Jsp beans problem

Question

hi all i have some trouble ...
i`m making a register form in jsp and i want to put the data into bean and then retrieve the data in a servlet
in the jsp i have:
<jsp:useBean id="data" class="DataBean">
<jsp:setProperty name="data" property="*"/>
</jsp:useBean>
<form method=post action="/SubmitServlet">
<input type=text name="message">
<input type=submit value="submit">
</form>
in the bean i have:
private String message = null;
public String getMessage() {
return message;
public void setMessage(String string) {
message = string;
and in the servlet:
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
HttpSession session = req.getSession();
     DataBean adr = (DataBean)session.getAttribute("data");
     if (adr==null) {
          System.out.println("ada");
     else {
     System.out.println(adr.getMessage());
.... and the server prints me the null string ... so the bean is not updated when i`m submiting the information from the jsp to the servlet ....
how could i make it right?

Answer 1

Oh, I see, when you said 'the Servlet prints the null string', you meant it gets to this line:
System.out.println(adr.getMessage());
and prints "null", right?
Well, that is because you never set the message. The way your JSP works:
1) Create a DataBean and store it in session (are there paramameters? no, so don't call any set methods)
2) Display a Form.
Then when the User presses the submit button, you have an action set to the Servlet /SubmitServlet, not back to the JSP. So, the Servlet has to handle the parameters passed from the form, not JSP. The JSP is done after it displays the page.
public void doPost(...) ...
  HttpSession session = req.getSession();
  DataBean adr = (DataBean)session.getAttribute("data");
  if (adr==null) {
    adr = new DataBean();
    session.setAttribute("data", adr);
  String message = req.getParameter("message");
  adr.setMessage(message);
  System.out.println("The Message Is: "+message);
  //Maybe do a forward?? or some display??
}If you want the JSP to handle the parameters sent by the form, then you will have to make the form's action set to the same address, not to the servlet (see my message in the first reply about how to make sure the setProperty gets called...)