删除XML结构Java DOM中的节点

Question

I'm trying to delete a Node from a XML File parsed with DOM in Java.

private Node deleteChildNode (Node node, String nodeName )
{
    Node tempNode = null;
    NodeList nl = node.getChildNodes();
    for (int i = 0; i < nl.getLength(); i++)
    {
        tempNode = nl.item(i);
        if (tempNode.getNodeName().equals(nodeName))
        {                   
            tempNode= node.removeChild(tempNode);                   
        }        
    }
    return node;
}

Calling with:

nodeClone = deleteChildNode(nodeClone, "L123");

But the Node has not been deleted.

NodeList nl = nodeClone.getChildNodes();
        for (int i = 0; i < nl.getLength(); i++)
            System.out.println(nl.item(i).getNodeName());

Shows the "L123" Node.

Thanks in advance!

Answer 1

If you have more than one node with the node name under the given node, then your code will not work because you will skip nodes. using a NodeList while removing nodes is a bit tricky. basically, when you remove the child node, if modifies the NodeList so that all the following nodes get shifted back one index. (similar to removing elements from a List while iterating over the list using indexes). a simple fix would be to add "--i;" after you remove a child node.

Answer 2

I use this little handy method to clear children of the passed node:

public static void clearChildNodes(Node node){
    while(node.hasChildNodes()){
        NodeList nList = node.getChildNodes();
        int index = node.getChildNodes().getLength() - 1;

        Node n = nList.item(index);
        clearChildNodes(n);
        node.removeChild(n);
    }

}