XML Edior

[renu richard]

Hi,
I wanna develop XML editor tool. Which does functions like parsing and giving the value if i give the node name. Can you please give me any URL or refer to some useful sites where i can get much more information on how to do this. Thanks.

[Rob Spoor]

I've created an XML viewer (no editing possible) using JDOM. That could be your first step too.

[renu richard]

Rob,
It would be great help, if you could share the code or share some ideas with me, so that i could get some ideas on how to proceed with this. Thanks

[Rob Spoor]

Have you checked out JDOM already? Check out the org.jdom.input.SAXBuilder for ways to create a Document from an existing source. You can then get your root element.

Since my setup had no requirement of changing XML nodes, I just subclassed DefaultMutableTreeNode:

public final class XMLTreeNode extends DefaultMutableTreeNode
{
    /**
     * The serial version UID.
     */
    private static final long serialVersionUID = 7351339512855397838L;
 
    /**
     * The XML element.
     */
    private Element element;
 
    /**
     * Creates a new <code>XMLTreeNode</code>, and recursively adds the children
     * of the specified element as child nodes.
     *
     * @param element The element of the XMLTreeNode.
     */
    public XMLTreeNode(Element element)
    {
        super(element);
        this.element = element;
        for (Iterator i = element.getChildren().iterator(); i.hasNext(); )
        {
            add(new XMLTreeNode((Element)i.next()));
        }
    }
 
    /**
     * @return The element of this node.
     */
    public Element getElement()
    {
        return element;
    }
 
    /**
     * @return A string representation of this <code>TreeNode</code>.
     */
    public String toString()
    {
        return element.getName();
    }
}

(GPL'ed )
As you see, the constructor creates the entire sub tree, so you only need to call the constructor yourself for the root node.

However, since you will be editing, you may choose to go for a custom TreeModel instead. The following is an example of how you could do it:

public class JDOMTreeModel implements TreeModel
{
    private Element root;
 
    public Object getChild(Object parent, int index)
    {
        Element element = (Element)parent;
        return element.getContent(index);
    }
 
    public int getChildCount(Object parent)
    {
        Element element = (Element)parent;
        return element.getContentSize();
    }
 
    public boolean isLeaf(Object node)
    {
        Element element = (Element)node;
        return element.getContentSize() == 0;
    }
 
    ...
}

If you modify your DOM tree, don't forget to fire events for the TreeModelListeners though. Just look at the source of DefaultTreeModel (available in src.zip) at how to fire events. fireTreeNodesInserted is one of the event firing methods.