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[jdom-interest] Proper way to prune a tree with removeContent

Jeff Rosler

2005-11-09

Replies:

Hi All,

 

I’m running JDOM 1.0 and I just ran into an interesting corruption problem. In my code, I’m parsing XML elements in a doc and removing specific elements (branches) based on their attribute values. Please see the code snippet below.

 

I initially call this code with profileDOM(null,doc.getRootElement()). It recursively parses the tree until my checkAttributes() method returns false. At this point, it removes that element. If it doesn’t return false then it gets the list of children and calls itself (recursion) for each child.

 

The problem occurs in the removeContent call. The removeContent correctly removes the content, but appears to screw up the list. The second time that removeContent is called with a different parent, it removes the wrong content node. It appears that the internal list somehow gets screwed up. While I was debugging this in my IDE, I took a look at the content list in the parent element and the parent.indexOf(node) was returning the wrong index for the actual content. In my sample, it returned a text node instead of an element!

 

So, two questions –

If this isn’t the correct type of code to prune content, what is? I remember trying an iterator a while back, but ended up getting some exception.

The second is, isn’t this a bug? Is this the right forum to report it?

 

    public void profileDOM(Element parent, Element node)  throws Exception

    {

        if (parent != null && !checkAttributes(node))

        {

            // previously just doing parent.removeContent(node);

            int index = parent.indexOf(node);

            Content content = parent.removeContent(index);

            if (content == null)

            {

                logger.info("Removal of element <" + node.getName() + "> failed!");

            }

        }

        else

        {

                List list = node.getChildren();

                for(int i=0;i<list.size();i++)

                {

                    Element child = (Element)list.get(i);

 

                    // check to see if we should delete child

                    profileDOM(node,child);

                }

        }

    }

 

Thanks,

Jeff Rosler
Consultant
Flatirons Solutions Corporation
XML and Content Management Solutions
2555 55th Street
Suite 100D
Boulder, CO  80301
303-544-0514 x111
jeff.rosler@flatironssolutions.com

"The man with a new idea is a crank until the idea succeeds"

Mark Twain

 

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