使用defaultlistmodel作为参数的通用方法语法

Question

DefaultListModel<String> strings = new DefaultListModel<String>();
DefaultListModel<Integer> integers = new DefaultListModel<Integer>();

private <T> void sortList(DefaultListModel<T> defaultListModel)
{
    T objects[] = (T[])defaultListModel.toArray(); 

    defaultListModel.clear();

    Arrays.sort(objects);

    for (T object: objects)
    {
        defaultListModel.addElement(object);
    }
}

how can i write the above without getting an unchecked cast warning and without using @suppress?

Answer 1

You are not doing anything worng. The reason for unchecked cast warning is because the DefaultListModel toArray() method is not generic . it returns an Object array which when you type cast to your generic class array T[] , compiler gives the warning. You can avoid the warnings by putting the below line above your method sortList:-

@SuppressWarnings("unchecked")
private <T> void sortList(DefaultListModel<T> defaultListModel)
{
      .....
}