[JAVA]loop movimento

[esploratore8]

Ciao a tutti ,qualcuno sa come far ripetere all infinito il movimento dall alto al basso(e non viceversa) delle immagini??? P.S se avete bisogno posto anche le altre classi.

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Characters extends Thread {
   private int x;
   private int y;
   private JPanel frame;
   private Image im;
   public Characters(int a,int b) {
      x = a;
      y = b;
   }
   
   public Characters(int i, int j, JPanel frame,String path) {
      this(i,j);
      this.frame = frame;
      im = Toolkit.getDefaultToolkit().getImage (path);
   }

   @Override
   public void run() {
      for (int i = 0; i < 24; i = i + 1) {
         
          y += i;
        
         try {
            Thread.sleep(200,i);
            
         } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         }
      }
   
   }

   public void draw(Graphics graphics){
      graphics.setColor(Color.BLACK);
      
      //qui metti l imagel
      //graphics.drawImage(.....)
      graphics.drawImage(im, x, y,frame);
   }
   
}