Re: can't create BufferedImage

I am trying to create a BifferedImage and Graphics2D associated with a
JPanel. I understand that the JPanel must be displayable else the
createImage method may return null. However in my stub program below I
always get null returned from createGraphics. I obviously am missing
something but I can't figure out what. If the program below is run
without a runline parameter it does not attempt to create a
BufferedImage and it runs OK. If it is run with a runline parameter it
throws an exception because bh is null. Why?

Jay

public class Test extends javax.swing.JFrame {
    
   private static String[] opt = null;

   public Test() {
      init();
   }

   void init() {
      javax.swing.JPanel jContentPane = new javax.swing.JPanel();
      setContentPane(jContentPane);
      setSize(450, 350);
      javax.swing.JPanel graphPanel = new javax.swing.JPanel();
      java.awt.Dimension s = new java.awt.Dimension(400, 300);
      graphPanel.setPreferredSize(s);
      getContentPane().add(graphPanel, null);
      graphPanel.addNotify();
      s = graphPanel.getPreferredSize();
      System.err.println("Is JPanel=" +
         (graphPanel instanceof javax.swing.JPanel) +
         " " + s.width + "x" + s.height + " Displayable=" +
         graphPanel.isDisplayable() + " Headless= " +
         java.awt.GraphicsEnvironment.isHeadless());
      if(opt!=null && opt.length>0) {
         java.awt.image.BufferedImage bh =
            (java.awt.image.BufferedImage)graphPanel.createImage(
            s.width, s.height);
         java.awt.Graphics2D bufh = bh.createGraphics();
      }
   }

   public static final void main(String[] argv) {
      opt = argv;
      Test test = new Test();
      test.setVisible(true);
   }
}