How to watch the calling thread in java rx?

Question

anyway, to tell java rx to use the current thread in the observOn function? I am writing code for the syncadapter android and want the results to be observed in the sync adapter thread, and not in the main thread.

An example of a network call with Retrofit + RX Java looks something like this:

MyRetrofitApi.getInstance().getObjects() .subscribeOn(Schedulers.io()) .observeOn(<current_thread>) .subscribe(new Subscriber<Object>() { //do stuff on the sync adapter thread } 

I tried to use

 ... .observeOn(AndroidSchedulers.handlerThread(new Handler(Looper.myLooper()))) ... 

similar to how android rx creates a scheduler for the main thread, but it no longer works as soon as I submenu Looper.myLooper() for Looper.getMainLooper() .

I could use Schedulers.newThread (), but as a complex synchronization code with a lot of server calls, I would constantly create a new thread to start new network calls, which again create new threads to start more network calls. Is there any way to do this? Or is my approach completely wrong?

Answer 1

Try using Schedulers.immediate()

 MyRetrofitApi.getInstance().getObjects() .subscribeOn(Schedulers.io()) .observeOn(Schedulers.immediate()) .subscribe(new Subscriber<Object>() { //do stuff on the sync adapter thread } 

Its description says: Creates and returns a Scheduler that executes work immediately on the current thread.

Note:
I think it’s ok to work on the SyncAdapter thread, because it already uses a different thread

Answer 2

Oh, I just found this on the wiki: https://github.com/ReactiveX/RxAndroid#observing-on-arbitrary-threads

 new Thread(new Runnable() { @Override public void run() { final Handler handler = new Handler(); // bound to this thread Observable.just("one", "two", "three", "four", "five") .subscribeOn(Schedulers.newThread()) .observeOn(HandlerScheduler.from(handler)) .subscribe(/* an Observer */) // perform work, ... } }, "custom-thread-1").start(); 

I think this should work for your business too - besides creating a new topic, of course ... It's so simple:

 final Handler handler = new Handler(); // bound to this thread MyRetrofitApi.getInstance().getObjects() .subscribeOn(Schedulers.io()) .observeOn(HandlerScheduler.from(handler)) .subscribe(new Subscriber<Object>() { //do stuff on the sync adapter thread }