Menu
import javax.swing.* ;
import java.awt.* ;
import java.awt.event.*;

public class Menu extends JFrame implements ActionListener{
private JFrame jfbase ;
private JFrame jfnbplayeur ;
private MenuJoueur mj;

public Menu(){
jfbase = new JFrame ("Menu du jeu");

JPanel jp =new JPanel();
jp.setBackground(Color.BLACK);
jp.setPreferredSize(new Dimension (280,320));
JButton jbstart = new JButton("Start");
jbstart.addActionListener(this);
jp.add(jbstart);
JButton jbexit = new JButton("Exit");
jbexit.addActionListener(this);
jp.add(jbexit);

jfbase.setContentPane(jp);//change le panneau de contenu
jfbase.pack();//réglage de la taille par le contenu
jfbase.setVisible(true);
}

public void actionPerformed(ActionEvent ae){
JButton jb = (JButton)ae.getSource();
if(jb.getText().equals("Start")){
mj = new MenuJoueur();
jfbase.dispose();
}
else if(jb.getText().equals("Exit")){
System.exit(0);
}
}
}

Menu Joueur
import javax.swing.* ;
import java.awt.* ;
import java.awt.event.*;

public class MenuJoueur extends JFrame implements ActionListener{
private JFrame jfbase ;
private JFrame jfnbplayeur ;
private Menu mn;
private yourclass yc;

public MenuJoueur(){
jfnbplayeur = new JFrame ("Nombre de joueur");

JPanel jp =new JPanel();
jp.setPreferredSize(new Dimension (165,130));
JButton jbdeux =new JButton("Deux Joueur");
jbdeux.addActionListener(this);
jp.add(jbdeux);
JButton jbtrois =new JButton("Trois joueurs (en DLC)");
jbtrois.addActionListener(this);
jp.add(jbtrois);
JButton jbquatre =new JButton("Quatre joueurs (en DLC)");
jbquatre.addActionListener(this);
jp.add(jbquatre);
JButton jbannuler =new JButton("Annuler");
jbannuler.addActionListener(this);
jp.add(jbannuler);

jfnbplayeur.setContentPane(jp);//change le panneau de contenu
jfnbplayeur.pack();//réglage de la taille par le contenu
jfnbplayeur.setVisible(true);
}

public void actionPerformed(ActionEvent ae){
JButton jb = (JButton)ae.getSource();
if(jb.getText().equals("Deux Joueur")){
new yourclass().run();
jfbase.dispose();
}
else if(jb.getText().equals("Trois joueurs")){

jfbase.dispose();
}
else if(jb.getText().equals("Quatre joueurs")){

jfbase.dispose();
}
else if(jb.getText().equals("Annuler")){
mn = new Menu() ;
jfbase.dispose();
}
}
}

YourClass
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Stroke;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.ArrayList;
import javax.swing.* ;
import java.awt.* ;
import java.awt.event.*;

public class yourclass extends Core implements KeyListener, MouseListener,
MouseMotionListener, ActionListener {
int centrex1 = 0;
int centrey1 = 500;
int centrex2 = 1700;
int centrey2 = 500;
int currentDirection1 = 1;
int currentDirection2 = 3;
int moveAmount = 5;
ArrayList<Integer> pathx1 = new ArrayList();
ArrayList<Integer> pathy1 = new ArrayList();
ArrayList<Integer> pathx2 = new ArrayList();
ArrayList<Integer> pathy2 = new ArrayList();
private JFrame jffinpartie;
// private JFrame jffinpartie2;
// private JFrame jffinpartie3;

public void init() {
super.init();

