如何将application转化成applet

如何将application转化成applet,程序如下，给分，并且希望给出转化规则。
import javax.swing.*;
import java.awt.*;
import java.net.*;
public class JSplashWindow extends JWindow implements Runnable {
Thread splashThread=null;
public JSplashWindow() {
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
JPanel splash=new JPanel(new BorderLayout());
URL url=getClass().getResource("images/Rose.jpg");
if(url!=null) {
splash.add(new JLabel(new ImageIcon(url)),BorderLayout.CENTER);}
setContentPane(splash);
Dimension screen=getToolkit().getScreenSize();
pack();
setLocation((screen.width-getSize().width)/2,(screen.height-getSize().height)/2); }
public void start() {
this.toFront();
splashThread=new Thread(this);
splashThread.start();
}
public void run() {
try {
     show();
     Thread.sleep(5000);
     }
     catch(Exception ex) {
     ex.printStackTrace();
     }
     this.dispose();
     }
static void showFrame(String title) {
JFrame frame=new JFrame(title);
frame.setSize(400,300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//----
Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
Dimension frameSize=frame.getSize();
if(frameSize.height>screenSize.height) {
frameSize.height=screenSize.height;
}
if(frameSize.width>screenSize.width) {
frameSize.width=screenSize.width;
}
frame.setLocation((screenSize.width-frameSize.width)/2,(screenSize.height-frameSize.height)/2);
frame.setVisible(true);
}
public static void main(String[] args) {
showFrame("Demo splash window");
JSplashWindow splash=new JSplashWindow();
splash.start();
}
}