用单例模式修改下列代码public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); SwingUtilities.invokeLater(new Runnable() { public void run() { splashFrame = new SplashFrame(); splashFrame.setVisible(true); init(); } }); }

可以将SplashFrame设计为单例类，使得在整个应用程序中只有一个SplashFrame对象。修改后的代码如下：

public class MyApp {
    private static MyApp instance = null;
    private SplashFrame splashFrame;

    private MyApp() throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        splashFrame = new SplashFrame();
        splashFrame.setVisible(true);
        init();
    }

    public static MyApp getInstance() throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
        if (instance == null) {
            instance = new MyApp();
        }
        return instance;
    }

    private void init() {
        // 进行应用程序初始化操作
    }

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
        MyApp app = MyApp.getInstance();
    }
}

在这个代码中，MyApp类被设计成了单例模式，通过getInstance()方法获取唯一的MyApp实例。在构造函数中进行了一些初始化工作，包括设置系统外观和创建SplashFrame对象并显示出来，而init()方法则用来进行应用程序的初始化操作。在main()方法中，通过getInstance()方法获取MyApp的实例，这样整个应用程序中只有一个MyApp实例，也只有一个SplashFrame对象。