List.addAll throwing UnsupportedOperationException when trying to add another list [duplicate]

Solution 1:

Arrays.asList returns a fixed sized list backed by an array, and you can't add elements to it.

You can create a modifiable list to make addAll work :

List<String> supportedTypes = new ArrayList<String>(Arrays.asList("6500", "7600", "8700"));

Solution 2:

This error also happens when the list is initialized with Collections.emptyList(), which is immutable:

List<String> myList = Collections.emptyList();

Instead, initialize it with a mutable list. For example

List<String> myList = new ArrayList<>();

Solution 3:

Arrays.asList returns a fixed-size list.

If you to want be able to add elements to the list, do:

List<String> supportedTypes = new ArrayList<>(Arrays.asList("6500", "7600"});
supportedTypes.addAll(Arrays.asList(supportTypes.split(",")));