Java - placeholder on textfield

I use to override the text fields paint method, until I ended up with more custom text fields then I really wanted...

Then I found this prompt API which is simple to use and doesn't require you to extend any components. It also has a nice "buddy" API

This has now been included in the SwingLabs, SwingX library which makes it even eaiser to use...

I found this on the oracle forums.

public class TextFieldWithPrompt extends JTextField{

@Override
protected void paintComponent(java.awt.Graphics g) {
    super.paintComponent(g);

    if(getText().isEmpty() && ! (FocusManager.getCurrentKeyboardFocusManager().getFocusOwner() == this)){
        Graphics2D g2 = (Graphics2D)g.create();
        g2.setBackground(Color.gray);
        g2.setFont(getFont().deriveFont(Font.ITALIC));
        g2.drawString("zip", 5, 10); //figure out x, y from font's FontMetrics and size of component.
        g2.dispose();
    }
  }

https://forums.oracle.com/forums/thread.jspa?threadID=1349874