Window w = sm.getFullScreenWindow();
w.addKeyListener(this);
w.addMouseListener(this);
w.addMouseMotionListener(this);
}

public static void main(String[] args) {
new yourclass().run();
}

public void draw(Graphics2D g) {
switch(currentDirection1){
case 0:
if (centrey1>0){
centrey1-=moveAmount;
} else {
centrey1 = sm.getHeight();
}
break;
case 1:
if (centrex1 < sm.getWidth()){
centrex1+=moveAmount;
} else {
centrex1 = 0;
}
break;
case 2:
if (centrey1 < sm.getHeight()){
centrey1+=moveAmount;
} else {
centrey1 = 0;
}
break;
case 3:
if (centrex1>0){
centrex1-=moveAmount;
} else {
centrex1 = sm.getWidth();
}
break;
}
switch(currentDirection2){
case 0:
if (centrey2>0){
centrey2-=moveAmount;
} else {
centrey2 = sm.getHeight();
}
break;
case 1:
if (centrex2 < sm.getWidth()){
centrex2+=moveAmount;
} else {
centrex2 = 0;
}
break;
case 2:
if (centrey2 < sm.getHeight()){
centrey2+=moveAmount;
} else {
centrey2 = 0;
}
break;
case 3:
if (centrex2>0){
centrex2-=moveAmount;
} else {
centrex2 = sm.getWidth();
}
break;
}

if ((centrex1 == centrex2) && (centrey1 == centrey2) ) {
finPartie("Ex-aequo");

}

for (int x = 0;x<pathx1.size();x++){
if (((centrex1 == pathx1.get(x)) && (centrey1 == pathy1.get(x))) || ((centrex1 == pathx2.get(x)) && (centrey1 == pathy2.get(x)))) {
finPartie("rouge");

}

if (((centrex2 == pathx2.get(x)) && (centrey2 == pathy2.get(x))) || ((centrex2 == pathx1.get(x)) && (centrey2 == pathy1.get(x)))){
finPartie("bleu");

}
}
pathx1.add(centrex1);
pathy1.add(centrey1);
pathx2.add(centrex2);
pathy2.add(centrey2);
g.setColor(Color.BLACK);
g.fillRect(0, 0, sm.getWidth(), sm.getHeight());
for (int x = 0;x<pathx1.size();x++){
g.setColor(Color.blue);
g.fillRect(pathx1.get(x), pathy1.get(x), 10, 10);
g.setColor(Color.red);
g.fillRect(pathx2.get(x), pathy2.get(x), 10, 10);
}

}//fin draw

public void finPartie(String s){
this.stop();
jffinpartie = new JFrame (s);

JPanel jp =new JPanel();
jp.setPreferredSize(new Dimension (165,130));
JButton jbnewgame =new JButton("Nouvelle partie");
jbnewgame.addActionListener(this);
jp.add(jbnewgame);
JButton jbendgame =new JButton("Menu");
jbendgame.addActionListener(this);
jp.add(jbendgame);

jffinpartie.setContentPane(jp);//change le panneau de contenu
jffinpartie.pack();//réglage de la taille par le contenu
jffinpartie.setVisible(true);

}

public void actionPerformed(ActionEvent ae){
JButton jb = (JButton)ae.getSource();
if(jb.getText().equals("Nouvelle partie")){
new yourclass().run();
jffinpartie.dispose();
}
else if(jb.getText().equals("Menu")){
new Menu();
jffinpartie.dispose();
}

}

public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_UP) {
if (currentDirection2 != 2){
currentDirection2 = 0;
}
} else if (e.getKeyCode() == KeyEvent.VK_DOWN) {
if (currentDirection2 != 0){
currentDirection2 = 2;
}
} else if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
if (currentDirection2 != 3){
currentDirection2 = 1;
}
} else if (e.getKeyCode() == KeyEvent.VK_LEFT) {
if (currentDirection2 != 1){
currentDirection2 = 3;
}
}
if (e.getKeyCode() == KeyEvent.VK_Z){
if (currentDirection1 != 2){
currentDirection1 = 0;
}
} else if (e.getKeyCode() == KeyEvent.VK_S) {
if (currentDirection1 != 0){
currentDirection1 = 2;
}
} else if (e.getKeyCode() == KeyEvent.VK_D) {
if (currentDirection1 != 3){
currentDirection1 = 1;
}
} else if (e.getKeyCode() == KeyEvent.VK_Q) {
if (currentDirection1 != 1){
currentDirection1 = 3;
}
}
}

