Creating an Object accessible by all Activities in Android

Question

I'm trying to create an ArrayList of Data containing Objects (Like a list of Addresses and properties (pretty complex)) and am wondering: How can I make an Object accessible (and editable) by all Activities and not just the one it was instanciated in?

Basically this:

1. Create Array in Activity 1
2. Access same Array in Activity 2 and 3
3. ???
4. Profit.

Answer 1

The easiest way to do this is by creating an Singleton. It's a kind of object that only can be created once, and if you try to access it again it will return the existing instance of the object. Inside this you can hold your array.

public class Singleton  {
    private static final Singleton instance = new Singleton();

    // Private constructor prevents instantiation from other classes
    private Singleton() {
    }

    public static Singleton getInstance() {
        return instance;
    }

}

Read more about singleton: http://en.wikipedia.org/wiki/Singleton_pattern