java泛型add_java泛型和addAll方法 (java generics and the addAll method)

2010-04-23 19:59:45

1

What is the correct type of argument to the addAll(..) method in Java collections? If I do something like this:

List extends Map> currentList = new ArrayList>();

Collection> addAll = new ArrayList>();

// add some hashmaps to the list..

currentList.addAll(addAll);

I understand I need to initialize both variables. However, I get a compilation error (from eclipse):

Multiple markers at this line

- The method addAll(Collection extends capture#1-of ? extends Map>) in the type List> is not applicable for the arguments (List

Map>)

- The method addAll(Collection extends capture#1-of ? extends Map>) in the type List> is not applicable for the arguments

(Collection>)

what am I doing wrong?