单点登录--CAS认证--web.xml配置详解

参考网址：

https://blog.csdn.net/zhurhyme/article/details/29349543

https://blog.csdn.net/shzy1988/article/details/50662462

　　cas 分为服务端，与客户端。那么客户端如何与服务端进行交互呢，或者说服务端发送的response报文客户端如何接收呢？这就要用到配置。cas client通过filter拦截与cas服务器进行交互。它的主要配置主要有以下几个filter:

1.AuthenticationFilter

　　作用，判断用户是否登录，如果登录则进入第二步，否则重定向到cas服务器

2.TicketValidationFilter

　　对于client接收到的ticket进行验证

3.HttpServletRequestWrapperFilter

4.AssertionThreadLocalFilter

<!-- CAS 单点登录(SSO) 过滤器配置 (start) -->  

    <!-- 该过滤器用于实现单点登出功能。-->
    <filter>
        <filter-name>CAS Single Sign Out Filter</filter-name>
        <filter-class>org.jasig.cas.client.session.SingleSignOutFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CAS Single Sign Out Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <!-- CAS: 用于单点退出 -->
    <listener>
        <listener-class>org.jasig.cas.client.session.SingleSignOutHttpSessionListener</listener-class>
    </listener>  

    <!-- 该过滤器负责用户的认证工作，必须启用它 -->
    <filter>
        <filter-name>CASFilter</filter-name>
        <filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class>
        <init-param>
            <param-name>casServerLoginUrl</param-name>
            <!-- 下面的URL是Cas服务器的登录地址 -->
            <param-value>http://CAS服务端所在服务器IP:8080/cas/login</param-value>
        </init-param>
        <init-param>
            <param-name>serverName</param-name>
            <!-- 下面的URL是具体某一个应用的访问地址 -->
            <param-value>http://具体web应用程序所在服务器IP:8080</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CASFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>  

    <!-- 该过滤器负责对Ticket的校验工作，必须启用它 -->
    <filter>
        <filter-name>CAS Validation Filter</filter-name>
        <filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class>
        <init-param>
            <param-name>casServerUrlPrefix</param-name>
            <!-- 下面的URL是Cas服务器的认证地址 -->
            <param-value>http://CAS服务端所在服务器IP:8080/cas</param-value>
        </init-param>
        <init-param>
            <param-name>serverName</param-name>
            <!-- 下面的URL是具体某一个应用的访问地址 -->
            <param-value>http://具体web应用程序所在服务器IP:8080</param-value>
        </init-param>
        <init-param>
          <param-name>renew</param-name>
          <param-value>false</param-value>
        </init-param>
        <init-param>
          <param-name>gateway</param-name>
          <param-value>false</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CAS Validation Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>  

    <!--
    该过滤器负责实现HttpServletRequest请求的包裹，
    比如允许开发者通过HttpServletRequest的getRemoteUser()方法获得SSO登录用户的登录名，可选配置。
    -->
    <filter>
        <filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>
        <filter-class>org.jasig.cas.client.util.HttpServletRequestWrapperFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>  

    <!--
    该过滤器使得开发者可以通过org.jasig.cas.client.util.AssertionHolder来获取用户的登录名。
    比如AssertionHolder.getAssertion().getPrincipal().getName()。
    -->
    <filter>
        <filter-name>CAS Assertion Thread Local Filter</filter-name>
        <filter-class>org.jasig.cas.client.util.AssertionThreadLocalFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CAS Assertion Thread Local Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>  

    <!-- 自动根据单点登录的结果设置本系统的用户信息（具体某一个应用实现） -->
    <filter>
        <filter-name>CasForInvokeContextFilter</filter-name>
        <filter-class>com.cm.demo.filter.CasForInvokeContextFilter</filter-class>
        <init-param>
          <param-name>appId</param-name>
          <param-value>a5ea611bbff7474a81753697a1714fb0</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CasForInvokeContextFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <!-- CAS 单点登录(SSO) 过滤器配置 (end) -->