请教达人，使用comet遇到问题

Question

一直出现这个错误。已经将cometd-api-0.9.20080221.jar、cometd-bayeux-6.1.10.jar、jetty-util-6.1.10.jar放到lib下了。
我的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">
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<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>/*</url-pattern>
</filter-mapping>
<!--配置服务器推送的支持类-->
<servlet>
<servlet-name>cometd</servlet-name>
<servlet-class>org.mortbay.cometd.continuation.ContinuationCometdServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>cometd</servlet-name>
<url-pattern>/cometd/*</url-pattern>
</servlet-mapping></web-app>
我的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="klan" extends="struts-default" >
<action name="LoginAction" class="klan.action.LoginAction" >
<result name="success">/main.jsp</result>
<result name="error">/index.jsp</result>
</action>
<action name="LogOutAction" class="klan.action.LoginAction" method="logOut">
<result name="success">/index.jsp</result>
<result name="error">/main.jsp</result>
</action>
</package>
</struts>    
web
<script type="text/javascript">
    dojo.require("dojox.cometd");
    //连接comet服务
    r=dojox.cometd.init("cometd");
      //注册信道
    dojox.cometd.subscribe("/Alarm",currentProcessor,"processHQ");
 </script>