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From Jörg Herbst <elron...@web.de>
Subject Re: Iterator problems collections
Date Sat, 11 Dec 2004 10:56:37 GMT
Hi, as far as I could test the code, I get the results I expected 
(calling .iterator gets me
an iterator containing user objects). The problem seems to be when calling
CollectionsUtils.filter(...), I don't know the details of the 
CollectionUtils implementation
but the method seems to call some other behaviour than I expect.
My code works fine as long as I direct call my iterator() method 
everything is fine,
but using CollectionUtils something gets wrong.

Thx for any ideas
Joerg

> I can't see anything wrong with what you've sent, but I don't have the 
> complete code. I suggest you break your task down into parts and check 
> whether you really are converting the objects, or whether perhaps you 
> are converting them at the wrong time in your logic.
> Stephen
>
> To: <commons-user@jakarta.apache.org>
> Sent: Friday, December 10, 2004 6:05 PM
> Subject: Iterator problems collections
>
>
>> Hi folks,
>>
>> I've got a problem with the CollecionUtils.filter method and
>> the Iterator wrappers. I've written a custom Collections class
>> which stores a tree data structure (based on DefaultMutableTreenode).
>>
>> I want to hide the implementation (the usage of
>> DefaultMutableTreeNode) and provided an iterator() methods which
>> should return my user objects:
>>
>>    /**
>>     * Gets an iterator with all user objects
>>     */
>>    public Iterator iterator() {
>>        Iterator it = new EnumerationIterator(
>>            root.breadthFirstEnumeration(),this);
>>        Iterator tranformedIt =
>>            IteratorUtils.transformedIterator(it,
>>                new TreeNodeToUserObjectTransformer());
>>        return tranformedIt;
>>    }
>>
>>    /**
>>     * Internal Transformer class for converting a TreeNode
>>     * to it's user object
>>     */
>>    private class TreeNodeToUserObjectTransformer implements 
>> Transformer {
>>        public Object transform(Object o) {
>>            DefaultMutableTreeNode node = (DefaultMutableTreeNode) o;
>>            return node.getUserObject();
>>        }
>>       }
>>
>> Now I'm calling CollectionUtils.filter(myCollection,myPredicate)
>> and suspected to get my user objects passed to the removed(Object o)
>> method. But instead of getting the userObjects, I get
>> DefaultMutableTreeNOdes. Can anybody tell me what I'm doing wrong?
>>
>> Thx
>> Joerg
>>
>>
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>>
>
>
>
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