问不同类中的JAVA JButton拒绝在按下时激活

EN

import java.awt.*;
import java.lang.*;
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.*;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
import java.util.Scanner;

public class AlphaMenu extends JFrame /*implements actionPerformed*/
{

    private GraphicsDevice gamma;
    public JButton charlie, zulu, yankee, xray;
    public JFrame beta;
    public JPanel delta, echo, foxtrot, golf, hotel;
    public JTextArea whiskey, victor;
    public BorderLayout uniform;
    public ImageIcon bg;
    public JLabel tango;
    public int sierra, romeo;
    public Integer quebec, papa;
    public ActionEvent oscar;
    public ActionEvent november;

    public AlphaMenu()
    {
        //Initialization of Objects
        charlie = new JButton("EXIT");
        zulu = new JButton("Enter Time");
        yankee = new JButton("Enter Amount of Money");
        xray = new JButton("Calculate");
        sierra = 0;
        romeo = 0;
        quebec = new Integer(0);
        papa = new Integer(0);
        whiskey = new JTextArea(2, 15);
        victor = new JTextArea(2, 15);
        bg = new ImageIcon("background.gif");
        beta = new JFrame();
        delta = new JPanel();
        echo = new JPanel();
        foxtrot = new JPanel();
        golf = new JPanel();
        hotel = new JPanel();
        uniform = new BorderLayout();
        ImageIcon bg = new ImageIcon("background.gif");
        tango = new JLabel("");

        tango.setIcon(bg);

        //Modification of panels
        beta.add(delta, uniform.PAGE_END);
        beta.add(golf, uniform.PAGE_START);
        beta.add(echo, uniform.LINE_START);
        beta.add(foxtrot, uniform.LINE_END);
        beta.add(hotel, uniform.CENTER);

        golf.add(tango);

        //Modification of JButton charlie & adding of JButtons
        charlie.setPreferredSize(new Dimension(100, 50));
        delta.add(charlie);
        charlie.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                System.exit(0);
            }
        });
        echo.add(whiskey);
        echo.add(yankee);
        foxtrot.add(victor);
        foxtrot.add(zulu);


        //Modification of JFrame beta
        beta.setUndecorated(true);
        beta.setExtendedState(JFrame.MAXIMIZED_BOTH);
        beta.setResizable(false);
        beta.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        beta.setVisible(true);
    }

    public void buttonSetup() throws NumberFormatException
    {
        //Modification of JButton yankee & JTextArea whiskey & int sierra
        romeo = quebec.parseInt(whiskey.getText());
        yankee.setPreferredSize(new Dimension(300, 50));
        yankee.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent oscar)
            {
                System.exit(0);
            }
        });

        //Modification of JButton zulu & JTextArea victor & int romeo
        sierra = papa.parseInt(victor.getText());
        zulu.setPreferredSize(new Dimension(300, 50));
        zulu.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent november)
            {
                System.exit(0);
            }
        });

    }

    public void actionPerformed(ActionEvent e)
    {
    }

    public static void main(String[] args)
    {
        new AlphaMenu();
    }
}