Swing Components Java

import java.awt.*;
import java.net.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
public class HtmlDisplay extends JFrame implements HyperlinkListener
{
public static void main(String[] args)
{
HtmlDisplay obj=new HtmlDisplay();
obj.setSize(400,500);
obj.setVisible(true);
}
URL url;
JEditorPane html;
Document doc;
public HtmlDisplay()
{
try{
UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
url=new URL("http://202.71.136.142:8080");
html=new JEditorPane();
System.out.println("Editor created");
html.setEditable(false);
html.setPage(url);
html.addHyperlinkListener(this);
// JScrollPane scroller = new JScrollPane();
// JViewport vp = scroller.getViewport();
// vp.add(html);
// vp.setBackingStoreEnabled(true);
System.out.println("html created");
// getContentPane().add(scroller);
getContentPane().add(html);
}catch(Exception e){e.printStackTrace();}
}
public void hyperlinkUpdate(HyperlinkEvent e) {
try{
if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
{
doc = html.getDocument();
System.out.println(e.getURL());
html.setPage(e.getURL());
getToolkit().beep();
System.out.println("Listening");
}
}catch(Exception ex){
// html.setDocument(doc);
ex.printStackTrace();
}
}
}