rx_new_thread.java

private CompositeSubscription composite;

// ...

@Override
protected void onCreate(Bundle savedInstanceState) {
	composite = new CompositeSubscription();
}
@Override
protected void onDestroy() {
	super.onDestroy();
	composite.unsubscribe();
}

// ...

Func0<Observable<String>> selSignin = new Func0<Observable<String>>() {
	@Override
	public Observable<String> call() {
		final String error = "no error";
		return Observable.just(error);
	}
};

Action1<String> sel = new Action1<String>() {
	@Override
	public void call(final String error) {
		if (error == null) {
		}
		else {
		}
	}
};

composite.clear();

Subscription sub =
Observable
	.defer(selSignin)
	.subscribeOn(Schedulers.newThread())
	.observeOn(AndroidSchedulers.mainThread())
	.subscribe(sel)
;
composite.add(sub);