class ButtonAction implements ActionListener
{
    MyLinkedList list1 = new MyLinkedList();
    public void actionPerformed(ActionEvent e)
    {
        if(e.getSource() == button1)
        {
            String s1 = text1.getText();
            String s2 = "02";
            List.add(List.size(),s1);
            List.add(list1.size(),s2);
            /*对不起，你这地方是要用String
             * 详情可以参照
             * http://www.eclipselight.org/swt-jface/1022/
             * */
            int n = list1.getSection(s1);// 这个地方 ，s1改s2 就会出错
            text3.setText((String)list1.getElement(n));
        }
        else if(e.getSource() == button2)
        {
            //这个不是很清楚
            String s2 = text2.getText();//这个地方 还是会报错 为什么在上面就能行呢？？
            int n = list1.getSection(s2);
            text3.setText((String)list1.getElement(n));
        }
    }
}