Java – Android Parcelable and objects are passed by reference

I have many objects, some of which have different ArrayList properties (custom objects). The same object may appear in any of these ArrrayList.

I

want to pass these objects by reference so that when I edit one of them, the change is reflected in all ArrayLists/objects.

I need to pass these objects or ArrayLists as parcelable to different activities. I think the Parcelable interface is causing passing by reference not to work (which makes sense considering you need to implement a new constructor, so let’s say a new object is created/cloned every time a parcel is created and passed?). )。

I would like to know what is the best way to deal with this situation, ie. How can I implement or simulate the behavior of an object passed by reference. I don’t really want to use any persistent storage technology if it can be avoided.

I

know it’s an old question, but since I’m here 🙂

Anyway, what I did was pass the ID of the item I wanted and then use Application to save my data.

For example, let’s say I have a class called Order and there are many such Line(s) for each order

class Order {
    UUID _id;
    List<Line> _lines = new ArrayList<>();
}

class Line {
    UUID _id;
    Product _product ;
    BigDecimal _price;
    int _quantity;
}

And so on

So I have an implementation of an application where I store all my (in memory) orders as follows:

public class App extends Application {
    public static final List<Order> Orders = new Order();

public static final Order GetOrder(UUID id) {
        for (Order o : Orders) {
            If(o.get_id(). Equals(id))
            return o;
        }
        return null;
    }
}

Then, if I want to go through a specific order, I do something like this:

Intent i = new Intent(this, OrderEdit.class);
i.putExtra(OrderEdit.ID, my_order.get_id(). ToString());
startActivity(i);

On the other side:

UUID id = UUID.fromString(getArguments().getExtra(ID));
App.GetOrder(id); 

This way you can always pass a reference.