Thread: Images works on an applet, but doesn't work when an applet is in a JFrame.

i understand that, but can't figure out, how to load images only once.

i do load same image for all blocks. and sometimes when the ball hits a block, errors appears:

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 Zaidimas.Main.paint(Main.java:229)
	at Zaidimas.Main.update(Main.java:189)
 
	at sun.awt.RepaintArea.updateComponent(Unknown Source)
	at sun.awt.RepaintArea.paint(Unknown Source)
	at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(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.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$2.run(Unknown Source)
	at java.awt.EventQueue$2.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)

My paint method:

public void paint(Graphics g){
//background
		try {
			url_bg = getClass().getResource("bg.png");
			bg = ImageIO.read(url_bg);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		g.drawImage(bg, 0, 0, this);
 
//ball		
		ball.Draw(g);
 
//paddle
 
		try {
			url_paddle = getClass().getResource("paddle.png");
			paddle = ImageIO.read(url_paddle);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		g.drawImage(paddle, paddle.x, paddle.y, this);
 
//blocks
 
		for(Block b : blocks){
			b.draw(g);
			try {
				url_block = getClass().getResource("block.png");
				block = ImageIO.read(url_block);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			g.drawImage(block, b.x, b.y, this);
 
		}

My update method (find this on youtube, to reduce/remove flickering in an applet):

private Image dbImage;	
private Graphics dbGraphics;
 
public void update(Graphics g){
		if (dbImage == null)
		{
			dbImage = createImage(this.getSize().width, this.getSize().height);
			dbGraphics = dbImage.getGraphics();
		}
 
		dbGraphics.setColor(this.getBackground());
		dbGraphics.fillRect(0, 0, this.getSize().width, this.getSize().height);
 
		dbGraphics.setColor(this.getForeground());
		paint(dbGraphics);
		g.drawImage(dbImage, 0, 0, this);
 
	}

ok, done, this one is SOLVED.
Big thanks to Norm.