spring mvc中 shiro logout 配置方式

( 我用的是spring mvc下的shiro集成 这点强调一下
<dependency>
            <groupId>org.apache.shiro</groupId>
            <artifactId>shiro-spring</artifactId>
            <version>${shiro.version}</version>
        </dependency>
)
有两种方式实现logout
1. 普通的action中 实现自己的logout方法，取到Subject，然后logout
这种需要在ShiroFilterFactoryBean 中配置 filterChainDefinitions
对应的action的url为anon
<property name="filterChainDefinitions">
            <value>
                # some example chain definitions:
                /index.htm = anon
                /logout = anon
                /unauthed = anon
                /console/** = anon
                /css/** = anon
                /js/** = anon
                /lib/** = anon
                /admin/** = authc, roles[admin]
                /docs/** = authc, perms[document:read]
                /** = authc
                # more URL-to-FilterChain definitions here
            </value>

2. 使用shiro提供的logout filter
需要定义 相应的bean
<bean id="logout" class="org.apache.shiro.web.filter.authc.LogoutFilter">
        <property name="redirectUrl" value="/loginform" />
    </bean>

然后将相应的url filter配置为logout如下
<property name="filterChainDefinitions">
            <value>
                # some example chain definitions:
                /index.htm = anon
                /logout = logout
                /unauthed = anon
                /console/** = anon
                /css/** = anon
                /js/** = anon
                /lib/** = anon
                /admin/** = authc, roles[admin]
                /docs/** = authc, perms[document:read]
                /** = authc
                # more URL-to-FilterChain definitions here
            </value>