蛋疼的j2ee空指针异常

 

最近完成一个j2ee的网站项目，  遇到了下面这个问题

 

写一个登录类，保存登录用户的session 用户， 密码

 

package com.tyland.action;



import java.sql.Array;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;



import org.hibernate.Query;

import org.hibernate.SessionFactory;

import org.hibernate.classic.Session;

import com.opensymphony.xwork2.ActionSupport;

import com.tyland.domain.AccountType;

import com.tyland.dao.AccountTypeDao;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;





public class LoginAction extends ActionSupport

{

     /**

     *   gdcc  登陆页面逻辑

     */

    

    

    private static final long serialVersionUID = 1059318446535409471L;

    private String password;

    private SessionFactory  sessionFactory;

    private String username;

    private Map<String, Object> session;

    private AccountType  loginUser;

    private AccountTypeDao   accountTypeDao;

    

    public AccountType getLoginUser() {

        return loginUser;

    }



    public void setLoginUser(AccountType loginUser) {

        this.loginUser = loginUser;

    }



    public Map<String, Object> getSession() {

        return session;

    }



    public void setSession(Map<String, Object> session) {

        this.session = session;

    }



    public SessionFactory getSessionFactory() {

            return sessionFactory;

            }

     

     public void setSessionFactory(SessionFactory sessionFactory) {

            this.sessionFactory = sessionFactory;

            }

        

     public String getPassword() {

        return password;

    }

    public void setPassword(String password) {

        this.password = password;

    }

    public String getUsername() {

        return username;

    }

    public void setUsername(String username) {

        this.username = username;

    }



     public String execute() throws Exception

     {     

         return "loginsucess";          

         

     }

public String  login ()throws Exception

 {

     /**

      * 

      *   不使用spring框架来进行登陆页面的注册

      */

     Session session1 =  sessionFactory.openSession();

     

     String hql = "from AccountType u where u.username=? and u.password=?";

     Query query = session1.createQuery(hql);

     query.setParameter(0, username);

     query.setParameter(1, password);

     System.out.println(username);

     System.out.println(password);

     List   user = query.list();

     

//     loginUser.setUsername("1221")；                                          

//    loginUser.setId(11111);

//     loginUser.setPassword("sdadsadas");

//调这个函数出现空指针异常

     

     this.loginUser =  this.accountTypeDao.startlogin(username, password);

         

     this.session.put("sessionUser", this.loginUser);

     if(user.size()>0)

     {  

        

         session1.close();

         return "loginsucess";  

     }

     else

     {

      return "logout";

     }

 }



}

 

 注释部分的空指针异常，非常奇怪！纠结！！！！