Question

EDIT: Please ignore this question – I’ve managed to solve it in a way which works fine for what I need (see my own answer below).

I have a WeatherSpinner class which extends Spinner. The class shows region names which I originally did using an ArrayAdapter<String> but I now want to use ArrayAdapter<Locale>(Locale is an abstract ’empty’ class of my own).

I’m getting a ClassCastException when trying to populate my ArrayAdapter with the following…

protected ArrayList<?> theList;
protected ArrayAdapter<Locale> aa = null;
...
protected void updateContents(ArrayList<?> list, int selectedItem) {
    theList = list;
    // Exception thrown on next line
    aa = new ArrayAdapter<Locale>(theContext, android.R.layout.simple_spinner_item,
        (Locale[]) theList.toArray());
    ...

}

I’m passing a RegionList object into updateContents() as the ‘list’ parameter and RegionList extends ArrayList<Region>, and Region extends Locale. I’ve also overriden Region’s toString() method to return a valid String.

What am I not seeing here? Am I wrong about the way ArrayList<?>.toArray() works?

Answer 1

OK, solved.

I needed to use the toArray(T[] contents) method of ArrayList as follows…

Locale[] locArray = new Locale[theList.size()];
locArray = (Locale[]) theList.toArray(locArray);
aa = new ArrayAdapter<Locale>(theContext, android.R.layout.simple_spinner_item,
        locArray);