How to add an xml element in Java 1.4

Question

I am trying to add a "title" element but am getting a NO_MODIFICATION_ALLOWED_ERR error...

private static void saveDoc(String f) throws Exception {

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document doc = db.parse(f);

    // create DOMSource for source XML document
    DOMSource xmlSource = new DOMSource(doc);

    Node nextNode = xmlSource.getNode().getFirstChild();

    while (nextNode != null) {
        System.out.print("\n node name: " + nextNode.getNodeName() + "\n");
        if (nextNode.getNodeName().equals("map")) {
            nextNode.appendChild(doc.createElement("title")); 

the line above is throwing error:

Exception in thread "main" org.w3c.dom.DOMException: NO_MODIFICATION_ALLOWED_ERR: An attempt is made to modify an object where modifications are not allowed. at com.sun.org.apache.xerces.internal.dom.ParentNode.internalInsertBefore(Unknown Source) at com.sun.org.apache.xerces.internal.dom.ParentNode.insertBefore(Unknown Source) at com.sun.org.apache.xerces.internal.dom.NodeImpl.appendChild(Unknown Source) at myProject.Main.saveDoc(Main.java:171) at myProject.Main.main(Main.java:48)

            break;
        }

        nextNode = nextNode.getNextSibling();             
    }
}

My xml file looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<?dctm xml_app="LOPackage"?>
<!DOCTYPE map PUBLIC "-//OASIS//DTD DITA Map//EN" "file:C:/Documents%20and%20Settings/joe/Desktop//LOPackage/map.dtd">
<map xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/" class="- map/map " ditaarch:DITAArchVersion="1.1" domains="(map mapgroup-d) (topic indexing-d)">
    <topicref class="- map/topicref " href="dctm://ai/0501869e80002504?DMS_OBJECT_SPEC=RELATION_ID" type="Le"/>
    <topicref class="- map/topicref " href="dctm://ai/0501869e80002505?DMS_OBJECT_SPEC=RELATION_ID" type="Pr"/>
    <topicref class="- map/topicref " href="dctm://ai/0501869e80002506?DMS_OBJECT_SPEC=RELATION_ID" type="Pr"/>
</map>

Answer 1

Not sure if that's the reason, but check if your DOM implementation validates all the changes to the DOM. Because in you code,

nextNode.appendChild(doc.createTextNode("title"));

will attempt to create a text node as the child of map element and DITA Map doesn't allow that. Instead, try

Element title = doc.createElement("title");
title.appendChild(doc.createTextNode("title content"))
nextNode.appendChild(title);