Snake Game in Java

screen.java is using for fullscreen game develpment

import java.awt.*;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
//import java.lang.reflect.InvocationTargetException;
import javax.swing.JFrame;
public class screen {

 private GraphicsDevice vc;
 
 //give vc access to monitor screen
 //Constructor
 public screen(){
  
  GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
  vc = e.getDefaultScreenDevice();
  
 }
 //get all compatible DM
 public DisplayMode[] getCompatibleDisplayModes(){
  return vc.getDisplayModes();
 }
 
 //compares DM passed in to vc DM and see if they matchs
 public DisplayMode findFirstCompatibleMode(DisplayMode modes[]){
  
  DisplayMode goodModes[] = vc.getDisplayModes();
  for(int x=0;x<modes.length;x++){
   for(int y=0;y<goodModes.length;y++){
    if(displayModesMatch(modes[x],goodModes[y])){
     return modes[x];
    }
   }
  }
  return null;
 }
 //get current DM 
 public DisplayMode getCurrentDisplayMode(){
  return vc.getDisplayMode();
 }
 
 //check if two modes match each other
 public boolean displayModesMatch(DisplayMode m1,DisplayMode m2){
  if(m1.getWidth() != m2.getWidth() || m1.getHeight() != m2.getHeight())
    return false;
  
  if(m1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI  && m2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI && m1.getBitDepth() != m2.getBitDepth())
   return false;
  
  if(m1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN && m2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN && m1.getRefreshRate() != m2.getRefreshRate())
   return false;
  return true;
 }
 
 //make frame full screen
 public void setFullScreen(DisplayMode dm){
  JFrame f = new JFrame();
  f.setUndecorated(true);
  f.setIgnoreRepaint(true);
  f.setResizable(false);
  vc.setFullScreenWindow(f);
  
  if(dm != null && vc.isDisplayChangeSupported()){
   try{
    vc.setDisplayMode(dm);
   }catch(Exception ex){} 
  }
  f.createBufferStrategy(2);
 }
 //we will set graphics object equal to this
 public Graphics2D getGraphics(){
  
  Window w = vc.getFullScreenWindow();
  if(w != null){
   BufferStrategy s = w.getBufferStrategy();
   return (Graphics2D)s.getDrawGraphics();
  }else{
   return null;
  }
  
 }
 //update display
 public void update(){
  Window w =vc.getFullScreenWindow();
  if(w != null){
   BufferStrategy s = w.getBufferStrategy();
   if(!s.contentsLost()){
    s.show();
   }
  }
 }
 //return full screen window
 public Window getFullScreenWindow(){
  return vc.getFullScreenWindow();
 }
 //get witdh of window
 public int getWidth(){
  Window w = vc.getFullScreenWindow();
  if(w != null)
   return w.getWidth();
  else 
   return 0;
 }
 
 
 //get height of window
 public int getHeight(){
   Window w = vc.getFullScreenWindow();
   if(w != null)
    return w.getHeight();
   else 
    return 0;
 }
 // get out of fullscreen
 public void restoreScreen(){
  Window w = vc.getFullScreenWindow();
  if(w != null)
   w.dispose();
  vc.setFullScreenWindow(null);
 }
 
 //create image compatible with monitor
 public BufferedImage createCompatibleImage(int w,int h,int t){
  Window win =vc.getFullScreenWindow();
  if(win != null){
   GraphicsConfiguration gc = win.getGraphicsConfiguration();
   return gc.createCompatibleImage(w,h,t);
  }
  return null;
 }
 
}