[]struts2整合spring,无法注入service

<bean id="UserInfoDAO" class="test.dao.impl.UserInfoDAO" scope="prototype">        <property name="sessionFactory">            <ref bean="sessionFactory" />        </property>    </bean>    <!-- 业务逻辑层注入 -->    <bean id="UserInfoService" class="test.service.impl.UserInfoService" scope="prototype">        <property name="userInfoDAO" ref="UserInfoDAO" />    </bean>    <!-- Action注入 -->    <bean id="userAction" class="test.action.UserInfoAction" scope="prototype">        <property name="userService" ref="UserInfoService"/>    </bean>

<struts>    <constant name="struts.objectFactory" value="spring" />    <constant name="struts.devMode" value="false" />    <include file="example.xml"/>    <package name="default" namespace="/" extends="struts-default">        <action name="userAction" class="userAction">            <result name="success">/showAll.jsp</result>        </action>    </package>        <!-- Add packages here --></struts>

<!-- 加载时加载所有spring配置文件 -->    <context-param>        <param-name>contextConfigLocation</param-name>        <param-value>/WEB-INF/applicationContext.xml</param-value>    </context-param>        <!-- 拦截器 拦截客户所有请求 -->    <filter>        <filter-name>struts2</filter-name>        <filter-class>            org.apache.struts2.dispatcher.FilterDispatcher        </filter-class>    </filter>        <filter-mapping>        <filter-name>struts2</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>        <listener>           <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>       </listener>       <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list>

 public class UserInfoAction extends ActionSupport{    private UserInfoService userService;    private UserInfo user;    @Override    public String execute() throws Exception    {        if(userService.getUserInfoByName(user))        {            System.out.println("成功");            return SUCCESS;        }        return null;    }    public UserInfo getUserInfo()    {        return user;    }    public void setUserInfo(UserInfo user)    {        this.user = user;    }    public void setUserService(UserInfoService userService)    {        this.userService = userService;    }}