Replacing a JLabel

Question

Hello
I�ve got a problem with replacing a JLabel.
I know it�s unusual to replace a JLabel, but I�ve got a class interpreting internal Error-Codes into �userfriendly messages�.
And not only the Text is changing but also the background- and foreground-color. Sometimes even the font style.
Short: it is like a Renderer for a single JLabel.
My Class GuiController (that keeps the instance of my GUI) sets the new JLabel at the predefined place in my GUI.
I don�t see it change but when I ask the Text of the Label (myLabel.getText( );) I get the new Text.
There must be something simple I have not found yet. Or is it such a big no-no that I should solve it in a totally different way?
Maybe it would be better to actually write a JLabel-Renderer (?)
(But I would need 5 of them, because there are 5 Labels with different intepretations and Layouts...)
here is a short demonstration program:
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class ReplaceJLabelTest {
  public ReplaceJLabelTest(){
    final TestGui l_oGui = new TestGui();
    try {
      Thread.sleep(1000);
    } catch (Exception e) {
      e.printStackTrace();
    SwingUtilities.invokeLater( new Runnable() {
      public void run() {
        l_oGui.setLabel(new JLabel("it is the new label"));
        l_oGui.getContentPane().validate();
        l_oGui.repaint();
        System.out.println(l_oGui.getLabel().getText()); // <-- returns "it is the new label" but I still see the old text.
  public static void main(String[] args) {
    new ReplaceJLabelTest();
  private class TestGui extends JFrame {
    JFrame m_oFrame = new JFrame();
    JLabel m_oLabel = new JLabel("this is the old label");
    public TestGui() {
      m_oFrame.getContentPane().add(m_oLabel);
      m_oFrame.pack();
      m_oFrame.setVisible(true);
    public void setLabel(JLabel p_strLabel) {
      m_oLabel = p_strLabel;
    public JLabel getLabel() {
      return m_oLabel;
}I tried solutions given in older topics.
Like http://forum.java.sun.com/thread.jspa?forumID=257&threadID=415307
or
l_oGui.pack();
l_oGui.invalidate();
l_oGui.repaint();
l_oGui.getLabel().repaint();It did not really work for me...
Thanks for taking the time to read this :)
Greetings
Sophia

Answer 1

You can use the setUI function for installing a new UI.
You can create a custom UI class by extending BasicLabelUI:
http://java.sun.com/j2se/1.5.0/docs/api/javax/swing/plaf/basic/BasicLabelUI.html
Override protected void installDefaults(JLabel c) and set the foreground, background and font for c.