Question

I have the following code:

Widget[] widgetArray = widgetService.getAllWidgets();
List<Widget> widgets = Arrays.asList(widgetArray);

// Prune out any Widgets named "Melvin".
Iterator<Widget> iter = widgets.iterator();
while(iter.hasNext()) {
    Widget w = iter.next();

    if("Melvin".equals(w.getName()))
        iter.remove();
}

When I run this code I get a runtime java.lang.UnsupportedOperationExceptionError with a vague exception message of null that gets thrown on the iter.remove() line. It seems that some Java Iterators don’t support the remove method and will throw this exception.

I can’t change the widgetService.getAllWidgets() method to return a List<Widget> and am stuck with the Widget[] array return value.

So I ask: what can I do to loop through my widgets array and dynamically prune out ones that are named “Melvin“?

Answer 1

If you can afford it, just make a mutable copy of the list. Replace

List<Widget> widgets = Arrays.asList(widgetArray);

with

List<Widget> widgets = new ArrayList<Widget>(Arrays.asList(widgetArray));