关于计算器事件的监听问题求指教！

package swing;

import javax.swing.*;

import java.awt.event.*;

import java.awt.*;

public class MenuTest implements ActionListener{

public MenuTest(){

JMenuBar menubar= new JMenuBar();

JMenu menu=new JMenu("查看(V)");

JMenuItem jmenuitem = new JMenuItem("科学型(T)");

JMenuItem jmenu = new JMenuItem("标准型(S)");

JMenuItem jmenu1 = new JMenuItem("分组型(w)");

menubar.add(menu);

menu.add(jmenu);

menu.add(jmenuitem);

menu.add(jmenu1);

menu=new JMenu("编辑(E)");

JMenuItem j1 = new JMenuItem("复制(c) Ctrl+c");

JMenuItem j2 = new JMenuItem("粘贴(p) Ctrl+v");

menu.add(j1);

menu.add(j2);

menubar.add(menu);

menu=new JMenu("帮助(H)");

menubar.add(menu);

TextField text = new TextField();

JPanel panel1 = new JPanel(new GridLayout(1,1,2,2));

panel1.add(text);

Button l1 = new Button("MC");

l1.addActionListener(this);

Button l2 = new Button("MR");

l2.addActionListener(this);

Button l3 = new Button("MS");

l3.addActionListener(this);

Button l4 = new Button("M+");

l4.addActionListener(this);

Button l5 = new Button("M-") ;

l5.addActionListener(this);

Button l6 = new Button(" 1 ");

l6.addActionListener(this);

Button l7 = new Button(" 2 ");

l7.addActionListener(this);

Button l8 = new Button(" 3 ");

l8.addActionListener(this);

Button l9 = new Button(" 4 ");

l9.addActionListener(this);

Button l_ = new Button(" + ");

l_.addActionListener(this);

Button l_0 = new Button(" 5 ");

l_0.addActionListener(this);

Button l_1 = new Button(" 6 ");

l_1.addActionListener(this);

Button l_2 = new Button(" 7 ");

l_2.addActionListener(this);

Button l_3 = new Button(" 8 ");

l_3.addActionListener(this);

Button l_4 = new Button(" - ");

l_4.addActionListener(this);

Button l_5 = new Button(" 9 ");

l_5.addActionListener(this);

Button l_6 = new Button(" . ");

l_6.addActionListener(this);

Button l_7 = new Button(" 0 ");

l_7.addActionListener(this);

Button l_a = new Button(" = ");

l_a.addActionListener(this);

Button l_8 = new Button(" * ");

l_8.addActionListener(this);

Button l_9 = new Button(" / ");

l_9.addActionListener(this);

Button l_z = new Button(" -/+");

l_z.addActionListener(this);

Button l_x = new Button(" CE ");

l_x.addActionListener(this);

Button l_c = new Button(" % ");

l_c.addActionListener(this);

Button l_d = new Button("Ba");

l_d.addActionListener(this);

JPanel panel = new JPanel(new GridLayout(5,7,2,2));

panel.add(l1);

panel.add(l2); panel.add(l3);

panel.add(l4); panel.add(l5);

panel.add(l6); panel.add(l7);

panel.add(l8); panel.add(l9);

panel.add(l_); panel.add(l_0);

panel.add(l_1); panel.add(l_2);

panel.add(l_3); panel.add(l_4);

panel.add(l_5); panel.add(l_6);

panel.add(l_7); panel.add(l_a);

panel.add(l_8); panel.add(l_9);

panel.add(l_c); panel.add(l_z);

panel.add(l_d);panel.add(l_x);

JFrame jf=new JFrame("计算器");

jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

jf.add(panel1,BorderLayout.NORTH);

jf.add(panel, BorderLayout.CENTER);

jf.setJMenuBar(menubar);

jf.setSize(200, 250);

jf.setVisible(true);

}

public static void main(String[] args) {

// TODO Auto-generated method stub

new MenuTest();

}

@Override

public void actionPerformed(ActionEvent e) {

// TODO 自动生成的方法存根

}

}

//对于“查看”，“编辑”，“帮助”就不需要监听！！谢谢！！