Unable to modify XML file in by using servlet

Question

I am trying to modify a xml file located in my apache tomcat directory.

I am using this code to modify:

String filePath = getServletContext().getRealPath("")
            + File.separator +"\\xml_server.xml";
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    try {

        DocumentBuilder builder = factory.newDocumentBuilder();
        Document doc = builder.parse(new File(filePath));

        nList = doc.getElementsByTagName("item");

        Node menu = doc.getFirstChild();

            Element item = doc.createElement("item");
            menu.appendChild(item);

            Element id = doc.createElement("id");
            id.appendChild(doc.createTextNode(String.valueOf(nList.getLength()+2)));
            item.appendChild(id);

            Element name = doc.createElement("name");
            name.appendChild(doc.createTextNode(fileName));
            item.appendChild(name);

            Element version = doc.createElement("version");
            version.appendChild(doc.createTextNode("1"));
            item.appendChild(version);

            TransformerFactory transformerFactory = TransformerFactory
                    .newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(new File(filePath));
            transformer.transform(source, result);



    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();

}

Here is the error which I'm face while running this:

type Exception report

message Servlet execution threw an exception

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Servlet execution threw an exception
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClass(Unknown Source)
java.security.SecureClassLoader.defineClass(Unknown Source)
java.net.URLClassLoader.defineClass(Unknown Source)
java.net.URLClassLoader.access$100(Unknown Source)
java.net.URLClassLoader$1.run(Unknown Source)
java.net.URLClassLoader$1.run(Unknown Source)
java.security.AccessController.doPrivileged(Native Method)
java.net.URLClassLoader.findClass(Unknown Source)
java.lang.ClassLoader.loadClass(Unknown Source)
java.lang.ClassLoader.loadClass(Unknown Source)
org.apache.xerces.parsers.AbstractDOMParser.startDocument(Unknown Source)
org.apache.xerces.impl.dtd.XMLDTDValidator.startDocument(Unknown Source)
org.apache.xerces.impl.XMLDocumentScannerImpl.startEntity(Unknown Source)
org.apache.xerces.impl.XMLVersionDetector.startDocumentParsing(Unknown Source)
org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
fr.studec.FileUploadServlet.updateXml(FileUploadServlet.java:131)
fr.studec.FileUploadServlet.doPost(FileUploadServlet.java:106)
javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

score 1 · Accepted Answer · edited May 23 '17 at 12:23

From exception it is clear that the class org/w3c/dom/ElementTraversal cannot be found.java.lang.NoClassDefFoundError occurs when a class is not available or cannot be found at runtime. This class is part of Xalan and Xerces APIs There are many possible reasons for thisnto occur.

Below links to previously asked questions can make it clear

AppEngine Error [ java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal ]

NoClassDefFoundError: org/w3c/dom/ElementTraversal

Unable to modify XML file in by using servlet

1 Answers1