I got this error, when the bullet collides with the enemy.
341, 458 null
341, 458 null
341, 458 null
341, 456 java.awt.Rectangle[x=340,y=75,width=50,height=50]
341, 456 java.awt.Rectangle[x=325,y=45,width=50,height=50]
341, 456 java.awt.Rectangle[x=479,y=15,width=50,height=50]
341, 454 java.awt.Rectangle[x=340,y=76,width=50,height=50]
<CUT THIS OUT. ABOUT 1000 LINES LIKE THE ONES ABOVE>
305, 352 java.awt.Rectangle[x=222,y=36,width=50,height=50]
305, 352 java.awt.Rectangle[x=299,y=6,width=50,height=50]
341, 234 java.awt.Rectangle[x=340,y=186,width=50,height=50]
Exception in thread "AWT-EventQueue-0" java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
at java.util.AbstractList$Itr.next(Unknown Source)
at Draw.run(Draw.java:179)
at java.lang.Thread.run(Unknown Source)
at Draw.actionPerformed(Draw.java:139)
at javax.swing.Timer.fireActionPerformed(Unknown Source)
at javax.swing.Timer$DoPostEvent.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$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)I have never seen this error before. What could cause it. Here is my code that it occurs in
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.io.IOException;
import javax.swing.*;
import java.util.*;
import javax.imageio.*;
import javax.swing.Timer;
public class Draw extends JPanel implements ActionListener, KeyListener, Runnable{
Draw drawing;
Vector<Enemy> enemy = new Vector<Enemy>();
Vector<Point> enbullets = new Vector<Point> ();
Vector<Point> bullets = new Vector<Point> ();
Image playerBullet, enBullet, playerShip;
Thread thread = new Thread(this);
Timer t = new Timer (20, this);
int px = 225, py = 450;
Rectangle pRect;
int shootTimer = 0;
boolean shootAvailable = true;
int lives = 5;
boolean up, down, left, right;
int enTimer;
public void startDraw(Draw d){
grabFocus();
drawing = d;
try{
playerBullet = ImageIO.read(new File ("Images/playerBullet.png"));
enBullet = ImageIO.read(new File ("Images/enBullet.png"));
playerShip = ImageIO.read (new File ("Images/playerShip.png"));
}catch (IOException e){
e.printStackTrace();
}
addKeyListener (this);
repaint();
t.start();
}
public void createEnemy(){
Enemy en = new Enemy ();
enemy.add (en);
en.sendDrawing(drawing);
}
public void paintComponent (Graphics g){
super.paintComponent (g);
for (Enemy en : enemy){
g.drawImage(en.enImage, en.enx, en.eny, 50, 50, this);
}
g.drawImage(playerShip, px, py, 50, 50, this);
for (Point b : bullets){
g.drawImage(playerBullet,b.x + 22, b.y + 10, 5, 10, this);
}
for (Point b : enbullets){
g.drawImage(enBullet,b.x + 22, b.y, 5, 10, this);
}
}
public void enemyShot(int enx, int eny) {
// TODO Auto-generated method stub
}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
int key = e.getKeyCode();
if (key == KeyEvent.VK_UP){
up = true;
}
if (key == KeyEvent.VK_DOWN){
down = true;
}
if (key == KeyEvent.VK_LEFT){
left = true;
}
if (key == KeyEvent.VK_RIGHT){
right = true;
}
if (key == KeyEvent.VK_SPACE && shootAvailable == true){
bullets.add (new Point (px + 10,py + 10));
shootAvailable = false;
}
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
int key = e.getKeyCode();
if (key == KeyEvent.VK_UP){
up = false;
}
if (key == KeyEvent.VK_DOWN){
down = false;
}
if (key == KeyEvent.VK_LEFT){
left = false;
}
if (key == KeyEvent.VK_RIGHT){
right = false;
}
}
@Override
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
shootTimer += 20;
enTimer += 20;
if (shootTimer % 500 == 0){
shootAvailable = true;
shootTimer = 0;
}
if (enTimer == 600){
Enemy en = new Enemy ();
enemy.add(en);
enTimer = 0;
}
thread.run();
}
// collision detection
public void run() {
// TODO Auto-generated method stub
if (up == true){
py -= 2;
}
if (down == true){
py += 2;
}
if (left == true){
px -= 2;
}
if (right == true){
px += 2;
}
pRect = new Rectangle (px,py,50,50);
repaint();
for (Enemy en : enemy){
en.eny += 1;
}
for (Point b : bullets){
b.y -= 2;
}
for (Point enb : enbullets){
enb.y += 2;
}
for (Point p : enbullets){
if (pRect.contains (p.x+5, p.y+10)){
lives -= 1;
}
}
for (Point p : bullets){
for (Enemy enm: enemy){
System.out.println (p.x + ", " + p.y + "\t " + enm.enRect);
if (enm.getRect().contains (p.x + 5, p.y)){
enemy.remove(enm);
}
}
}
}
}Thanks for any help