有个问题请大神帮助解决一下？？

Question

<input type="text" name="username" value="${user.username}"/>
改成
<input type="text" name="user.username" value="${user.username}"/>密码一样的道理。改下

Answer 1

大神，我改了，还是空指针，package com.myEdition.action;import java.io.IOException;
import java.sql.SQLException;
import java.util.Map;import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Scope;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.web.servlet.ModelAndView;import com.myEdition.bean.User;
import com.myEdition.dao.UserDAO;
import com.myEdition.dao.impl.UserDAOImpl;
import com.myEdition.domain.Regedit;
import com.myEdition.domain.impl.Regeditlmpl;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;@SuppressWarnings("serial")
@Controller("RegeditAction")@Scope("prototype")
public class RegeditAction extends ActionSupport {

//定义接口Regedit
@Resource

private  User user;
private Regeditlmpl RegeditImpl;

private String username;
private String password;
 
 public String getUsername() {
return username;
} public void setUsername(String username) {
this.username = username;
} public String getPassword() {
return password;
} public void setPassword(String password) {
this.password = password;
}

public User getUser(){
return user;
}

public void setUser(User user){
this.user=user;

}

public void reg(String username,String password){
user.setPassword(password);
user.setUsername(username);

}

/*public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8"); 
HttpSession session = request.getSession(); 
//获取参数名称 

String username = request.getParameter("username"); 
String password = request.getParameter("password"); 

user.setUsername(username);
user.setPassword(password);
session.setAttribute("user", user);
RegeditImpl.saveUser(user);
//return "regedit";
request.getRequestDispatcher("regedit.jsp").forward(request, response);
}*/


public String execute(){
//保存用户提交的信息
User user1 = RegeditImpl.find(this.getPassword(), this.getUsername());
if(user!=null){
Map session=(Map)ActionContext.getContext().getSession();
session.put("user1", user1);
RegeditImpl.saveUser(user);
//User user1 = RegeditImpl.find(user.getPassword(), user.getUsername());

return "regedit";
//返回页面
}
else 
return null;

}
/*
public String regedit(){
System.out.println(user.getUsername());
User user1=new User();
user1.setId(user.getId());
user1.setPassword(user.getPassword());
user1.setUsername(user.getUsername());
regedit.saveUser(user1);
return "regedit";
}*/


public Regeditlmpl getRegeditImpl() {
return RegeditImpl;
} public void setRegeditImpl(Regeditlmpl regeditImpl) {
RegeditImpl = regeditImpl;
}


/*public static void main(String[]args){

ApplicationContext context = new FileSystemXmlApplicationContext("src/applicationContext.xml");
User user2 = new User();
//user2.setId(1);
user2.setPassword("456red");
user2.setUsername("zzqweas");
UserDAO userDao = (UserDAO)context.getBean("UserDAOImpl");
userDao.insert(user2);
}*/
/*public static void main(String[]args){
System.out.println(new RegeditAction().user);
}*/
}
上面是我action代码，你看有错误没？？

Answer 2

两种解决方式：
一种像1L所说；
第二种在action中 implements ModelDriven<User>并覆写
        public User getModel() {
return this.model;
}去掉private  User user;和user的set、get方法

Answer 3

把
//定义接口Regedit
@Resource放到
private Regeditlmpl RegeditImpl;上面如:
 private  User user;
 //定义接口Regedit
 @Resource
 private Regeditlmpl RegeditImpl;前台按1L所说修改！

Answer 4

关键哪是空指针，user=null？
还是find方法里的某句空指针？

Answer 5

我是按楼那样做的，usename和password值可以接收到，但是我调试发现Id为空，数据库我设的id为自动增长，最后报错 RegeditImpl.saveUser(user);为空指针，这是可能是什么原因造成的呢？求大神指点！！

Answer 6

RegeditImpl.saveUser(user);这一句空指针

Answer 7

package com.myEdition.action;import java.io.IOException;
import java.sql.SQLException;
import java.util.Map;import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Scope;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.web.servlet.ModelAndView;import com.myEdition.bean.User;
import com.myEdition.dao.UserDAO;
import com.myEdition.dao.impl.UserDAOImpl;
import com.myEdition.domain.Regedit;
import com.myEdition.domain.impl.Regeditlmpl;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;@SuppressWarnings("serial")
@Controller("RegeditAction")@Scope("prototype")
public class RegeditAction extends ActionSupport {

//定义接口Regedit
@Resource

private  User user;
private Regeditlmpl RegeditImpl;

private String username;
private String password;
 
public void setUsername(String username) {
this.username = username;
}

 public String getUsername() {
return username;
} public void setPassword(String password) {
this.password = password;
}
public String getPassword() {
return password;
}
public User getUser(){
return user;
}

public void setUser(User user){
this.user=user;

