在ssh2框架下，忽然整個userAction下的action都不可用了。之前的修改是在userAction的login方法里設置登錄成功則將user對象插入httpSession；在報錯后撤銷修改，但是仍然不行。報錯信息如下：exception Unable to instantiate Action, list, defined for 'listUser' in namespace '/'Error creating bean with name 'list' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [cn.camp.action.UserAction]: Constructor threw exception; nested exception is java.lang.NullPointerExceptionroot cause org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'list' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [cn.camp.action.UserAction]: Constructor threw exception; nested exception is java.lang.NullPointerExceptionorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:451)org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:270)org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)root cause org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [cn.camp.action.UserAction]: Constructor threw exception; nested exception is java.lang.NullPointerException在網上搜了一下相關內容，都沒有這種情況?，F在是其他的action都可用，就是userAction下的所有方法都不行了，不知道為什么