下面的程序可以通过编译，但不能运行，请问方法如何调用？

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

public class FileLister extends Frame {
   TextArea text;
   public FileLister(){
      addWindowListener(new WindowAdapter(){
     public void windowClosing(WindowEvent e){ dispose();}
  });

      text=new TextArea(" ",24,80);
  text.setFont(new Font("MonoSpaced",Font.PLAIN,12));
  text.setEditable(false);
  this.add("Center",text);

  Panel p=new Panel();
  p.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
  this.add(p,"South");

  this.pack();
  
   }
   
   public void getUrl(){
      try{
     URL url=new URL("http://www.sina.com.cn/");
     String in;
     DataInputStream stream=new DataInputStream(url.openStream());
     while((in=stream.readLine())!=null){
        text.append(in);
    text.setCaretPosition(0);
     }
  }catch(MalformedURLException e){
     System.out.println("MalformedURLException:"+e);
  }catch(IOException e){
     System.out.println("IOException:"+e);
  }
   }
   
   public static void main(String [] args){
      FileLister f=new FileLister();
  f.addWindowListener(new WindowAdapter(){
     public void windowClosed(WindowEvent e){ System.exit(0);}
  });
  
  f.show();
 f.getUrl();
   }
   
}

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

public class FileLister extends Frame {
TextArea text;
public FileLister(){
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){ dispose();}
});

text=new TextArea(" ",24,80);
text.setFont(new Font("MonoSpaced",Font.PLAIN,12));
text.setEditable(false);
this.add("Center",text);

Panel p=new Panel();
p.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
this.add(p,"South");

this.pack();

}

public void getUrl(){
try{
URL url=new URL("http://www.sina.com.cn/");
String in;
DataInputStream stream=new DataInputStream(url.openStream());
while((in=stream.readLine())!=null){
text.append(in);
text.setCaretPosition(0);
}
}catch(MalformedURLException e){
System.out.println("MalformedURLException:"+e);
}catch(IOException e){
System.out.println("IOException:"+e);
}
}

public static void main(String [] args){
FileLister f=new FileLister();
f.addWindowListener(new WindowAdapter(){
public void windowClosed(WindowEvent e){ System.exit(0);}
});

f.show();
f.getUrl();
}

}


此程序没问题给分吧