struts2.5运行报错，求助谢谢！！！

struts.xml配置如下。但是当我访问
http://localhost:8080/Struts2_0900_CharacterEncoding/user/userAction!add&name=a
的时候报错：•There is no Action mapped for namespace [/user] and action name [index] associated with context path [/Struts2_0900_CharacterEncoding
]
我不明白它为什么要找name=index的action

 <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
    "http://struts.apache.org/dtds/struts-2.5.dtd">

<struts>

    <constant name="struts.devMode" value="true" />
    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <constant name="struts.il8n.encoding" value="UTF-8"></constant>

    <package name="user" namespace="/user" extends="struts-default" >
        <action name="userAction" class="com.gold.struts2.action.UserAction" >
            <result name="error">/userError_success.jsp</result>
            <result>/userAdd_success.jsp</result>
            <allowed-methods>add</allowed-methods>
        </action>

    </package>
</struts>

我只知道url显示传参数的形式是url?name="sd"&age=20，没见过！用来传参的。然后你要看你的相对路径写对了没，对照着action的绝对路径看下。