帮助!当我尝试启动我的 .class 文件时,我看到应用程序弹出,然后退出。我看不到我珍贵的作品!!!有人可以看看下面的代码并告诉我我做错了什么吗?
import com.sun.j3d.utils.universe.SimpleUniverse;
import com.sun.j3d.utils.geometry.ColorCube;
import javax.media.j3d.BranchGroup;
public class Hello3d {
public Hello3d()
{
    SimpleUniverse universe = new SimpleUniverse();
    BranchGroup group = new BranchGroup();
    group.addChild(new ColorCube(0.3));
    universe.getViewingPlatform().setNominalViewingTransform();
    universe.addBranchGraph(group);
}
public static void main(String[] args) {
    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            new Hello3d();
        }
    });
}
} // end of class Hello3d