@Override
public void update(GameContainer gc, int delta) throws SlickException {
myUpdate(delta);
}

public void myUpdate(int delta) {            
tmpY = body.getBounds().getY();
tmpY += gravity.y * body.acceleration * delta;
body.getBounds().setY(tmpY);
}

endPos.set((float)(x + width * Math.cos(Math.toRadians(rotation))), (float)(y + width * Math.sin(Math.toRadians(rotation))));

   <object type="application/x-java-applet" height="600" width="800">
     <param name="code" value="G.class" />
     <param name="archive" value="jar/game.pack.gz" />
     <param name="java_arguments" value="-Djnlp.packEnabled=true"/>
   </object>

   
<object type="application/x-java-applet" height="600" width="800">
     <param name="code" value="G.class" />
     <param name="archive" value="game.pack.gz" />
     <param name="java_arguments" value="-Djnlp.packEnabled=true"/>
     Applet failed to run.  No Java plug-in was found.
   </object>

   public void run() {
      final int MAX_FRAME_SKIPS = 5;
      final int NO_DELAYS_PER_YIELD = 16;
      final int TARGET_FPS = 60;
      final long OPTIMAL_TIME = 1000000000 / TARGET_FPS;

      long beforeTime, afterTime, timeDiff, sleepTime;
      long overSleepTime = 0L;
      long excess = 0L;
      long period = 1000 / TARGET_FPS;

      int noDelays = 0;
      int fps = 0;
      int lastFpsTime = 0;
      
      double delta = 1.0;
      
      beforeTime = System.nanoTime();
      isRunning = true;

      while (isRunning) {
         update(delta);
         render();
         paintScreen();

         afterTime = System.nanoTime();
         timeDiff = afterTime - beforeTime;
         sleepTime = (period - timeDiff) - overSleepTime;
         
         delta = timeDiff / ((double) OPTIMAL_TIME);
         
         lastFpsTime += timeDiff;
         fps++;

         if (lastFpsTime >= 1000000000) {
            printFps = fps;
            lastFpsTime = 0;
            fps = 0;
         }

         if (sleepTime > 0) {
            try {
               Thread.sleep(sleepTime / 1000000L);
            } catch (InterruptedException e) {
               e.printStackTrace();
            }
            
            overSleepTime = (System.nanoTime() - afterTime) - sleepTime;
            
         } else {
            excess -= sleepTime;
            overSleepTime = 0L;

            if (++noDelays >= NO_DELAYS_PER_YIELD) {
               Thread.yield();
               noDelays = 0;
            }
         }

         beforeTime = System.nanoTime();

         int skips = 0;

         while ((excess > period) && (skips < MAX_FRAME_SKIPS)) {
            excess -= period;
            update(delta);
            skips++;
         }
      }

   }