}

/*public void reg(String username,String password){
user.setPassword(password);
user.setUsername(username);

}*/

/*public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8"); 
HttpSession session = request.getSession(); 
//获取参数名称 

String username = request.getParameter("username"); 
String password = request.getParameter("password"); 

user.setUsername(username);
user.setPassword(password);
session.setAttribute("user", user);
RegeditImpl.saveUser(user);
//return "regedit";
request.getRequestDispatcher("regedit.jsp").forward(request, response);
}*/


public String execute(){
//保存用户提交的信息

//User user1 = RegeditImpl.find(this.getPassword(), this.getUsername());
if(user!=null){
Map session=(Map)ActionContext.getContext().getSession();
session.put("user1", user);
RegeditImpl.saveUser(user);
//User user1 = RegeditImpl.find(user.getPassword(), user.getUsername());

return "regedit";
//返回页面
}
else 
return "regedit";

}
/*
public String regedit(){
System.out.println(user.getUsername());
User user1=new User();
user1.setId(user.getId());
user1.setPassword(user.getPassword());
user1.setUsername(user.getUsername());
regedit.saveUser(user1);
return "regedit";
}*/


public Regeditlmpl getRegeditImpl() {
return RegeditImpl;
} public void setRegeditImpl(Regeditlmpl regeditImpl) {
RegeditImpl = regeditImpl;
}


/*public static void main(String[]args){

ApplicationContext context = new FileSystemXmlApplicationContext("src/applicationContext.xml");
User user2 = new User();
//user2.setId(1);
user2.setPassword("456red");
user2.setUsername("zzqweas");
UserDAO userDao = (UserDAO)context.getBean("UserDAOImpl");
userDao.insert(user2);
}*/
/*public static void main(String[]args){
System.out.println(new RegeditAction().user);
}*/
}

Answer 8

我是按楼那样做的，usename和password值可以接收到，但是我调试发现Id为空，数据库我设的id为自动增长，最后报错 RegeditImpl.saveUser(user);为空指针，这是可能是什么原因造成的呢？求大神指点！！和id没关系，是因为RegeditImpl这个为null，造成的，你spring相关注解写错了

Answer 9

大神这样做不中啊，就是在保存的时候出现空指针，debug看除了id外username、password都有值，数据库设id为自动增长的，大神觉得是什么问题？？

Answer 10

//定义接口Regedit
 @Resource private  User user;
 private Regeditlmpl RegeditImpl;这个你还是没有改！ 你把@Resource 放到
private Regeditlmpl RegeditImpl; 上面！ 不用注入User对象，应该注入DAO或Manager层！
改成 private  User user;
 @Resource
 private Regedit RegeditImpl; //这里最好用接口，而不用具体实现类！

Answer 11

public class RegeditAction extends ActionSupport {

//定义接口Regedit
private  User user;
@Resource
private Regeditlmpl RegeditImpl;

private String username;
private String password;
 这样吧？这样还是解决不了问题

Answer 12

我是按楼那样做的，usename和password值可以接收到，但是我调试发现Id为空，数据库我设的id为自动增长，最后报错 RegeditImpl.saveUser(user);为空指针，这是可能是什么原因造成的呢？求大神指点！！和id没关系，是因为RegeditImpl这个为null，造成的，你spring相关注解写错了我把几个层的代码给你看看，哪个注解写错了？【controller
】
package com.myEdition.action;import java.io.IOException;
import java.sql.SQLException;
import java.util.Map;import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Scope;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.web.servlet.ModelAndView;import com.myEdition.bean.User;
import com.myEdition.dao.UserDAO;
import com.myEdition.dao.impl.UserDAOImpl;
import com.myEdition.domain.Regedit;
import com.myEdition.domain.impl.Regeditlmpl;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;@SuppressWarnings("serial")
@Controller("RegeditAction")@Scope("prototype")
public class RegeditAction extends ActionSupport {

//定义接口Regedit
private  User user;
@Resource
private Regeditlmpl RegeditImpl;

private String username;
private String password;
 
public void setUsername(String username) {
this.username = username;
}

 public String getUsername() {
return username;
} public void setPassword(String password) {
this.password = password;
}
public String getPassword() {
return password;
}
public User getUser(){
return user;
}

public void setUser(User user){
this.user=user;

}

/*public void reg(String username,String password){
user.setPassword(password);
user.setUsername(username);

}*/

/*public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8"); 
HttpSession session = request.getSession(); 
//获取参数名称 

