AuthenticationCredentialsNotFoundException怎么解决？

Question

严重: Servlet.service() for servlet jsp threw exception
org.acegisecurity.AuthenticationCredentialsNotFoundException: An Authentication object was not found in the SecurityContext
at org.acegisecurity.intercept.AbstractSecurityInterceptor.credentialsNotFound(AbstractSecurityInterceptor.java:414)
at org.acegisecurity.intercept.AbstractSecurityInterceptor.beforeInvocation(AbstractSecurityInterceptor.java:308)
at org.acegisecurity.intercept.web.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:113)
at org.acegisecurity.intercept.web.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:79)
at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303)
at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:207)
at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:220)
at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303)
at org.acegisecurity.util.FilterChainProxy.doFilter(FilterChainProxy.java:173)
at org.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:120)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)在spring中用acegi，访问受保护的页面时候，出现以上异常，怎么回事？
spring配置文件：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="httpSessionContextIntegrationFilter" class="org.acegisecurity.context.HttpSessionContextIntegrationFilter">
</bean>
<bean id="authenticationProvider" class="org.acegisecurity.providers.dao.DaoAuthenticationProvider">
<property name="userDetailsService">
<ref bean="authenticationDao"/>
</property>
</bean><bean id="authenticationDao" class="org.acegisecurity.userdetails.memory.InMemoryDaoImpl">
<property name="userMap">
<value>
hhh=hhh,ROLE_MANAGER
gcm=gcm,disable,ROLE_LEADER
</value>
</property>
</bean><bean id="passwordEncoder" class="org.acegisecurity.providers.encoding.Md5PasswordEncoder">
</bean>
<bean id="authenticationManager" class="org.acegisecurity.providers.ProviderManager">
<property name="providers">
<list>
<ref bean="authenticationProvider"/>
</list>
</property>
</bean><bean id="voter" class="org.acegisecurity.vote.RoleVoter">
<property name="rolePrefix">
<value>ROLE_</value>
</property>
</bean><bean id="accessDecisionManager" class="org.acegisecurity.vote.AffirmativeBased">
<property name="decisionVoters">
<list>
<ref bean="voter"/>
</list>
</property>
</bean>
 <bean id="filterInvocationInterceptor" class="org.acegisecurity.intercept.web.FilterSecurityInterceptor">
        <property name="authenticationManager" ref="authenticationManager"/>
        <property name="accessDecisionManager" ref="accessDecisionManager"/>
        <property name="objectDefinitionSource">
        <value>
CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
PATTERN_TYPE_APACHE_ANT
/**=ROLE_MANAGER,ROLE_LEADER
        </value>
        </property>
    </bean>
<!--登录时的入口 -->
<bean id="base" class="org.acegisecurity.ui.basicauth.BasicProcessingFilterEntryPoint">
<property name="realmName">
<value>hhh</value>
</property>
</bean>
<bean id="baseProcessingFilter" class="org.acegisecurity.ui.basicauth.BasicProcessingFilter">
<property name="authenticationManager">
<ref bean="authenticationManager"/>
</property>
<property name="authenticationEntryPoint">
<ref bean="base"/>
</property>
</bean>
    <bean id="filterChainProxy" class="org.acegisecurity.util.FilterChainProxy">
        <property name="filterInvocationDefinitionSource">
            <value>
                CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
                PATTERN_TYPE_APACHE_ANT
                /**=httpSessionContextIntegrationFilter,baseProcessingFilter,filterInvocationInterceptor
            </value>
        </property>
    </bean>
</beans>web.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" 
xmlns="http://java.sun.com/xml/ns/j2ee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:security.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<filter>
        <filter-name>Acegi Filter Chain Proxy</filter-name>
        <filter-class>org.acegisecurity.util.FilterToBeanProxy</filter-class>
        <init-param>
            <param-name>targetClass</param-name>
            <param-value>org.acegisecurity.util.FilterChainProxy</param-value>
        </init-param>
    </filter>

<filter-mapping>
<filter-name>Acegi Filter Chain Proxy</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>