How to share a java object reference between android components

Question

Lately I've read this comment on Reddit:

I think EventBus on android is popular because people don't know how to share a java object reference between android components like a Fragment and an Activity, or 2 Activities and so on. So basically I think people don't know how 2 Activites can observe the same object for data changes which I think comes from the fact that we still don't know how to architect our apps properly.

As far as I know:

• directly reference values

  ((HostActivity)getActivity()).someValue

  may cause problem such as memory leaks or NullPointerException

• Callbacks or other observer pattern

  EventBus,inner class like listener and etc

So I was curious that whether there is any other ways , could you share with me on it?

Answer 1

imo, there are few ways out of your opinion such as:

• use local db, now ORM like Realm is really popular, its also safe way.
• use share preferences if your object is able to convert to json, its up to your situation.
• use intent with serialize/parcelable object bundle.
• use a singleton, now @scope with Dagger 2 is good choice.
• use RxJava as event bus.