Thread: Button question

I have a button, start, that starts a countdown timer. While the timer is counting down the button stays pressed. I need to be able to press another button, stop, while the timer is counting down.

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;

public class MicrowaveWindow extends JFrame implements KeyListener{

// Declaring variables
private JPanel east = null;
private JPanel south = null;
private static JPanel north = null;
private JLabel screen = null;
public static JPanel center = new JPanel();
public static String secString = null;
public static String minString = null;
public static int stopping;

// Constructing the window
public MicrowaveWindow() {
setTitle("Microwave Interface");
setSize(600,400);
setVisible(true);

east = new JPanel();
add(east, BorderLayout.EAST);
screen = new JLabel("");
east.add(screen);
east.setLayout(new GridLayout(4,3));

south = new JPanel();
add(south, BorderLayout.SOUTH);
south.add(screen);

north = new JPanel();
add(north, BorderLayout.NORTH);
north.add(screen);

center.setLayout(new GridLayout(4, 3));
add(center);
center.setBackground(Color.LIGHT_GRAY);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
this.addKeyListener(this);


// Constructing buttons
JButton[] nButtons = new JButton[10];
for(int i = 0; i < nButtons.length; i++) {
nButtons[i] = new JButton("" + i);
nButtons[i].addActionListener(new NumAction());
nButtons[i].addKeyListener(this);
}
for(int i = 0; i < 9; i++) {
east.add(nButtons[i + 1]);

}

JButton stop = new JButton("Stop");
east.add(stop);

east.add(nButtons[0]);

final JButton start = new JButton("Start");
east.add(start);

JButton open = new JButton("Open");
south.add(open);


// Key press events

start.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
System.out.println("Start");
center.setBackground(Color.YELLOW);
start.setEnabled(true);
Timer(minutes, seconds);

}
});


stop.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
System.out.println("Stop");
center.setBackground(Color.LIGHT_GRAY);
timeLabel.setText(sdf.format(0000));
q="0";w="0";e="0";r="0";
}
});

open.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
System.out.println("Open");
center.setBackground(Color.LIGHT_GRAY);
}
});
}

//unnecessary code
public void keyPressed(KeyEvent ke) {}
public void keyReleased(KeyEvent ke) {}

public void keyTyped(KeyEvent ke) {
addNum("" + ke.getKeyChar());
}


// NumAction class

private class NumAction implements ActionListener {
public void actionPerformed(ActionEvent event) {
String text = event.getActionCommand();
addNum(text);
}
}

// Reading in the numbers
public static String q="0";
public static String w="0";
public static String e="0";
public static String r="0";
public static int seconds=0;
public static int minutes=0;
public static JLabel timeLabel = new JLabel();
static SimpleDateFormat sdf = new SimpleDateFormat("mm:ss");

public void addNum(String text) {


String clockset = screen.getText();
clockset += text;
r=e;
e=w;
w=q;
q=clockset;

timeLabel.setText(r+e+":"+w+q);



int rInt = Integer.parseInt(r);
int eInt = Integer.parseInt(e);
int wInt = Integer.parseInt(w);
int qInt = Integer.parseInt(q);
seconds = wInt*10 + qInt;
minutes = rInt*10 + eInt;

}

// Running the timer method

// Main methods
public static void main(String[] args) {
JFrame f = new MicrowaveWindow();
f.setVisible(true);
north.add(timeLabel);
timeLabel.setText(sdf.format(0000));

}


public static void Timer(int counter2, int counter){
for(int i = 0; counter>0; i++){

counter--;

secString = Integer.toString(counter);
minString = Integer.toString(counter2);

if(counter<=9){
secString = "0" + secString;
}
if(counter2<=9){
minString = "0" + minString;
}
System.out.print(minString);
System.out.println(secString);


// countdown display


timeLabel.setText(minString + ":" + secString);


if(counter<=0){
counter = 60;
counter2--;
if(minString.equals("00") && secString.equals("00")){
break;
}
}

try {
Thread.sleep(1000);
} catch (InterruptedException e) {

e.printStackTrace();
}
}
timeLabel.setText(sdf.format(0000));
q="0";w="0";e="0";r="0";
center.setBackground(Color.LIGHT_GRAY);
}











public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub

}
}