搭配Dagger2的做法

Example.java

public class RxBusExample {
    RxBus bus = RxBus.getInstance();
    bus.post();
}

RxBus+Dagger.java

@Singleton
public class RxBus {

    @Inject
    protected RxBus() {

    }

    private final Subject<Object, Object> busSubject = new SerializedSubject<>(PublishSubject.create());

    @NonNull
    public <T> Observable<T> subscribe(final Class<T> eventClass) {
        return busSubject.filter(e -> e.getClass().equals(eventClass))
                .map(o -> (T)o);
    }

    public void post(Object event) {
        busSubject.onNext(event);
    }
}

RxBus.java

public class RxBus {

    private static RxBus instance;
    
    public RxBus getInstance() {
        if (instance == null) {
            instance = new RxBus();
        }
        return instance;
    }
    
    protected RxBus() {

    }

    private final Subject<Object, Object> busSubject = new SerializedSubject<>(PublishSubject.create());

    @NonNull
    public <T> Observable<T> subscribe(final Class<T> eventClass) {
        return busSubject.filter(e -> e.getClass().equals(eventClass))
                .map(o -> (T)o);
    }

    public void post(Object event) {
        busSubject.onNext(event);
    }
}