Look at http://processing.org/reference/ particularly the saveStrings() function.

Thank you for that answer, now I have another problem at the beginning of my sketch I declare two variables: "control" and "control1" which are sent by the serial port, but in the void keyPressed () and void actionPerformed (GUIEvent e) upon request the values ​​are not changed. And I do not arive to find the problem, here is my code:

1. /*
   avant = 1
   ariere = 2
   gauche = 3
   droite = 4
   stop = 5
   auto = 6
   manuelle = 7
   
   */
   
   
   
   
   import interfascia.*;
   import processing.serial.*;
   Serial port;
   
   
   GUIController c;
   
   IFButton av, ar, g, d, s, a, m;
   
   
   
   int controle ;
   int controle1 ;
   
   
   
   
   void setup() {
    
     size(600, 600);
     String portName = Serial.list()[0];
     port = new Serial(this, portName, 9600);
     port.bufferUntil('\n');
     println("connecter");
    
    
    
     background(155);
    
     c = new GUIController (this);
    
    
     av = new IFButton ("Avant", 250, 130, 80, 80);
     ar = new IFButton ("Ariere", 250, 370, 80, 80);
     g = new IFButton ("Gauche", 130, 250, 80, 80);
     d = new IFButton ("Droite", 370, 250, 80, 80);
     s = new IFButton ("Stop", 250, 250, 80, 80);
     a = new IFButton ("Automatique", 15, 550, 80, 30);
     m = new IFButton ("Manuelle", 100, 550, 80, 30);
    
    
    
   
     av.addActionListener(this);
     ar.addActionListener(this);
     g.addActionListener(this);
     d.addActionListener(this);
     s.addActionListener(this);
     a.addActionListener(this);
     m.addActionListener(this);
   
     c.add (av);
     c.add (ar);
     c.add (g);
     c.add (d);
     c.add (s);
     c.add (a);
     c.add (m);
   
    
   }
   
   
   
   
   void draw() {
        println("avant envoie :");
        println("controle : " + controle);
        println("controle1 : " + controle1);
        println("..........................................................................................");
        port.write(controle1);
        port.write(controle);
        println(" ");
        println("envoyer :");
        println("controle : " + controle);
        println("controle1 : " + controle1);
        println(":::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::");
        
       
   }
   
   
   
   
   
   
   
   //Debut commande au clavier
   void keyPressed(){
    
      if (keyCode == UP)
     {
       println("AVANT");
       int controle = 1;
       println("commande " + controle);
      
     
      
   
     }
     else if (keyCode == DOWN) {
       int controle = 2;
       println("commande " + controle);
       println("ARIERE");
      
    
      
   
     }
     else if (keyCode == LEFT) {
       int controle = 3;
       println("commande " + controle);
       println("GAUCHE");
   
      
   
     }
     else if (keyCode == RIGHT) {
       int controle = 4;
       println("commande " + controle);
       println("DROITE");
      
      
   
     }
     else if (key == 'a') {
       int controle1 = 6;
       println("commande1 " + controle);
       println("Automatique");
      
      
   
     }
     else if (key == 'm') {
       int controle1 = 7;
       println("commande1 " + controle1);
       println("Manuelle");
      
      
   
     }
     else{
      println("STOP");
      int controle = 5;
      println("commande " + controle1);
     
   
     }
       
    
   }
   //Fin commande au clavier
   
   
   
   
   
   
   //Debut commande a la sourie(écran)
   
   void actionPerformed (GUIEvent e) {
    
     if (e.getSource() == av)               //AV
     {
     
       println("Avant");
       int controle = 1;
       println("commande " + controle);
      
   
     }
    
     else if (e.getSource() == ar)          //AR
     {
      
       println("Arriere");
       int controle = 2;
       println("commande " + controle);
      
   
     }
    
     else if (e.getSource() == g)           //G
     {
      
       println("Gauche");
       int controle = 3;
       println("commande " + controle);
      
      
   
     }
    
     else if (e.getSource() == d)           //D
     {
      
       println("Droite");
       int controle = 4;
       println("commande " + controle);
     
      
      
   
     }
    
     else if (e.getSource() == s)           //S
     {
      
       println("Stop");
       int controle = 5;
       println("commande " + controle);
      
   
     }
     else if (e.getSource() == a)           //S
     {
      
       println("Automatique");
       int controle1 = 6;
       println("commande1 " + controle1);
      
      
   
     }
     else if (e.getSource() == m)           //S
     {
      
       println("Manuelle");
       int controle1 = 7;
       println("commande1 " + controle1);
      
      
     }
      
     
     }
     //Fin commande a la sourie(écran)
   
     //Envoi de la commande de controle
    
    
   
   

well…I can't test the whole code because I don't have such libraries…but.
simple point of start: (I advise you to simplify your code from the beginning to locate the first issues)

here's the first simple step:
is that what you want to achieve ?

1. 
    int controle = 9 ;
    int controle1 = 10 ;
   void setup()
   {
     size(500, 500);
   }
   
   void draw()
   {
   }
   
   void keyPressed() {
   
     if (keyCode == UP)
     {
       println("AVANT");
       controle = 1;
       println("commande " + controle);
     }
     else if (keyCode == DOWN) {
       controle = 2;
       println("commande " + controle);
       println("ARIERE");
     }
     else if (keyCode == LEFT) {
       controle = 3;
       println("commande " + controle);
       println("GAUCHE");
     }
     else if (keyCode == RIGHT) {
       controle = 4;
       println("commande " + controle);
       println("DROITE");
     }
     else if (key == 'a') {
       controle1 = 6;
       println("commande1 " + controle);
       println("Automatique");
     }
     else if (key == 'm') {
       controle1 = 7;
       println("commande1 " + controle1);
       println("Manuelle");
     }
     else {
       println("STOP");
       controle = 5;
       println("commande " + controle1);
     }
   }
   

i just pasted what you had
for instance variables must be initialized  once, no need to repeat "I'm an int I'm an int !!!!  I'm an int…!!!!"

" I'm an int I'm an int !!!!  I'm an int…!!!!"
Moreover, since you define controle1 inside a pair of braces {}, this variable (which is distinct from the one defined at the global level, and hides it), and its value, will just disappear as soon as the program flow goes outside of the closing brace...

Actually, it might be the core of your problem... To the point: remove the int part from the tests.