String username = request.getParameter("username"); 
String password = request.getParameter("password"); 

user.setUsername(username);
user.setPassword(password);
session.setAttribute("user", user);
RegeditImpl.saveUser(user);
//return "regedit";
request.getRequestDispatcher("regedit.jsp").forward(request, response);
}*/


public String execute(){
//保存用户提交的信息

//User user1 = RegeditImpl.find(this.getPassword(), this.getUsername());
if(user!=null){
Map session=(Map)ActionContext.getContext().getSession();
session.put("user1", user);
RegeditImpl.saveUser(user);
//User user1 = RegeditImpl.find(user.getPassword(), user.getUsername());

return "regedit";
//返回页面
}
else 
return "regedit";

}
/*
public String regedit(){
System.out.println(user.getUsername());
User user1=new User();
user1.setId(user.getId());
user1.setPassword(user.getPassword());
user1.setUsername(user.getUsername());
regedit.saveUser(user1);
return "regedit";
}*/


public Regeditlmpl getRegeditImpl() {
return RegeditImpl;
} public void setRegeditImpl(Regeditlmpl regeditImpl) {
RegeditImpl = regeditImpl;
}


/*public static void main(String[]args){

ApplicationContext context = new FileSystemXmlApplicationContext("src/applicationContext.xml");
User user2 = new User();
//user2.setId(1);
user2.setPassword("456red");
user2.setUsername("zzqweas");
UserDAO userDao = (UserDAO)context.getBean("UserDAOImpl");
userDao.insert(user2);
}*/
/*public static void main(String[]args){
System.out.println(new RegeditAction().user);
}*/
}【service】package com.myEdition.domain.impl;import javax.annotation.Resource;import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.myEdition.bean.User;
import com.myEdition.dao.UserDAO;
import com.myEdition.dao.impl.UserDAOImpl;
import com.myEdition.domain.Regedit;@Transactional
@Service
public class Regeditlmpl  implements Regedit{
private String msg;
@Resource
private UserDAOImpl UserDAOImpl;



public UserDAOImpl getUserDAOImpl() {
return UserDAOImpl;
}
public void setUserDAOImpl(UserDAOImpl userDAOImpl) {
UserDAOImpl = userDAOImpl;
}
public void setMsg(String msg) {
this.msg = msg;
}
//删除用户
public void deleteUser(User user) {
UserDAOImpl.delete(user);
}
//获取是否保存成功信息
public String getMsg() {

return msg;
}
//保存用户
public void saveUser(User user) {
UserDAOImpl.insert(user);
msg="注册成功！";

}
//修改用户
public void updateUser(User user) {
UserDAOImpl.update(user);

}

//查询用户

public User find(String username,String password){
return UserDAOImpl.find(username, password);
}
public void insert(User user) {
// TODO Auto-generated method stub

}




}【DAO】package com.myEdition.dao.impl;
import java.util.List;
import javax.annotation.Resource;import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
import org.springframework.stereotype.Repository;
import com.resource.AppContext;
import com.myEdition.bean.User;
import com.myEdition.dao.UserDAO;
@Repositorypublic class UserDAOImpl extends HibernateDaoSupport implements UserDAO{
//@Resource
//private SessionFactory sessionFactory;
/*private Session getSession(){
return sessionFactory.getCurrentSession();
}*/
/*public Session getSession(){
return sessionFactory.getCurrentSession();
}

private static UserDAO UserDAO;
public UserDAOImpl() {
super();
}

public static UserDAO  getInstance(){
if(UserDAO==null){
UserDAO=(UserDAO)AppContext.getInstance().getAppContext().getBean("UserDAO"); 
}
return UserDAO;
}*/

/*public void setSessionFactory(SessionFactory sessionFactory){
this.sessionFactory=sessionFactory;
}*/

//Session session=sessionFactory.openSession();

private String hql="from User u where u.username = ?";
//删除用户
public void delete(User user) {
getHibernateTemplate().delete(user);

}
//新增用户
public void insert(User user) {
getHibernateTemplate().save(user);

}
//查询用户
public User find(String username,String password) {
/*User user = null;
List users = getSession().createQuery(hql).setParameter(0, name).list();
if(users.size()!=0){
user=(User)users.get(0);
}*/
String str[]={username,password};
List list = getHibernateTemplate().find("from user where username=? and password=?",str);
if(list.size()>0)
return (User)list.get(0);
else return null;

//return user;
}
//修改用户
public void update(User user) {

getHibernateTemplate().update(user);

}
public List query(String name) {
// TODO Auto-generated method stub
return null;
}

//注入sevice





}

Answer 13

private Regeditlmpl RegeditImpl; 红色部分不要直接用具体实现类，应该使用接口！ 
再不行你把@Resource 改成@Autowired 试试！

Answer 14

@Controller("RegeditAction")@Scope("prototype")
public class RegeditAction extends ActionSupport {

//定义接口Regedit
private  User user;
@Autowired
private Regedit Regedit;

