UnsupportedOperationException with List.add(Object obj)

Question

List statusCodes = Arrays.asList(OcsCustomDicInfo.acctRefundStatusCodes);
          List statusNames = Arrays.asList(OcsCustomDicInfo.acctRefundStatusNames);
          // Add an additional item          statusCodes.add(Integer.toString(statusCodes.size()));           statusNames.add("All");
          String[] statusCodesArray = (String[]) statusCodes.toArray();
          String[] statusNamesArray = (String[]) statusNames.toArray();I used the Arrays.asList to convert an Array(which is String[]) to a List,then add one item to the List with add(Object obj).
But when the debuger run to the "statusCodes.add(Integer.toString(statusCodes.size())); " breakpoint, it throws UnsupportedOperationException.
I checked the API, the relative statement is:
UnsupportedOperationException - if the add method is not supported by this list.
Why? Doesn't the Arrays.asList() return a "List" Interface,and "List" support "add()" operation,but why not support in this case?

Answer 1

Sorry,i have made a mistake when posting the code.
This is the code:
List statusCodes = Arrays.asList(OcsCustomDicInfo.acctRefundStatusCodes);
List statusNames = Arrays.asList(OcsCustomDicInfo.acctRefundStatusNames);
// Add an additional item          
statusCodes.add(Integer.toString(statusCodes.size()));
statusNames.add("All");
String[] statusCodesArray = (String[]) statusCodes.toArray();
String[] statusNamesArray = (String[]) statusNames.toArray();