高端大气上档次BUG-->Action 里 Service 偶现空指针错误

 

java.lang.NullPointerException
    at com.sunwave.action.privilege.UserAction.findUserPageInfo(UserAction.java:78)

省略N字

框架：SSH，service在Action中注入，配置文件如下：

<!--用户管理-->
    <bean id="userAction" class="com.sunwave.action.privilege.UserAction" scope="prototype">
        <property name="userService" ref="userService"/>      
        <property name="systemParameterService" ref="systemParameterService"></property>        
    </bean>   
    <bean id="userService" class="com.sunwave.service.impl.privilege.UserServiceImpl"
        parent="baseService">
        <property name="roleService" ref="roleService"/>
        <property name="empService" ref="empService"/>
        <property name="systemParameterService" ref="systemParameterService"/>
        <property name="userDao"><ref bean="userDao"/></property>     
    </bean>    
    <bean id="userDao" class="com.sunwave.dao.impl.privilege.UserDaoHibImpl" 
          parent="baseDAO">
    </bean>

 

一般情况下，不会出现该错误，系统发布到公网后偶现，初步怀疑是高访问量的并发性错误，怀疑是否和service的单例模式有关，求解~~