已改过，无济于事

Answer 15

我把配置发给你们看看<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"

xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/aop  http://www.springframework.org/schema/aop/spring-p-3.0.xsd

">


<!--  启用自动扫描
<context:component-scan base-package="com.myEdition"></context:component-scan> -->
<!-- 事务管理  -->
<!-- 以下的被注释
<tx:annotation-driven transaction-manager="transactionManger"/>
<bean id="transactionManger" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
 -->
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName"
value="com.mysql.jdbc.Driver">
</property>
<property name="url"
value="jdbc:mysql://localhost:3306/myedition">
</property>
<property name="username" value="root"></property>
<property name="password" value="root"></property>
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource"></ref>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</prop>
 <prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
<property name="mappingResources">
<list>
   <value>com/myEdition/bean/Content.hbm.xml</value>
  <value>com/myEdition/bean/ContentType.hbm.xml</value>  
  <value>com/myEdition/bean/User.hbm.xml</value>  
</list>
</property>

</bean>


 
 
 <bean id="transactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean><!-- 配置事务拦截器 -->
<bean id="transactionInterceptor"  class="org.springframework.transaction.interceptor.TransactionInterceptor">
<!--事务拦截器BEAN需要依赖注入一个事物管理器 -->
<property name="transactionManager" ref="transactionManager"/>
<property name="transactionAttributes">
<!-- 定义事物传播属性 -->
<props>
<prop key="delete*"> PROPAGATION_REQUIRED</prop>
<prop key="insert*"> PROPAGATION_REQUIRED</prop>
<prop key="update*"> PROPAGATION_REQUIRED</prop>
<prop key="save*"> PROPAGATION_REQUIRED</prop>
<prop key="find*"> PROPAGATION_REQUIRED</prop>
<prop key="get*"> PROPAGATION_REQUIRED</prop>
<prop key="*"> PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean><!-- 定义BeanNameAutoProxyCreator,该bean是个bean后处理器，无需被引用，因此没有id属性这个bean后处理器，根据事务拦截器为目标bean自动创建事务代理--><bean id="userDAOProxy" class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<!-- 指定哪些bean自动生成业务代理 --><property name="beanNames">
<!--   下面是所有需要自动创建事务代理的bean-->
<list>
<value>RegeditImpl</value>
<value></value>
<value></value>
</list>
</property>
<!--   下面定义BeanNameAutoProxyCreator所需的事务拦截器-->
<property name="interceptorNames">
<list>
<value>transactionInterceptor</value></list>
</property>
</bean> <!--spring beanName dao层的beanName -->
   <bean id="UserDAOImpl" class="com.myEdition.dao.impl.UserDAOImpl">
  <property name="sessionFactory" ref="sessionFactory"></property>
 </bean>  <bean id="ContentTypeDAOImpl" class="com.myEdition.dao.impl.ContentTypeDAOImpl">
  <property name="sessionFactory" ref="sessionFactory"></property>
 </bean>
 
 <bean id="ContentDAOImpl" class="com.myEdition.dao.impl.ContentDAOImpl">
 <property name="sessionFactory" ref="sessionFactory"></property>
 </bean>
 <!-- spring容器管理业务逻辑层service -->
  <bean id="RegeditImpl" class="com.myEdition.domain.impl.Regeditlmpl">
 <property name="UserDAOImpl" ref="UserDAOImpl"></property>
 </bean>
 
 <bean id="SetContentTypeImpl" class="com.myEdition.domain.impl.SetContentTypeImpl">
 <property name="ContentTypeDAOImpl" ref="ContentTypeDAOImpl"></property>
 </bean>
 <bean id="EditImpl" class="com.myEdition.domain.impl.EditImpl">
 <property name="ContentDAOImpl" ref="ContentDAOImpl"></property>
 </bean>
  <!-- spring容器管理action 
 <bean id="RegeditAction" class="com.myEdition.action.RegeditAction">
 <property name="RegeditImpl" ref="RegeditImpl"></property>
 </bean>
 <bean id="ContentTypeAction" class="com.myEdition.action.ContentTypeDAOImpl">
 <property name="SetContentTypeImpl" ref="SetContentTypeImpl"></property>
 </bean>
 -->
</beans>

Answer 16

你是想用注解bean还是手动注入bean！
如果注解把
<context:component-scan base-package="com.myEdition"></context:component-scan> 
不要注释！
把下面的那些
<bean id="UserDAOImpl" class="com.myEdition.dao.impl.UserDAOImpl">
这些类全部给注释掉！！！！在Regeditimpl中的saveUser()方法中加一个断点，看能进去不！ 

Answer 17

建议看下spring注解注入！
http://lvqionghua.blog.163.com/blog/static/185277420116113816675/