使用CAS服务器实现单点登录

先导入单点登录依赖

	<!-- 配置单点登录的依赖 -->
	<dependency>
		<groupId>org.springframework.security</groupId>
		<artifactId>spring-security-web</artifactId>
		<version>4.1.0.RELEASE</version>
	</dependency>
	<dependency>
		<groupId>org.springframework.security</groupId>
		<artifactId>spring-security-config</artifactId>
		<version>4.1.0.RELEASE</version>
	</dependency>
  	<dependency>  
	   <groupId>org.springframework.security</groupId>  
	   <artifactId>spring-security-cas</artifactId>  
	   <version>4.1.0.RELEASE</version>  
	</dependency>     
	<dependency>  
        <groupId>org.jasig.cas.client</groupId>  
        <artifactId>cas-client-core</artifactId>  
        <version>3.3.3</version>  
        <exclusions>  
            <exclusion>  
                <groupId>org.slf4j</groupId>  
                <artifactId>log4j-over-slf4j</artifactId>  
            </exclusion>  
        </exclusions>  
	</dependency>

web.xml中配置监听security.xml的代码

	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:spring/spring-security.xml</param-value>
	 </context-param>
	 <listener>
		<listener-class>
			org.springframework.web.context.ContextLoaderListener
		</listener-class>
	 </listener>	
	 <filter>  
		<filter-name>springSecurityFilterChain</filter-name>  		
		<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>  
	 </filter>  
	 <filter-mapping>  
		<filter-name>springSecurityFilterChain</filter-name>  
		<url-pattern>/*</url-pattern>  
	 </filter-mapping>

配置一个认证类且实现UserDetailsService接口

package com.fzx.service;

import java.util.ArrayList;
import java.util.List;

import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;

import com.alibaba.dubbo.config.annotation.Reference;
import com.fzx.pojo.TbUser;
import com.fzx.user.service.UserService;
/**
 * 认证类
 * @author xu001
 *
 */
public class UserDetailsServiceImpl implements UserDetailsService {

	@Reference
	private UserService userService;
	
	@Override
	public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
		// TODO Auto-generated method stub
		System.out.println("search......UserDetailsService......");
		//构建角色列表
		List<GrantedAuthority> grantedAuthorities = new ArrayList<GrantedAuthority>();
		grantedAuthorities.add(new SimpleGrantedAuthority("ROLE_BUYER"));
		TbUser user = userService.findByUsername(username);
		//得到商家对象
		if (user != null) {
			if(user.getStatus()!=null && user.getStatus().endsWith("1")) {
				//封禁的账号
				return null;
			}
			return new User(username,user.getPassword(),grantedAuthorities);
		}
		return null;
	}

}

在根路径下创建一个spring-security.xml文件

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

	<!-- 这是允许访问或放行的页面 -->
	<http pattern="/css/**" security="none"></http>
	<http pattern="/img/**" security="none"></http>
	<http pattern="/js/**" security="none"></http>
	<http pattern="/plugins/**" security="none"></http>
	<http pattern="/*.html" security="none"></http>
	
	<!-- 页面拦截规则 -->
	<http use-expressions="false" entry-point-ref="casProcessingFilterEntryPoint">
		<!-- 放行所有的html页面 -->
		<intercept-url pattern="/*.html" access="IS_AUTHENTICATED_ANONYMOUSLY"/>
		<!-- 拦截所有 -->
		<intercept-url pattern="/**" access="ROLE_BUYER"/>
		<csrf disabled="true"/> 
		
		<!-- custom-filter为过滤器， position 表示将过滤器放在指定的位置上，before表示放在指定位置之前  ，after表示放在指定的位置之后  -->           
        <custom-filter ref="casAuthenticationFilter"  position="CAS_FILTER" />      
        <custom-filter ref="requestSingleLogoutFilter" before="LOGOUT_FILTER"/>  
        <custom-filter ref="singleLogoutFilter" before="CAS_FILTER"/> 
		
