Why is an UnsupportedOperationException thrown?

Question

Java

List<Integer> list1 = Arrays.asList(10,20,60,30,22,70,89);

        List<Integer> list2 = Arrays.asList(1,2,45,23,89,66,87,33,19,39);

        //list1.forEach(System.out::println);

        list1.addAll(list2);

Exception in thread "main" java.lang.UnsupportedOperationException // Throws addAll()

Answer 1

Array.asList()is just a wrapper over an array with an interface List. And arrays have a fixed size, so adding
and removing elements is not supported. If you want to fill with Listvalues ​​from an array , then do this:
List list = new ArrayList(Arrays.asList(1,2,3));