SSH2整合中老是出现 java.lang.NullPointerException ，DAO未注入

SSH2整合中老是出现 java.lang.NullPointerException ，DAO未注入的情况，我查不少资料但还是没能解决，望各位大侠帮帮忙
 POJO文件
package org.lxh.ssh2.pojo;
public class News implements java.io.Serializable {
private Integer nid;
private String title;
private String content;
public News() {
}
public News(String title, String content) {
this.title = title;
this.content = content;
}
public Integer getNid() {
return this.nid;
}

public void setNid(Integer nid) {
this.nid = nid;
}

public String getTitle() {
return this.title;
}

public void setTitle(String title) {
this.title = title;
}

public String getContent() {
return this.content;
}

public void setContent(String content) {
this.content = content;
}

}
DAO接口
package org.lxh.ssh2.dao;
import java.util.List;
import org.lxh.ssh2.pojo.News;
public inte易做图ce INewsDAO {
    public void doCreate(News news) throws Exception;
    public void doRemove(News news) throws Exception;
    public void doUpdate(News news) throws Exception;
    public List<News> findAll() throws Exception;
    public News findById(Integer id) throws Exception;

}
DAO实现
package org.lxh.ssh2.dao.impl;
import java.util.List;
import org.lxh.ssh2.dao.INewsDAO;
import org.lxh.ssh2.pojo.News;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

public class NewsDAOImpl extends HibernateDaoSupport implements INewsDAO {

public void doCreate(News news) throws Exception {
super.getHibernateTemplate().save(news);
}

public void doRemove(News news) throws Exception {
super.getHibernateTemplate().delete(news);

}

public void doUpdate(News news) throws Exception {
super.getHibernateTemplate().update(news);

}

@SuppressWarnings("unchecked")
public List<News> findAll() throws Exception {
String hql="from News news";
return (List<News>)super.getHibernateTemplate().find(hql);
}

public News findById(Integer id) throws Exception {
News news=(News)super.getHibernateTemplate().get(News.class, id);
return news;
}

}
action实现（只做了一个表查询的操作）
package org.lxh.ssh2.action;

import java.util.List;

import org.lxh.ssh2.dao.INewsDAO;
import org.lxh.ssh2.pojo.News;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

@SuppressWarnings("serial")
public class NewsAction extends ActionSupport{
    private News news=null;
    private INewsDAO dao=null;
    public String findAll() throws Exception{
     List<News> n=this.dao.findAll();
     ActionContext.getContext().getSession().put("news",n);
     return SUCCESS;
    }
public News getNews() {
return news;
}
public void setNews(News news) {
this.news = news;
}
public void setDao(INewsDAO dao) {
this.dao = dao;
}
 
}
下面是我的配置文件
applicationContext-dataSource.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">


<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName"
value="com.microsoft.sqlserver.jdbc.SQLServerDriver">
</property>
<property name="url"
value="jdbc:sqlserver://localhost:1433;databaseName=mldn">
</property>
<property name="username" value="sa"></property>
<property name="password" value="123"></property>
</bean>

</beans>

applicationContext-dao.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">
      <bean id="inewsdao" class="org.lxh.ssh2.dao.INewsDAO" abstract="true"/>
     <bean id="newsdaoimpl" class="org.lxh.ssh2.dao.impl.NewsDAOImpl" parent="inewsdao">
       <property name="hibernateTemplate">
         <ref bean="hibernateTemplate"/>
       </property>
     </bean>
</beans>

applicationContext-struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

    <bean id="newsAction" class="org.lxh.ssh2.action.NewsAction">
       <property name="dao">
          <ref bean="newsdaoimpl"/>
       </property>
    </bean>
</beans>

struts.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

    <package name="news" namespace="/" extends="struts-default">
       <action name="news_*" class="org.lxh.ssh2.action.NewsAction" method="{1}">
         <result name="SUCCESS" type="dispatcher">news.jsp</result>
       </action>
    </package>

</struts>

web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
   <context-param>
     <param-name>contextConfigLocation</param-name>
     <param-value>/WEB-INF/classes/applicationContext-*.xml</param-value>
   </context-param>
   <listener>
     <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>
   <filter>
       <filter-name>struts2</filter-name>
       <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
   </filter>
   <filter-mapping>
      <filter-name>struts2</filter-name>
      <url-pattern>/*</url-pattern>
   </filter-mapping>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

希望各位指教，谢谢！ --------------------编程问答-------------------- <bean id="inewsdao" class="org.lxh.ssh2.dao.INewsDAO" abstract="true"/>
把id换一下，试一下！，别和类名一样！ --------------------编程问答-------------------- 谢谢热情回答，还是不行 --------------------编程问答-------------------- spring分层体系是这样的。。。applicationContext.xml文件里最底层是  dataSource， 然后是sessionFactory。。。然后是 DAOImpl  然后是ServiceImpl (一般service后面还有声明式事务管理) 最后才是注入 action。。。这样是层层的依赖注入的。。。楼主你都没有为这个dataSource配置 sessionFactory。。。。这可能是你报异常的原因 --------------------编程问答-------------------- 不好意思！！有的，忘粘贴了
applicationContext-hibernate.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.SQLServerDialect
</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>org/lxh/ssh2/pojo/News.hbm.xml</value></list>
</property>
</bean>
<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
   <property name="sessionFactory">
     <ref bean="sessionFactory"/>
   </property>
</bean>
</beans> --------------------编程问答--------------------

引用 1 楼  的回复:

<bean id="inewsdao" class="org.lxh.ssh2.dao.INewsDAO" abstract="true"/>
把id换一下，试一下！，别和类名一样！

朋友你好！根据你说的改了后是找不到Action了错误如下：

exception 

Unable to instantiate Action, org.lxh.ssh2.action.NewsAction,  defined for 'news_findAll' in namespace '/'Failed to convert property value of type [org.lxh.ssh2.action.NewsAction] to required type [org.lxh.ssh2.pojo.News] for property 'news'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [org.lxh.ssh2.action.NewsAction] to required type [org.lxh.ssh2.pojo.News] for property 'news': no matching editors or conversion strategy found
com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:307)
com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:388)
com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:187)
org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:478)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)


root cause 

org.springframework.beans.TypeMismatchException: Failed to convert property value of type [org.lxh.ssh2.action.NewsAction] to required type [org.lxh.ssh2.pojo.News] for property 'news'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [org.lxh.ssh2.action.NewsAction] to required type [org.lxh.ssh2.pojo.News] for property 'news': no matching editors or conversion strategy found
org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:385)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1106)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:862)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:274)
com.opensymphony.xwork2.spring.SpringObjectFactory.autoWireBean(SpringObjectFactory.java:182)
com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:162)
com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:133)
com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:139)
com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:109)
com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:288)
com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:388)
com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:187)
org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:478)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)


root cause 

java.lang.IllegalArgumentException: Cannot convert value of type [org.lxh.ssh2.action.NewsAction] to required type [org.lxh.ssh2.pojo.News] for property 'news': no matching editors or conversion strategy found
org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:231)
org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:138)
org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:380)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1106)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:862)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:274)
com.opensymphony.xwork2.spring.SpringObjectFactory.autoWireBean(SpringObjectFactory.java:182)
com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:162)
com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:133)
com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:139)
com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:109)
com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:288)
com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:388)
com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:187)
org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:478)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)

补充：Java ,  Web 开发