Error in creating xml file from java object

[Juliettef]

when i try to store my CreateNode object in a xml file it gives me the following error\[code\]java.lang.InstantiationException: GraphPanel$CreateNodeContinuing ...java.lang.Exception: XMLEncoder: discarding statement XMLEncoder.writeObject(GraphPanel$CreateNode);Continuing ...\[/code\]here is my node class \[code\]public static class CreateNode { private Point p; private int r; private String NAME; private String nodeid; private boolean selected = false; private boolean fnode; private Rectangle b = new Rectangle(); /** * Construct a new node. */ public CreateNode(String nodeid, Point p, int r, String NAME, boolean fnode) { this.nodeid = nodeid; this.p = p; this.r = r; this.NAME = NAME; setBoundary(b); System.out.print(p.toString()); } /** * Calculate this node's rectangular boundary. */ private void setBoundary(Rectangle b) { b.setBounds(p.x - r, p.y - r, 2 * r, 2 * r); } /** * Select each node in r. */ public static void selectRect(List<CreateNode> list, Rectangle r) { for (CreateNode n: list) { n.setSelected(r.contains(n.p)); } } /** * Toggle selected state of each node containing p. */ public static void selectToggle(List<CreateNode> list, Point p) { for (CreateNode n: list) { if (n.contains(p)) { n.setSelected(!n.isSelected()); } } }}\[/code\]and an object is created in the following class\[code\]private class NewNodeAction extends AbstractAction { String Name; boolean firstnode = false; public NewNodeAction(String name) { super(name); this.Name = name; } public void actionPerformed(ActionEvent e) { CreateNode.selectNone(nodes); Point p = mousePt.getLocation(); String Nodeid = ID.giveid(); CreateNode n = new CreateNode(Nodeid, p, radius, Name, firstnode); n.setSelected(true); nodes.add(n); repaint(); }}\[/code\]And i try to serialize/store the object in xml file here but it gives me error\[code\]private class Serialize extends AbstractAction { public Serialize(String name) { super(name); } public void actionPerformed(ActionEvent e) { ListIterator<CreateNode> Fiter = nodes.listIterator(); while (Fiter.hasNext()) { CreateNode n = Fiter.next(); FileOutputStream os; try { os = new FileOutputStream("D:/DM1/pert.xml"); XMLEncoder encoder = new XMLEncoder(os); encoder.writeObject(n); encoder.close(); } catch (FileNotFoundException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } } }}\[/code\]