Handle empty response with retrofit and rxjava 2.x

Question

When using rxjava 1.x i used to return Observable<Void> to handle empty response from retrofit:

@POST( "login" ) Observable<Void> getToken( @Header( "Authorization" ) String authorization,                                        @Header( "username" ) String username,                                        @Header( "password" ) String password ); 

But since rxjava 2.x won't emit anything with Void is there any good practice to handle those empty responses?

Answer 1

Completable was designed for such cases. It available since RxJava 1.1.1. From the official docs:

Represents a deferred computation without any value but only indication for completion or exception. The class follows a similar event pattern as Reactive-Streams: onSubscribe (onError|onComplete)?

So just change your method's return type:

@POST("login") Completable getToken(@Header("Authorization") String authorization,                      @Header("username")      String username,                      @Header("password")      String password); 

And rewrite your subscriber, e.g.:

apiManager.getToken(auth, name, pass)     ...     .subscribe(() -> {         //success     }, exception -> {         //error     }); 

Answer 2

Another solution is:

@POST("login") Observable<Response<Void>> getToken(@Header("Authorization") String authorization,                                     @Header("username") String username,                                     @Header("password") String password); 

Update: But I would rather use Completable