java.lang.ClassCastException：ssg.com.client.Launcher无法强制转换为java.applet.Applet

Question

我创建了一个小applet

java.lang.ClassCastException: ssg.com.client.Launcher cannot be cast to java.applet.Applet
    at sun.applet.AppletPanel.createApplet(Unknown Source)
    at sun.applet.AppletPanel.runLoader(Unknown Source)
    at sun.applet.AppletPanel.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

这是我的代码：

package ssg.com.client.applet;

import java.applet.Applet;

public class GameApplet extends Applet
{

    private static final long serialVersionUID = -3949872561494573440L;

    public GameApplet()
    {

    }
}

applet启动并显示，但我不喜欢我的代码中有错误。我该怎么办？