Hi All,
          I try a bluelet demo, I change some code here, I want to move
these codes of run()
========================================================
       out.writeUTF( "Boki Back Msg" );
       out.flush();
========================================================

to a soft key event, but it never work ( exception error is 0 / null )

public void commandAction(Command c, Displayable s) {
========================================================
       out.writeUTF( "Boki Back Msg" );
       out.flush();
========================================================
}

My original thread:

=============================================
 public void run()
 {

   StreamConnection c = null;
   try
   {
       localDevice = LocalDevice.getLocalDevice(); // obtain reference to
singleton
     localDevice.setDiscoverable(DiscoveryAgent.GIAC); // set Discover mode
to LIAC

String uuidString = "102030405060708090A0B0C0D0E0F010";
UUID uuid = new UUID(uuidString, false);

            String url = "btspp://localhost:" + uuid.toString()
+";name=Boki_SPP";

         server =  (StreamConnectionNotifier)Connector.open( url );
   localDevice.setDiscoverable(DiscoveryAgent.GIAC);

          ServiceRecord rec = localDevice.getRecord( server );

         rec.setAttributeValue( 0x0008, new DataElement(
DataElement.U_INT_1, 0xFF ) );

   } catch (Exception e)
   {

    System.out.println("try1 fail"+e.getMessage());
      System.out.println(e);
   }

   while( !done)
   {
     try {
                System.out.println("try2");

        c = server.acceptAndOpen();
          RemoteDevice rdev = RemoteDevice.getRemoteDevice( c );

          DataInputStream in = c.openDataInputStream();
       String s = in.readUTF();

       DataOutputStream out = c.openDataOutputStream();
========================================================
       out.writeUTF( "Boki Back Msg" );
       out.flush();
========================================================
       // close current connection, wait for the next one
     // c.close();

     } catch (Exception e)
     {
        System.out.println("try2 fail");
     }

   } // while

 }