求大神解决CAS与spring Security2.0问题

Question

最近一直在研究CAS整合spring Security2.0，遇到了不少问题，网上的关于2.0的帖子实在太少了
我配置了applicationContext-springSecurity.xml文件，但是登录完CAS后，出现了页面重定向循环，求大神帮忙指点指点，我的xml是：

<?xml version="1.0" encoding="UTF-8"?>
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/security
http://www.springframework.org/schema/security/spring-security-2.0.4.xsd">

<beans:bean id="casEntryPoint"  
    class="org.springframework.security.ui.cas.CasProcessingFilterEntryPoint">  
    <beans:property name="loginUrl"  
        value="http://vest.cn:8080/cas/login" />  
    <beans:property name="serviceProperties"  
        ref="serviceProperties" />  
</beans:bean>   

<beans:bean id="serviceProperties"  
    class="org.springframework.security.ui.cas.ServiceProperties">  
    <beans:property name="service"  
        value="http://vest.cn:8080/xxx/login" />  
    <beans:property name="sendRenew" value="false" />  
</beans:bean> 

<beans:bean id="casProcessingFilter"

class="org.springframework.security.ui.cas.CasProcessingFilter">



/beans:bean
class="org.springframework.security.providers.cas.CasAuthenticationProvider">





value="http://vest.cn:8080/cas" />
/beans:bean
/beans:property

/beans:bean

  <beans:bean id="userDetailsService "

class="com.xxx.rmplatform.security.userdetails.impl.UserDetailsHibernateImpl">


/beans:bean
class="com.xxx.rmplatform.components.security.userdetails.impl.ExpandPasswordEncoder" />