                .map(new Function<BoredActivities, String>() {
                    @Override
                    public String apply(BoredActivities boredActivities) throws Exception {
                        return boredActivities.getLink();
                    }
                })
                .subscribeOn(Schedulers.io()).blockingGet();

        Log.d("Sample", "blockingGetExample: "+s);
    }

// Retrofit Method, interface, name - BoredActivitiesAPI.java

    @GET("activity")
    Single<BoredActivities> getSingleResponse();