Erro exception no action ao cadastrar

[ju1]

Olá, queria saber o motivo desse erro ao cadastra os meu
dados?
O action cadastra todos os campos mas não
vai para página sucesso.jsp.

Segue o erro :

message

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

exception

javax.servlet.ServletException
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:545)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:486)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

java.lang.NullPointerException
cadastro.action.SaveInsertUsuarioAction.execute(SaveInsertUsuarioAction.java:121)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.

Segue meu action :

package cadastro.action;

import java.sql.SQLException;
import java.util.LinkedList;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.validator.DynaValidatorForm;

import cadastro.bean.AdminUsers;
import cadastro.bean.UserData;

public class SaveInsertUsuarioAction extends Action {

public ActionForward execute(
	ActionMapping mapping,
	ActionForm form,
	HttpServletRequest request,
	HttpServletResponse response)
	throws Exception {
		
   DynaValidatorForm dynaForm = (DynaValidatorForm) form;
	ActionErrors errors = new ActionErrors();
	String senha1 = (String)dynaForm.get("senha");
	String senha2 = (String)dynaForm.get("confirmasenha");
	
	String nome = (String)dynaForm.get("nome");
	String sobrenome = (String)dynaForm.get("sobrenome");
	String email = (String)dynaForm.get("email");
	String login = (String)dynaForm.get("login");
	String senha = (String)dynaForm.get("senha");


   
     if (senha1.equals(senha2)) {
          
        try {
        
         HttpSession session = request.getSession(true);
			
			// popula o bean do usuario com os dados que vieram do Form
			 UserData user = (UserData) session.getAttribute("insertUserBean");

        user.setNome((String)dynaForm.get("nome"));
			user.setSobrenome((String)dynaForm.get("sobrenome"));
			user.setOpcaoemail((String)dynaForm.get("opcaoemail"));
			user.setEmail((String)dynaForm.get("email"));
			user.setTelefone((String)dynaForm.get("telefone"));					
			user.setEndereco((String)dynaForm.get("endereco"));
			user.setBairro((String)dynaForm.get("bairro"));
			user.setCidade((String)dynaForm.get("cidade"));
			user.setEstado((String)dynaForm.get("estado"));
			user.setLogin((String)dynaForm.get("login"));
			user.setSenha((String)dynaForm.get("senha"));
        user.setInformativos((String)dynaForm.get("informativos"));						
			
		  		//user.setSenha(senha1);
											
		
		
	      AdminUsers adminUsers = new AdminUsers();
			
			adminUsers.insertUser(user);
			
			LinkedList userList = (LinkedList) session.getAttribute("userListBean");
			userList.add(user);
			session.removeAttribute("insertUserBean");
	
          }
           catch(SQLException e1) 
           {
      
        
         if (e1.getErrorCode() == 1062) {
               errors.add(
					ActionErrors.GLOBAL_ERROR,
					new ActionError("error.Email.duplicateKey"));
			    
              }
       }
              
			      
	   }else {
		errors.add(
			ActionErrors.GLOBAL_ERROR,
			new ActionError("error.confirmasenha"));
	}


 
 if (!errors.isEmpty()) {
		   saveErrors(request, errors);
		   return (mapping.findForward("error"));
      }else{
	     return (mapping.findForward("success"));
	   }
} 

}

[julianostr]

Está dando o erro

java.lang.NullPointerException cadastro.action.SaveInsertUsuarioAction.execute(SaveInsertUsuarioAction.java:121)

na linha 121 da classe SaveInsertUsuarioAction.

Veja o que tem nessa linha e verifique se algum objeto não foi instanciado ou algum atributo está nulo.