Using static methods/structures to pass data between activities

Issue

If I want to pass data between activities in the same application, a) I can use an Intent or b) use a database (passing the id in the Intent instead of the full data.
But I could also use c) a class with static data structures that both activities can access in a store/fetch fashion.
What are the cons of using (c) if I don't care about persistence of the data on app restart?

Solution

The big cons is that the Android OS can kill your process at any time. When the process will be re-created, Android will re-create all of your activities restoring their state.

Since Android doesn't know about how your static data should be handled, you will lose it and Activity B will be in an inconsistent state.

I'll make an example to be clearer:

1. Activity A is launched
2. A button on Activity A is clicked
3. Static data structures are being populated before launching Activity B
4. Activity B is launched and can access the static data
5. Android OS kills automatically your process
6. Activity A and Activity B are restored
7. The static data structures are not populated since they would have been populated when the button on Activity A is clicked
8. Activity B is in an inconsistent state

Answered By - Giorgio Antonioli