I am trying to write a SlotMachine applet in Java. The code works through the first time, but when I try to hit the start button a second time, the program crashes. I know that it is an issue with the thread breaks and the Thread.start();. I tried to implement a boolean value "isRunning" instead of the breaks, but that did not work. How do I stop a thread and then start it over? Some insight would be very helpful. Thank you!
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
@SuppressWarnings("serial")
public class SlotMachine extends Frame {
private TextField textWindow1, textWindow2, textWindow3, resultWindow;
private int count1 = 0, count2 = 0, count3 = 0, result1, result2, result3;
private Button toggleButton;
public static final int HEIGHT = 150;
public static final int WIDTH = 100;
box1Thread counter1Thread = new box1Thread();
box2Thread counter2Thread = new box2Thread();
box3Thread counter3Thread = new box3Thread();
public static void main(String[] args) {
SlotMachine counterWindow = new SlotMachine();
counterWindow.setVisible(true);
}// main
public SlotMachine() {
setSize(WIDTH, HEIGHT);
addWindowListener(new WindowDestroyer());
setTitle("Slot Machine");
setBackground(Color.orange);
setLayout(new FlowLayout());
textWindow1 = new TextField(1);
add(textWindow1);
textWindow1.setText("*");
textWindow2 = new TextField(1);
add(textWindow2);
textWindow2.setText("*");
textWindow3 = new TextField(1);
add(textWindow3);
textWindow3.setText("*");
toggleButton = new Button("Start");
toggleButton.addActionListener(new ToggleButtonListener());
add(toggleButton);
resultWindow = new TextField(10);
add(resultWindow);
resultWindow.setText("");
}
private class box1Thread extends Thread {
Random generator1 = new Random();
public void run() {
while (true) {
try {
Thread.sleep(50);
result1 = ((count1++) % 4);
textWindow1.setText(Integer.toString(result1));
} catch (InterruptedException e) {
// System.err.println("Interrupted.");
int randomInt1 = generator1.nextInt(75);
for (int i = 0; i < randomInt1; i++) {
try {
Thread.sleep(50);
} catch (InterruptedException e1) {
System.err.println("Interrupted.");
}
result1 = (count1++) % 4;
textWindow1.setText(Integer.toString(result1));
}
break;
}
}
}
}
private class box2Thread extends Thread {
Random generator2 = new Random();
public void run() {
while (true) {
try {
Thread.sleep(50);
result2 = ((count2++) % 4);
textWindow2.setText(Integer.toString(result2));
} catch (InterruptedException e) {
// System.err.println("Interrupted.");
int randomInt2 = generator2.nextInt(75);
for (int i = 0; i < randomInt2; i++) {
try {
Thread.sleep(50);
} catch (InterruptedException e1) {
System.err.println("Interrupted.");
}
result2 = (count2++) % 4;
textWindow2.setText(Integer.toString(result2));
}
break;
}
}
}
}
private class box3Thread extends Thread {
Random generator3 = new Random();
public void run() {
while (true) {
try {
Thread.sleep(50);
result3 = ((count3++) % 4);
textWindow3.setText(Integer.toString(result3));
} catch (InterruptedException e) {
// System.err.println("Interrupted.");
int randomInt3 = generator3.nextInt(75);
for (int i = 0; i < randomInt3; i++) {
try {
Thread.sleep(50);
} catch (InterruptedException e1) {
System.err.println("Interrupted.");
}
result3 = (count3++) % 4;
textWindow3.setText(Integer.toString(result3));
}
break;
}
}
}
}
private class ToggleButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("Stop")) {
counter1Thread.interrupt();
counter2Thread.interrupt();
counter3Thread.interrupt();
toggleButton.setLabel("Wait");
try {
counter1Thread.join();
counter2Thread.join();
counter3Thread.join();
} catch (InterruptedException e1) {
System.err.println("Interrupted.");
}
if ((result1 == result2) && (result2 == result3)) {
resultWindow.setText("You Win!");
} else {
resultWindow.setText("Sorry, You Lose!");
}
toggleButton.setLabel("Start");
}
else if (e.getActionCommand().equals("Start")) {
counter1Thread.start();
counter2Thread.start();
counter3Thread.start();
toggleButton.setLabel("Stop");
resultWindow.setText("");
}
}
}
}
This is the error I receive:
Exception in thread "AWT-EventQueue-0" java.lang.IllegalThreadStateException
at java.lang.Thread.start(Unknown Source)
at SlotMachine$ToggleButtonListener.actionPerformed(SlotMachine.java:166)
at java.awt.Button.processActionEvent(Unknown Source)
at java.awt.Button.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
