I am insert data in mysql through struts hibernate integration. But above error is coming. Please help me I am sending our Insert Class coding

My Insert class coding

package com.myapp.struts;

import java.sql.SQLException;

import org.hibernate.SQLQuery;
import javax.servlet.ServletContext;
import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
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.action.ActionMessage;
/**
 *
 * @author pradeep.kundu
 */
public class InsertDataAction extends Action {


    private static final String SUCCESS = "success";
    private static final String FAILURE = "failure";

    boolean flag;
    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
          ActionErrors errors = new ActionErrors();
          InsertDataForm idf = new InsertDataForm();
          Integer userId = idf.getuserId();
          String firstName = idf.getfirstName();
          String lastName = idf.getlastName();
          Integer age = idf.getage();
          Long number = idf.getnumber();
           Session session = null;
           System.out.println("Getting session factory");
 /*Get the servlet context */
         ServletContext context =
         request.getSession().getServletContext();
         try {
            Configuration cfg = new Configuration();
             cfg.configure("hibernate.cfg.xml");
 /*Retrieve Session Factory */
       SessionFactory _factory = new
          Configuration().configure().buildSessionFactory();
 /*Open Hibernate Session */
         session = _factory.openSession();
         Transaction tx = session.beginTransaction();
         String str = "insert into emp values(?,?,?,?,?)";
         SQLQuery query = session.createSQLQuery(str);
         System.out.println("Pradeep");
        if(userId!=null){
          query.setInteger(1,userId);
          System.out.println("pra"); 
          query.setString(2,firstName);
          System.out.println("pra");
          query.setString(3,lastName);
          System.out.println("pra");
          query.setInteger(4,age);
          System.out.println("pra");
          query.setLong(5,number);
          System.out.println("pra");
        }
          int row = query.executeUpdate();
          //session.saveOrUpdate(query);
          System.out.println("data is successfully submitted"); 
          tx.commit();
          session.close();
       }
       catch (Exception ex) {
            errors.add("SQLException", new ActionMessage("error.SQLException"));
            throw new SQLException(ex.fillInStackTrace());
        }
           saveErrors(request, errors);
           if (errors.isEmpty()) {
            flag = true;
        } else {
            flag = false;
          }
        if (flag == true ) {
            return mapping.findForward(SUCCESS);
        } else {
            return mapping.findForward(FAILURE);
        }
   }
}

Thanks in advance
Pradeep Kundu