Unable to send a byte to a Servlet

Question

Hello,
I am trying to execute a simple example of HTTP communication found in the Carol Hammer's book "Creating Mobile Games". I can send data from the servlet to the midlet, but i cannot send a single byte from the midlet to the servlet.
I am using WTK version 2.2 for the devlopment and Tomcat 5.5.17 for running the servlet (in localhost)
Here is the (partial) code of the midlet :
public void communicationWithServlet() {
HttpConnection connection = null;
DataOutputStream dos = null;
DataInputStream dis = null;
try {
connection = (HttpConnection)Connector.open(SERVER_URL);
((HttpConnection)connection).setRequestMethod(HttpConnection.POST);
int rc = connection.getResponseCode();
if (rc != HttpConnection.HTTP_OK) {
throw new IOException("HTTP response code: " + rc);
     dos = connection.openDataOutputStream();
     System.out.println("before");
     dos.write((byte)100);
     System.out.println("after");
     dos.flush();
dis = connection.openDataInputStream();
     byte[] data = new byte[10];
     dis.readFully(data);
     message = new String(data);
     System.out.println(message);
} catch(Exception e) { }
finally {
try {
if(dis != null) { dis.close();}
if(connection != null) {connection.close();}
     catch(Exception e) {}
The midlet is blocked by the instruction : dos.write((byte)100);
Here is the code of the servlet :
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class SimpleServlet extends HttpServlet {
     public void doPost(HttpServletRequest requete, HttpServletResponse reponse)
          throws ServletException, IOException {
               InputStream is = requete.getInputStream();
               int data= is.read();
               reponse.setContentType("text/html");
               PrintWriter out = reponse.getWriter();
               out.println("Hello");
               out.close();
Many thanks in advance for your help

Answer 1

If I delete the following lines :
int rc = connection.getResponseCode();
if (rc != HttpConnection.HTTP_OK) {
throw new IOException("HTTP response code: " + rc);
my problem is solved : the byte is sent to the servlet
But I would understand : why the call to the getResponseCode method prevents the midlet to send the byte to the servlet ?
Thanks for your help