什么是SSO?

*的解释是：

 个人理解：

    我们刚学javaweb所写的程序都是一些比较小的用来练手学习的程序，所有的系统都在一个tomcat内完成，在一个tomcat内session可以共享，之后在企业项目都会被拆分成分布式的项目，也就是每个系统都是一个单独的项目，这种情况下session不能共享，那么如何保存用户的登录信息，于是我们就要用到SSO单点登录系统。我们平时用的支付宝，淘宝等阿里的产品，只需要登录一次就可以使用其各个其他产品，这也是单点登陆在大型互联网企业里的应用。即所谓的“一次登录，处处使用”，下面就介绍下单点登录的实现过程。

传统登录流程

（图片来源黑马程序员教学视频）

 单点登陆的流程

 Java语言实现过程

1.首先创建maven工程，然后导入依赖jar包。

<dependencies>
		
		<!-- 单元测试 -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<scope>test</scope>
		</dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-jdbc</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aspects</artifactId>
		</dependency>

		<!-- Mybatis -->
		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis</artifactId>
		</dependency>
		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis-spring</artifactId>
		</dependency>
		<!-- 通用Mapper -->
		<dependency>
			<groupId>com.github.abel533</groupId>
			<artifactId>mapper</artifactId>
		</dependency>

		<!-- MySql -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>

		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-log4j12</artifactId>
		</dependency>

		<!-- jedis依赖包，用来做redis相关的-->
		<dependency>
			<groupId>redis.clients</groupId>
			<artifactId>jedis</artifactId>
			<version>2.6.0</version>
		</dependency>

		<!-- Jackson Json处理工具包 -->
		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
		</dependency>

		<!-- 连接池 -->
		<dependency>
			<groupId>com.jolbox</groupId>
			<artifactId>bonecp-spring</artifactId>
		</dependency>

		<!-- JSP相关 -->
		<dependency>
			<groupId>jstl</groupId>
			<artifactId>jstl</artifactId>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>servlet-api</artifactId>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jsp-api</artifactId>
			<scope>provided</scope>
		</dependency>

		<!-- Apache工具组件 -->
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-lang3</artifactId>
		</dependency>
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-io</artifactId>
		</dependency>

		<!-- 加密解密的工具 -->
		<dependency>
			<groupId>commons-codec</groupId>
			<artifactId>commons-codec</artifactId>
			<version>1.9</version>
		</dependency>
		
		<!-- 数据校验 -->
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-validator</artifactId>
			<version>5.1.3.Final</version>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<!-- 配置Tomcat插件 -->
			<plugin>
				<groupId>org.apache.tomcat.maven</groupId>
				<artifactId>tomcat7-maven-plugin</artifactId>
				<configuration>
					<port>8083</port>
					<path>/</path>
				</configuration>
			</plugin>
		</plugins>
	</build>

这里的maven继承了一个父工程，里面定义好了各种依赖的版本号，因此子工程里不需要定义了版本号了

2.生成web.xml,编写springmvc入口等等操作。

<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:spring/applicationContext*.xml</param-value>
	</context-param>

	<!--Spring的ApplicationContext 载入 -->
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

	<!-- 编码过滤器，以UTF8编码 -->
	<filter>
		<filter-name>encodingFilter</filter-name>
		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>UTF8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>encodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	<!-- 配置SpringMVC框架入口 -->
	<servlet>
		<servlet-name>taotao-sso</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:spring/taotao-sso-servlet.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>taotao-sso</servlet-name>
		<url-pattern>*.html</url-pattern>
	</servlet-mapping>

	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
	</welcome-file-list>

3.搭建SSM环境的配置环境。

  首先是spring的主配置文件applicationContext.xml（加载文件，配置基础扫描包，添加数据源）

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	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-4.0.xsd
	http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
	http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
	http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

	<!-- 使用spring自带的占位符替换功能 -->
	<bean
		class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<!-- 允许JVM参数覆盖 -->
		<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
		<!-- 忽略没有找到的资源文件 -->
		<property name="ignoreResourceNotFound" value="true" />
		<!-- 配置资源文件 -->
		<property name="locations">
			<list>
				<value>classpath:jdbc.properties</value>
				<value>classpath:env.properties</value>
				<value>classpath:redis.properties</value>
			</list>
		</property>
	</bean>
	
	<!-- 扫描包，将相关的bean注入spring，交由spring管理 -->
	<context:component-scan base-package="com.taotao"/>

