Unable to instantiate Action, userAction, defined for 'userAction' in namespace

Question

错误如下：
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception Unable to instantiate Action, userAction,  defined for 'userAction' in namespace '/'userAction
com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:306)
com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:387)
com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:186)
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.ClassNotFoundException: userAction
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
com.opensymphony.xwork2.util.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:146)
com.opensymphony.xwork2.ObjectFactory.getClassInstance(ObjectFactory.java:96)
com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:206)
com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:128)
com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:139)
com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:109)
com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:287)
com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:387)
com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:186)
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)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.20 logs.
bean.xml：<bean id="userAction" class="com.action.UserAction" scope="prototype">
<property name="userService" ref="userService"/>
</bean>
struts。xml：<package name="default" extends="struts-default" namespace="/">
<action name="userAction" class="userAction">
   <result name="login">home.jsp</result>
   <result name="addUser">index.jsp</result>
   
</action>

</package>userAction://登录
public String login() throws Exception{
try{
User u = this.userService.login(login_name, login_password);
if(u != null){
ActionContext.getContext().getSession().put("USERS", u);
return "login";
}else{
System.out.println("错误");
return "fail";
}
}catch(Exception e){
e.printStackTrace();
return "error";
}

}在线等 帮帮忙~

Answer 1

好吧，我也遇到了。刚好解决了
Unable to instantiate Action, action.RegistAction,  defined for 'regist' in namespace '/'nullroot cause 
java.lang.NullPointerException
action.RegistAction.<init>(RegistAction.java:14)
主要原因是root cause下空指针异常 。的确在RegistAction中user还没有new使用了。
楼主的是java.lang.ClassNotFoundException: userAction 在struts.xml配置中：
<action name="userAction" class="userAction">弄错了
应该是class="com.action.UserAction"
希望对楼下的有帮助

Answer 2

其实楼主使用的是spring来初始化userAction，在struts.xml里面那么写是对的。
应该是spring哪里配置错了，导致spring annotation没有初始化userAction。
我也遇到类似的问题，Log和楼主一样，但是没有找到哪错了，楼主可解决了？希望提供下思路。灰常感谢。

Answer 3

strust.xml:
<struts>
<package name="kely" namespace="/" extends="struts-default">
<action name="user_*" class="loginAction" method="{1}">
<result name="login">/login.jsp</result>
</action>
</package>
</struts>    spring配置：
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
     http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
     http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
     http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-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-aop-3.0.xsd">
     
<!-- 注解扫描 -->
<context:component-scan base-package="com.kely" />
<context:annotation-config />

</beans>web.xml：
<?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>classpath:applicationContext-*.xml</param-value>
</context-param>
 
  <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>*.action</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>
  </web-app>报楼主的错误？不知为什么？解决中……望提供参考