怎改以下代码请“高手”指教？？？？？？？？？？？？？？

ufopsdc

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class test extends JFrame implements ActionListener{
JButton tk1 = new JButton("n1";
Vector v = new Vector();
JScrollPane sp = new JScrollPane();
JList list1 = new JList();
FlowLayout fl = new FlowLayout();
JPanel jp = new JPanel();
public test(){
super("wieor";
setSize(300,190);
setDefaultCloseOperation(EXIT_ON_CLOSE);

jp.setLayout(fl);
String s[] ={"n01","no2","no3"};
sp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
list1.setListData(s);

getViewport().setView(list1);//这里应怎加实例名？？？？？？？？
jp.add(tk1);
jp.add(sp);
tk1.addActionListener(this);
this.setContentPane(jp);
show();
}
public void actionPerformed(ActionEvent e){

if(e.getSource()==tk1){
String tr[] = list1.getItems();//JList没有这个方法，那么可用这个类的什么方法取得所有表中的项？？？？？？？？？？？？
v.add(tr);
v.remove(0);
list1.setListData(v);
}
}
public static void main(String arg[]){
test ts = new test();
}
}