read and write on same /dev/tty ?

Hi,

I could write to an /dev/pty, but i could not read datas on same tty,
receive message Bad File Descriptor ?
Anyone has na idea ?

Regards
Philippe


im****t java.io.*;

public class Class15
{
 String ****tName=null;
 FileOutputStream fos2 = null;
 FileInputStream fis2 = null;


        public byte[] toBytes(char[] from) {
          byte[] result = new byte[from.length];

          for (int i = 0; i < from.length; i++) {
            result[i] = (byte)from[i];
          }

          return result;
        }




  public Class15(String m****tName) throws Exception
  {
                      ****tName=m****tName;

           System.out.println("cl01 ****tName "+****tName);



                  fos2 = new FileOutputStream(****tName);

                      System.out.println("cl02 ****tName "+****tName);

                    //  fis2 = new FileInputStream(****tName); // Ne
fonctionne pas
                      FileDescriptor fd = fos2.getFD();
                      fis2 = new FileInputStream(fd);
                      //fis2 = new FileInputStream(fd.in);
                      System.out.println("cl03 ****tName "+****tName);

                      System.out.println("cl04 ****tName fis2
"+fis2.available());

                  }

public void go(String xx)
{

                  try{
                     fos2.write(toBytes(xx.toCharArray()));
                     fos2.write('\n');
                     fos2.flush();

           //   fos2.close();
              } catch(Exception e)
                {
                System.out.println("Erreur1 "+e.getMessage());

                }

  }




      public String read(){
      String rt=null;
      try{
          System.out.println("r01 *"+****tName+"*");

                               System.out.println("r03 available
*"+fis2.available());
                               System.out.println("r04 valid
*"+fis2.getFD().valid());

            while (true) {

                      System.out.println("r05 *"+****tName+"*");
                    byte b[] = new byte[100];
                    // Read some data from the modem.
                    int nbytes = fis2.read(b);
                    System.out.println("r06 *"+nbytes+"*");


                    System.out.println (new String (b, 0, nbytes));
                  }
      }
      catch(Exception e1){
      System.out.println(e1.getMessage());

      }



            return rt;
        }



    public void close() {
    try{
        fos2.close();
        fis2.close();
    }catch(Exception e1){}
    }


  /**
   *
   * @[EMAIL PROTECTED]
 args
   */
  public static void main(String[] args)
  {
      String ****tName=new String("/dev/ptyqf");
       String xx=new String("COUCOU DE JAVA"); // Demande de l'Heure

      if(args.length>0)
       ****tName = args[0]; // ex /dev/ttyq0
       try{
      Class15 x=new Class15(****tName);

      System.out.println("****T OUVERT, lancer le BASIC avant de
Valider!");
      System.out.println("APPUYER SUR ENTREE pour l'envoi");

      System.out.println("fis2 "+x.fis2.available());


      //Lecture du clavier
      BufferedReader entree=new BufferedReader(new
InputStreamReader(System.in));

      while(entree.readLine()!=null &&
!entree.readLine().equalsIgnoreCase("f"))
      {
      System.out.println("GO");

          System.out.println("fis2B "+x.fis2.available());
      x.go(xx);
          System.out.println("fis2c "+x.fis2.available());


      //Test de lecture depuis le BASIC sur le pty
       String lu=x.read();
       System.out.println("LU depuis le BASIC "+lu);

      }
       System.out.println("FERMETURE DU FLUX!");
        x.close();
      }
       catch(Exception e1){System.out.println(e1.getMessage());}
  } 
  }