MathGraphicsJPanel no output

Question

I am trying to create a Java frontend for Mathematica. Following examples from J/Link guide and looking around the API manual I came up with this code:

public class Mathematica extends MathJFrame {
public Mathematica(String[] args) {
    initComponents();

     try {
        ml = MathLinkFactory.createKernelLink(args);
    } catch (MathLinkException e) {
        System.out.println("Fatal error opening link: " + e.getMessage());
    }

    try {
        ml.discardAnswer();

        ml.evaluate("2+2");
        ml.waitForAnswer();

        int result = ml.getInteger();
        System.out.println("2 + 2 = " + result);

        graphic1.setLink(ml);
        graphic1.setMathCommand("Plot[x,{x,0,1}]");
        graphic1.repaintNow();
        System.out.println(graphic1.getMathCommand());

    } catch (MathLinkException e) {
        System.out.println("Fatal error opening link: " + e.getMessage());
    } finally {
        ml.close();
    }
    private KernelLink ml = null;
}

Graphics.java:

public class Graphic extends MathGraphicsJPanel {
   public Graphic() {

   }
}

I know the link is working because I get 2 + 2 = 4 displayed in console but the panel where the graph output is expected is empty. Also, does J/Link not ship with sample programs anymore?

Thanks for any suggestions.

Answer 1

Looks like it was a bug in Mathematica. I just noticed that I was running 8.0.0 and updated to 8.0.4 and it is working now. Too bad the panel is not interactive. I assume I can rotate and interact with it only when viewing from mathematica's own notebook interface.