package com.layer_net.rxandroidex;

import rx.Observable;
import rx.subjects.PublishSubject;
import rx.subjects.SerializedSubject;
import rx.subjects.Subject;

/**
 * Created by layer on 19/1/2559.
 */
public class RxEventBus {
    private final Subject<Object, Object> bus = new SerializedSubject<>(PublishSubject.create());

    public void post(Object o) {
        bus.onNext(o);
    }

    public Observable<Object> getBusObservable() {
        return bus;
    }
}

package com.layer_net.rxandroidex;

import rx.Observable;
import rx.subjects.PublishSubject;
import rx.subjects.SerializedSubject;
import rx.subjects.Subject;

/**
 * Created by nuuneoi on 1/19/2016.
 */
public class RxEventBus {
    private final Subject<Object, Object> bus = new SerializedSubject<>(PublishSubject.create());

    public void post(Object o) {
        bus.onNext(o);
    }

    public Observable<Object> getBusObservable() {
        return bus;
    }
}

Update RxEventBus.java