display exception on formbackingobject

Hi all,
i want to display an exception occurred in the formbacking object.

new SimpleFormController.java

/*
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 * and open the template in the editor.
 */

package org.prova.spring;

import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.validation.BindException;
import org.springframework.validation.BindingErrorProcessor;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.SimpleFormController;
import org.springframework.web.util.WebUtils;

/** 
 *
 * @author AlfaOmega
 */
public class NewSimpleFormController extends SimpleFormController {

private String viewName;

public NewSimpleFormController() {
        //Initialize controller properties here or 
        //in the Web Application Context

//setCommandClass(MyCommand.class);
        //setCommandName("MyCommandName");
        //setSuccessView("successView");
        //setFormView("formView");
    }

@Override
    protected Object formBackingObject(HttpServletRequest request) throws Exception {

int i = 0;       
        List l = new ArrayList();
        WebUtils.exposeErrorRequestAttributes(request, new Exception(""), "dispatcher-servlet");
        BindException be = new BindException(l, "command");
        be.reject("SONO QUI!"); 
        return l;

}

@Override
    protected void onBindAndValidate(HttpServletRequest request,
                                 Object command,
                                 BindException errors)
                          throws Exception
    {
        errors.reject("SONO QUI!");
    }

@Override
    protected ModelAndView onSubmit(HttpServletRequest request, HttpServletResponse response, Object command, BindException errors) throws Exception {
        int i = 0;
        errors.reject("SONO QUI!");
        return super.onSubmit(request, response, command, errors);
    }

/**
     * @return the viewName
     */
    public String getViewName() {
        return viewName;
    }

/**
     * @param viewName the viewName to set
     */
    public void setViewName(String viewName) {
        this.viewName = viewName;
    }

//Use onSubmit instead of doSubmitAction 
    //when you need access to the Request, Response, or BindException objects
    /*
    @Override
    protected ModelAndView onSubmit(
            HttpServletRequest request, 
            HttpServletResponse response, 
            Object command, 
            BindException errors) throws Exception {
        ModelAndView mv = new ModelAndView(getSuccessView());
        //Do something...
        return mv;
    }
    */

}

try.jsp

<%-- 
    Document   : try
    Created on : 8-ago-2010, 12.24.24
    Author     : AlfaOmega
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ page session="true"%>
<%@ page import="java.util.List"%>
<%@ page import="java.util.Hashtable"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core_rt" %>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib uri="http://www.springframework.org/tags" prefix="spring" %>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1>Hello World!</h1>

<form:form commandName="command" action="try.htm" method="post">
                <div>
            <c:out value="${errors}"/>
                <span class="testo10">(*) Valorizzare uno dei campi di ricerca</span><br />
             <spring:hasBindErrors name="command">
         		<p class="ERROREROSSO">Ci sono ${errors.errorCount} errore/i in totale:</p>
		         <ul>
		            <c:forEach var="errMsgObj" items="${errors.allErrors}">
		               <li class="ERROREROSSO">
		                  <spring:message code="${errMsgObj.code}" text="${errMsgObj.defaultMessage}"/>
		               </li>
		            </c:forEach>
		         </ul>
      		</spring:hasBindErrors>
		</div>
                        <div id="box-button">
            <input type="submit" value="click me" name="click" />
        </div>
    </form:form>

</body>
</html>