Inserting an element into an XML document

Question

I am simply looking insert a new element into an existing XML Document using JDOM. Here is my code so far:
public class UserDocumentWriter {
     private SAXBuilder builder;
     private Document document;
     private File file = new File("/path/to/file/users.xml");
     private Element rootElement;
     public UserDocumentWriter() {
          builder = new SAXBuilder();
          try {
               document = builder.build(file);
               rootElement = document.getRootElement();
          } catch (IOException ioe) {
               System.err.println("ERROR: Could not build the XML file.");
          } catch (JDOMException jde) {
               System.err.println("ERROR: " + file.toString() + " is not well-formed.");
     public void addContact(String address, String contact) {
          List contactList = null;
          Element contactListElement;
          Element newContactElement = new Element("contact");
          newContactElement.setText(contact);
          List rootsChildren = rootElement.getChildren();
          Iterator iterator = rootsChildren.iterator();
          while (iterator.hasNext()) {
               Element e = (Element) iterator.next();
               if (e.getAttributeValue("address").equals(address)) {
                    contactListElement = e.getChild("contactlist");
                    contactListElement.addContent(newContactElement);
                    writeDocument(document);
     public void writeDocument(Document doc) {
          try {
               XMLOutputter output = new XMLOutputter();
               OutputStream out = new FileOutputStream(file);
               output.output(doc, out);
          } catch (FileNotFoundException ntfe) {
               System.err.println("ERROR: Output file not found.");
          } catch (IOException ioe) {
               System.err.println("Could not output document changes.");
     }However, the problem is, the newly added element will always be appended to the end of the last line, resulting in the following:
<contactlist>
            <contact>[email protected]</contact><contact>[email protected]</contact></contactlist>Is there anyway in which I can have the newly added element create it's own line for the purpose of tidy XML? Alternatively is there a better methodology to do the above entirely?

Answer 1

Your question is not very clear.
Do you want to know How to insert an element into an XML document?
Answer: I can see you already know how to do it. You have added the element using addContent()
or do you want to know How to display the XML in a tidy format?
Answer: to view the XML in a properly formatted style you can you the Format class. A very basic way of viewing the XML would be:
   * Prints the Document to the specified file.
   * @param doc
   * @param filename
   * @param formatting
  public static void printDocToFile(Document doc, String strFileName,
      boolean formatting)
    XMLOutputter xmlOut = null;
    if (!formatting)
      xmlOut = new XMLOutputter();
    } else
      Format prettyFormat = Format.getPrettyFormat();
      prettyFormat.setOmitEncoding(false);
      prettyFormat.setOmitDeclaration(false);
      xmlOut = new XMLOutputter(prettyFormat);
    try
      if (doc != null)
        FileWriter writer = new java.io.FileWriter(strFileName, true);
        xmlOut.output(doc, writer);
        writer.flush();
        writer.close();
      } else
        System.out.println("Document is null.");
    catch (Exception ex)
      System.out.println(ex);
  }