public void keyReleased(KeyEvent e) {

}

public void keyTyped(KeyEvent arg0) {

}

public void mouseClicked(MouseEvent e) {

}

public void mouseEntered(MouseEvent arg0) {
}

public void mouseExited(MouseEvent arg0) {
}

public void mousePressed(MouseEvent e) {
}

public void mouseReleased(MouseEvent e) {
}

public void mouseDragged(MouseEvent e) {

}

public void mouseMoved(MouseEvent e) {

}
}

Core
import java.awt.*;
import java.awt.image.BufferedImage;

public abstract class Core {

private static final DisplayMode modes[] =
{
//new DisplayMode(1920,1080,32,0),
new DisplayMode(1680,1050,32,0),
//new DisplayMode(1280,1024,32,0),
new DisplayMode(800,600,32,0),
new DisplayMode(800,600,24,0),
new DisplayMode(800,600,16,0),
new DisplayMode(640,480,32,0),
new DisplayMode(640,480,24,0),
new DisplayMode(640,480,16,0),
};
private boolean running;
protected ScreenManager sm;

public void stop(){
running = false;
}

public void run(){
try{
init();
gameLoop();
}finally{
sm.restoreScreen();
}
}

public void init(){
sm = new ScreenManager();
DisplayMode dm = sm.findFirstCompatibaleMode(modes);
sm.setFullScreen(dm);
Window w = sm.getFullScreenWindow();
w.setFont(new Font("Arial",Font.PLAIN,20));
w.setBackground(Color.WHITE);
w.setForeground(Color.RED);
w.setCursor(w.getToolkit().createCustomCursor(new BufferedImage(3, 3, BufferedImage.TYPE_INT_ARGB), new Point(0, 0),"null"));
running = true;
}

public void gameLoop(){
long startTime = System.currentTimeMillis();
long cumTime = startTime;

while (running){
long timePassed = System.currentTimeMillis()-cumTime;
cumTime+= timePassed;
update(timePassed);
Graphics2D g = sm.getGraphics();
draw(g);
g.dispose();
sm.update();

try{
Thread.sleep(20);
}catch(Exception ex){}
}
}

public void update(long timePassed){}

public abstract void draw(Graphics2D g);

}

ScreenManager
import java.awt.*;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;

public class ScreenManager {

private GraphicsDevice vc;

public ScreenManager(){
GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
vc = e.getDefaultScreenDevice();
}

public DisplayMode[] getCompatibleDisplayModes(){
return vc.getDisplayModes();
}

public DisplayMode findFirstCompatibaleMode(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;
}

public DisplayMode getCurrentDM(){
return vc.getDisplayMode();
}

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;
}

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);
}
}

public Graphics2D getGraphics(){
Window w = vc.getFullScreenWindow();
if(w != null){
BufferStrategy bs = w.getBufferStrategy();
return (Graphics2D)bs.getDrawGraphics();
}
else{
return null;
}
}

public void update(){
Window w = vc.getFullScreenWindow();
if(w != null){
BufferStrategy bs = w.getBufferStrategy();
if(!bs.contentsLost()){
bs.show();
}
}
}

public Window getFullScreenWindow(){
return vc.getFullScreenWindow();
}

public int getWidth(){
Window w = vc.getFullScreenWindow();
if(w != null){
return w.getWidth();
}else{
return 0;
}
}

public int getHeight(){
Window w = vc.getFullScreenWindow();
if(w != null){
return w.getHeight();
}else{
return 0;
}
}

public void restoreScreen(){
Window w = vc.getFullScreenWindow();
if(w != null){
w.dispose();
}
vc.setFullScreenWindow(null);
}

public BufferedImage createCompatibaleimage(int w, int h, int t){
Window win = vc.getFullScreenWindow();
if(win != null){
GraphicsConfiguration gc = win.getGraphicsConfiguration();
return gc.createCompatibleImage(w,h,t);
}else{
return null;
}

}

}