		<headers>
			<frame-options policy="SAMEORIGIN"/><!-- 不写这个登录之后会页面空白 -->
		</headers>
	</http>
	
	 <!-- 引用dubbo 服务 -->
	<dubbo:application name="fzx-search-web" />
	<dubbo:registry address="zookeeper://192.168.25.130:2181"/>
	<dubbo:annotation package="com.fzx.service" />  
	
	<!-- <dubbo:reference id="sellerService" interface="com.fzx.sellergoods.service.SellerService"></dubbo:reference>
	
	<beans:bean id="userDetailService" class="com.fzx.service.UserDetailsServiceImpl">
		<beans:property name="sellerService" ref="sellerService"></beans:property>
	</beans:bean> -->
	
	
	<!-- CAS入口点 开始 -->
    <beans:bean id="casProcessingFilterEntryPoint" class="org.springframework.security.cas.web.CasAuthenticationEntryPoint">  
        <!-- 单点登录服务器登录URL -->  
        <beans:property name="loginUrl" value="http://localhost:9100/cas/login"/>  
        <beans:property name="serviceProperties" ref="serviceProperties"/>  
    </beans:bean>      
    <beans:bean id="serviceProperties" class="org.springframework.security.cas.ServiceProperties">  
        <!--service 配置自身工程的根地址+/login/cas   -->  
        <beans:property name="service" value="http://localhost:9104/login/cas"/>
    </beans:bean>  
    <!-- CAS入口点 结束 -->
    
     <!-- 认证过滤器 开始 -->
    <beans:bean id="casAuthenticationFilter" class="org.springframework.security.cas.web.CasAuthenticationFilter">  
        <beans:property name="authenticationManager" ref="authenticationManager"/>  
    </beans:bean>  
		<!-- 认证管理器 -->
	<authentication-manager alias="authenticationManager">
		<authentication-provider  ref="casAuthenticationProvider">
		</authentication-provider>
	</authentication-manager>
		<!-- 认证提供者 -->
	<beans:bean id="casAuthenticationProvider"     class="org.springframework.security.cas.authentication.CasAuthenticationProvider">  
        <beans:property name="authenticationUserDetailsService">  
            <beans:bean class="org.springframework.security.core.userdetails.UserDetailsByNameServiceWrapper">  
                <beans:constructor-arg ref="userDetailsService" />  
            </beans:bean>  
        </beans:property>  
        <beans:property name="serviceProperties" ref="serviceProperties"/>  
        <!-- ticketValidator 为票据验证器 -->
        <beans:property name="ticketValidator">  
            <beans:bean class="org.jasig.cas.client.validation.Cas20ServiceTicketValidator">  
                <beans:constructor-arg index="0" value="http://localhost:9100/cas"/>  
            </beans:bean>  
        </beans:property>  
        <beans:property name="key" value="an_id_for_this_auth_provider_only"/> 
    </beans:bean>        
   		 <!-- 认证类 -->
	<beans:bean id="userDetailsService" class="com.fzx.service.UserDetailsServiceImpl"/>  
	
	<!-- 认证过滤器 结束 -->
	<!-- 单点登出  开始  -->     
    <beans:bean id="singleLogoutFilter" class="org.jasig.cas.client.session.SingleSignOutFilter"/>          
    <beans:bean id="requestSingleLogoutFilter" class="org.springframework.security.web.authentication.logout.LogoutFilter">  
        <beans:constructor-arg value="http://localhost:9100/cas/logout?service=http://localhost:9103"/>  
        <beans:constructor-arg>  
            <beans:bean class="org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler"/>  
        </beans:constructor-arg>  
        <beans:property name="filterProcessesUrl" value="/logout/cas"/>  
    </beans:bean>  
    <!-- 单点登出  结束 -->
</beans:beans>

小生此为初学者，能力有限，如若哪位大神觉得小生哪里做的不对，还望大神指点一二……