| Decorates another List to create objects in the list on demand.
When the
LazyList.get(int) method is called with an index greater than
the size of the list, the list will automatically grow in size and return
a new object from the specified factory. The gaps will be filled by null.
If a get method call encounters a null, it will be replaced with a new
object from the factory. Thus this list is unsuitable for storing null
objects.
For instance:
Factory factory = new Factory() {
public Object create() {
return new Date();
}
}
List lazy = LazyList.decorate(new ArrayList(), factory);
Object obj = lazy.get(3);
After the above code is executed, obj will contain
a new Date instance. Furthermore, that Date
instance is the fourth element in the list. The first, second,
and third element are all set to null.
This class differs from
GrowthList because here growth occurs on
get, where GrowthList grows on set and add. However, they
could easily be used together by decorating twice.
This class is Serializable from Commons Collections 3.1.
See Also: GrowthList
since:
Commons Collections 3.0
version:
$Revision: 170244 $ $Date: 2005-05-15 19:30:49 +0100 (Sun, 15 May 2005) $
author:
Stephen Colebourne
author:
Arron Bates
author:
Paul Jack |
