«

I'm finding the same object twice in my HashSet, and since I'm building
that HashSet using

Set getSelectedContentItems()
{
Set ciSet = new HashSet();
Iterator chIt = children.iterator();
while (chIt.hasNext())
{
TreeNode child = (TreeNode)chIt.next();
ciSet.addAll(child.getSelectedContentItems());
}
ciSet.add(myContentItem);
return ciSet;
}

I'm wondering if somehow addAll is adding things without enforcing the
Set's constraint against duplicate items. I've already checked that the
class "MyContentItem" class has a "public boolean equals(Object other)"
method.

--
Paul Tomblin <> http://blog.xcski.com/
Networks are like sewers ... My job is to make sure your data goes
away when you flush, and to stop the rats climbing into your toilet
through the pipes. -- Network administration, as told by Tanuki

On Fri, 08 Dec 2006 19:24:15 -0000, Paul Tomblin
<ptomblin+> wrote:

> I'm finding the same object twice in my HashSet, and since I'm building
> that HashSet using
>
> Set getSelectedContentItems()
> {
> Set ciSet = new HashSet();
> Iterator chIt = children.iterator();
> while (chIt.hasNext())
> {
> TreeNode child = (TreeNode)chIt.next();
> ciSet.addAll(child.getSelectedContentItems());
> }
> ciSet.add(myContentItem);
> return ciSet;
> }
>
> I'm wondering if somehow addAll is adding things without enforcing the
> Set's constraint against duplicate items. I've already checked that the
> class "MyContentItem" class has a "public boolean equals(Object other)"
> method.

Does it also over-ride hashCode(), and are the two methods consistent with
each other?

Dan.

--
Daniel Dyer
http://www.uncommons.org

Paul Tomblin wrote:
> I'm finding the same object twice in my HashSet, and since I'm building
^^^^
> that HashSet using


> Set's constraint against duplicate items. I've already checked that the
> class "MyContentItem" class has a "public boolean equals(Object other)"
> method.

And an @Override public int hashCode()?

Tom Hawtin

In a previous article, ptomblin+ (Paul Tomblin) said:
>Set's constraint against duplicate items. I've already checked that the
>class "MyContentItem" class has a "public boolean equals(Object other)"
>method.

Thomas and Daniel hit the nail on the head - I forgot to override
hashCode. Thanks.


--
Paul Tomblin <> http://blog.xcski.com/
C has features?? I thought the whole point of that language was to
offer nothing but bare metal.
-- David P. Murphy