How cancel task with retrofit and rxjava

You can use the standard RxJava2 cancelling mechanism Disposable.

Observable<String> o = retrofit.getObservable(..);
Disposable d = o.subscribe(...);

// later when not needed
d.dispose();

Retrofit RxJava call adapter will redirect this to okHttp's cancel.

RxJava1: https://github.com/square/retrofit/blob/46dc939a0dfb470b3f52edc88552f6f7ebb49f42/retrofit-adapters/rxjava/src/main/java/retrofit2/adapter/rxjava/CallArbiter.java#L50-L53

RxJava2: https://github.com/square/retrofit/blob/46dc939a0dfb470b3f52edc88552f6f7ebb49f42/retrofit-adapters/rxjava2/src/main/java/retrofit2/adapter/rxjava2/CallEnqueueObservable.java#L92-L95

The chosen answer is for Rx Java 1 and is not valid for RxJava2. For the latter, you can use Disposable. Follow this:

1. Define CompositeDisposable compositeDisposable=new CompositeDisposable() as a field in your Activity or Fragment in class.

2. Define the api using Retrofit 2 as something like this:

   public Observable<YourPojo> callApiWithRetrofit() {
       return getService(YourApiService.class).callApi();
   }
   

3. Define Disposableand add it to the compositeDisposable instance:

   Disposable disposable = callApiWithRetrofit().subscribeOn(Schedulers.io()).observeOn(
           AndroidSchedulers.mainThread()).subscribeWith(
           new DisposableObserver<List<YourPojo>>() {
               @Override
               protected void onStart() {
                   super.onStart();
               }
   
               @Override
               public void onNext(@NonNull List<AlertAssetDTO> listResponse) {
   
               }
   
               @Override
               public void onError(@NonNull Throwable e) {
   
               }
   
               @Override
               public void onComplete() {
   
               }
           });
   mCompositeDisposable.add(disposable);
   

4. Wherever you want the connection to be cancelled (e.g. onDestroy() method of your Activity or onDestroyView() of your Fragment) call mCompositeDisposable.clear();

Multiple disposables may be added to the CompostieDisposable above this way.