Somethings wrong with my drawImage

 public void paintComponent(Graphics g){
        	g = f.getGraphics();
        	Graphics2D g1 = (Graphics2D)g;
        	g.drawImage(bg,0,0,null);
        	while(isRunning){
    			try{
    				for(int i = 0; i < living.size(); i++){
    				Spawn s = living.get(i);	
    				int x = (int) s.getX();
    				int y = (int) s.getY();
    				g1.drawImage(s.getImage(), x,y,null);
    			
    				}
    				 
    			Thread.sleep(15);
    			}catch(Exception ex){
    				
    			}
    		}
         }