How to execute a servlet onload

Question

Hi everyone,
I am very new to servlets. I have a jsp page that calls a servlet which is executed on a submit button within a form.
It works, returning the data to the page. However I would like my servlet to be executed on load of the jsp. A tutorial that covers this area would be great.
If you have a suggestion please post a response.. Thanks.
<form name="data_form" method="post" action="Controller">
<input type="hidden" name="action" value="getData"/ >
</form>
public void doPost(HttpServletRequest request, HttpServletResponse response)
     throws ServletException, IOException {
          //String action = request.getServletPath().substring(1, request.getServletPath().indexOf("."));
          String action = (String)request.getParameter("action");
          // select application logic
          String target = null;
          try {
                               if(action.equals("getData")){                     
                    DataManager data = new DataManager();
                    request.setAttribute("Data", data.getData());
                    target = "/data.jsp";
                                 }catch(RuntimeException e){
               e.printStackTrace();
          }Edited by: _AlyssaK on May 29, 2009 8:49 AM                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

Onload? I've had a laugh, seriously :)
Create a Servlet class and implement doGet() wherein you do the desired loading tasks and finally forward the request to a JSP file and in the JSP file just access the loaded data through taglibs/EL. Finally map that servlet on an url-pattern and call it in your browser.
E.g. (semi pseudo)
doGet(request, response) {
    Data data = dataDAO.load();
    request.setAttribute("data", data);
    request.getRequestDispatcher("data.jsp").forward(request, response);
}data.jsp
<p>The data is: ${data}</p>web.xml
<servlet-mapping>
    <servlet-name>yourServlet</servlet-name>
    <url-pattern>/data</url-pattern>
</servlet-mapping>Then invoke it on [http://hostname:port/contextroot/data].