[WICKET-1148] AbstractTree utilizes Collections.EMPTY_LIST for a node's children container which causes errors when adding children

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0-beta1, 1.3.0-beta2, 1.3.0-beta3, 1.3.0-beta4, 1.3.0-rc1
• Fix Version/s: 1.3.0-rc2
• Component/s: wicket
• Assignee: Unassigned
• Reporter: Doug Leeper
• Created: 12/Nov/07 04:45
• Updated: 12/Nov/07 23:49
• Resolved: 12/Nov/07 23:49

Description

AbstractTree utilizes Collections.EMPTY_LIST for a node's children container. This assumes that this node will never have children during its lifecycle as EMPTY_LIST will always be empty since it does not support add(int, Object)

To fix, change item = Collections.EMPTY_LIST with item = new ArrayList(0);

private final void buildItemChildren(TreeItem item)
{
List items;

// if the node is expanded
if (isNodeExpanded((TreeNode)item.getModelObject()))

{ // build the items for children of the items' treenode. items = buildTreeItems(nodeChildren((TreeNode)item.getModelObject()), item.getLevel() + 1); }

else

{ // it's not expanded, just set children to an empty list //items = Collections.EMPTY_LIST; items = new ArrayList(0); }

item.setChildren(items);
}