ext_struts报错 Could not find action or result

代码如下 action
String str = "SUCCESS";
public String login() throws Exception {
TbWorker t=workerService.workerCheck(worker);
if(t==null){
str="error";
System.out.println("error");
}
return str;
}<script type="text/javascript">
Ext.onReady(function(){
Ext.QuickTips.init();
var loginForm = new Ext.form.FormPanel({
height:120,
width:220,
title:'登陆',
frame:true,
bodyStyle:'padding:5 5 5 5',
url:'',
renderTo:'form',
defaultType:'textfield',
defaults:{
labelSeparator:': ',//分隔符
labelWidth:50,//标签宽度
width:150,//字段宽度
allowBlank:false,//是否允许为空
labelAlign:'left',//标签对齐方式
msgTarget:'side'//在字段最右边显示一个提示信息
},
items:[{
fieldLabel:'用户名',
name:'userName',
selectOnFocus:true,//得到焦点是自动选择文本
regex: /^[a-zA-Z]{1}([a-zA-Z0-9]|[._]){4,19}$/,
regexText: '只能输入5-20个以字母开头、可带数字、"_"、"."的字串' //验证错误之后的提示信息
},{
fieldLabel:'密码',
inputType:'password',//设置输入类型为password
name:'password'

}
],
buttons:[{
text:'登陆',
handler:function(){

loginForm.getForm().submit({
clientValidation:true,//进行客户端验证
url:'worker_login.action?method=login',//请求的地址
method:'get',//请求方式
success:function(form,action){
var jsonobject = Ext.util.JSON.decode(action.response.responseText);   //将返回的JSON数据转换成JSON对象,转换失败即报错.
Ext.Msg.alert(success);//要跳转到管理页面
//Ext.Msg.alert("msg,oject",jsonobject.msg); 
},
failure:function(form,action){
Ext.Msg.alert('提示','系统登陆失败，原因：'+action.failureType);
}
});
}
},{
text:'重置',
handler:function(){
loginForm.form.reset();
}
}
]
});
});
</script>xml:web<?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-jar.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<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> <welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
xml:struts.xml<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC 
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts> <package name="worker" extends="json-default" namespace="/">
<action name="worker_login" class="WorkerAction">
<result type="json"></result>
</action>
</package>
</struts>