Erro Struts+Ajax

Assuntos Gerais
#1

Olá Pessoal , estou rodando um exemplo de Struts+Ajax e estou com esse seguinte erro:

type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

javax.servlet.ServletException: Exception creating bean of class app.MyForm: {1}
	org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:848)
	org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:781)
	org.apache.jsp.pages.usuario_005fvalido_jsp._jspService(org.apache.jsp.pages.usuario_005fvalido_jsp:75)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

Abaixo vai minha classe:

App.MyForm

package app;

import org.apache.struts.action.ActionForm; 
  
public class MyForm extends ActionForm {   

protected String rssUrl;   
protected String categoria;   
protected String nameUser;
/**
 * @return the categoria
 */
public String getCategoria() {
	return categoria;
}
/**
 * @param categoria the categoria to set
 */
public void setCategoria(String categoria) {
	this.categoria = categoria;
}
/**
 * @return the nameUser
 */
public String getNameUser() {
	return nameUser;
}
/**
 * @param nameUser the nameUser to set
 */
public void setNameUser(String nameUser) {
	this.nameUser = nameUser;
}
/**
 * @return the rssUrl
 */
public String getRssUrl() {
	return rssUrl;
}
/**
 * @param rssUrl the rssUrl to set
 */
public void setRssUrl(String rssUrl) {
	this.rssUrl = rssUrl;
}  

  
 
}

Parte do Meu Struts Config


<form-beans>
	
<form-bean name="cadastroform" type="app.CadastroForm" />
<form-bean name="myForm" type="app.MyForm" />   

</form-beans>


<action path="/usuario_valido" type="app.UsuarioValidoAction" name="myForm" />   
  
	    <action path="/sub_categoria" type="app.SubCategoriaAction" name="myForm">   
			  <forward name="listSubCategoria" path="/pages/sub_categoria.jsp" />   
	    </action>   
  
	    <action path="/leitor_xml" type="app.LeitorXmlAction" name="myForm" />

Finalmente a .Jsp


<%@ taglib uri="/tags/struts-html" prefix="html" %>   
<html:html>   
<head>   
<title>Usuário Válido</title>   
<script type="text/javascript" src="js/ajax.js"></script>   
<script>   
function isProcessAjaxUsuario() {   
  
   if(isAjax()){   
      
      document.getElementById("theResponse").innerHTML = objRequest.responseText;   
      
   }   
  
}   
</script>   
</head>   
  
<body>   
<center>   
<html:form action="usuario_valido.do">   
Informe um usuário: <html:text property="nameUser" onkeydown="if(window.event.keyCode == 13){ajaxProcess(this.form, isProcessAjaxUsuario); return false;}" /> <br/>   
<html:button property="button" onclick="ajaxProcess(this.form, isProcessAjaxUsuario)" />   
</html:form>   
<span id="theResponse"></span>   
</center>   
</body>   
</html:html>

Att. Reis

#2