	 <!-- 定义数据源 -->
	<bean id="dataSource" class="com.jolbox.bonecp.BoneCPDataSource"
		destroy-method="close">
		<!-- 数据库驱动 -->
		<property name="driverClass" value="${jdbc.driverClassName}" />
		<!-- 相应驱动的jdbcUrl -->
		<property name="jdbcUrl" value="${jdbc.url}" />
		<!-- 数据库的用户名 -->
		<property name="username" value="${jdbc.username}" />
		<!-- 数据库的密码 -->
		<property name="password" value="${jdbc.password}" />
		<!-- 检查数据库连接池中空闲连接的间隔时间，单位是分，默认值：240，如果要取消则设置为0 -->
		<property name="idleConnectionTestPeriod" value="60" />
		<!-- 连接池中未使用的链接最大存活时间，单位是分，默认值：60，如果要永远存活设置为0 -->
		<property name="idleMaxAge" value="30" />
		<!-- 每个分区最大的连接数 -->
		<!-- 
			判断依据：请求并发数
		 -->
		<property name="maxConnectionsPerPartition" value="100" />
		<!-- 每个分区最小的连接数 -->
		<property name="minConnectionsPerPartition" value="5" />
	</bean>

</beans>

配置springmvc整合文件sso-servlet.xml（注解驱动，扫描controller包，视图解析器页面跳转）

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

	<!-- 注解驱动 -->
	<mvc:annotation-driven>
		<!-- 添加jsonp统一支持。 -->
		<mvc:message-converters register-defaults="true">
			<bean
				class="com.taotao.sso.util.CallBackMappingJackson2HttpMessageConvert">
				<property name="callbackName" value="callback" />
			</bean>
		</mvc:message-converters>
	</mvc:annotation-driven>

	<!-- 扫描包 -->
	<context:component-scan base-package="com.taotao.sso.controller" />

	<!-- 视图解析器 -->
	<!-- Example: prefix="/WEB-INF/jsp/", suffix=".jsp", viewname="test" -> 
		"/WEB-INF/jsp/test.jsp" -->
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/views/" />
		<property name="suffix" value=".jsp" />
	</bean>

</beans>

配置spring事务管理context-transaction.xml（事务管理器，策略，增强切入点）

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	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-4.0.xsd
	http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
	http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
	http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
	
	<!-- 定义事务管理器 -->
	<bean id="transactionManager"
		class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource" />
	</bean>

	<!-- 定义事务策略 -->
	<tx:advice id="txAdvice" transaction-manager="transactionManager">
		<tx:attributes>
			<!--所有以query开头的方法都是只读的 -->
			<tx:method name="query*" read-only="true" />
			<!--其他方法使用默认事务策略 -->
			<tx:method name="*" />
		</tx:attributes>
	</tx:advice>

	<aop:config>
		<!--pointcut元素定义一个切入点，execution中的第一个星号 用以匹配方法的返回类型，
			这里星号表明匹配所有返回类型。 com.abc.dao.*.*(..)表明匹配cn.itcast.mybatis.service包下的所有类的所有 
			方法 -->
		<aop:pointcut id="myPointcut" expression="execution(* com.taotao.sso.service.*.*(..))" />
		<!--将定义好的事务处理策略应用到上述的切入点 -->
		<aop:advisor advice-ref="txAdvice" pointcut-ref="myPointcut" />
	</aop:config>
	
</beans>

配置spring和redis整合文件spring-redis.xml(redis集群配置，连接池配置)

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	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-4.0.xsd
	http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
	http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
	http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

	<!-- 集群的配置 -->
	<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
		<!-- 最大连接数 -->
		<property name="maxTotal" value="${redis.maxTotal}" />
	</bean>

	<!-- 集群连接池 -->
	<bean id="shardedJedisPool" class="redis.clients.jedis.ShardedJedisPool">
		<constructor-arg index="0" ref="jedisPoolConfig" />
		<constructor-arg index="1">
			<list>
				<bean class="redis.clients.jedis.JedisShardInfo">
					<constructor-arg index="0" value="${redis.node1.host}"/>
					<constructor-arg index="1" value="${redis.node1.port}"/>
				</bean>
			</list>
		</constructor-arg>
	</bean>

</beans>

配置spring和mybaits整合文件spring-mybatis（配置sqlSessionFactory,mapper扫描代理）

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	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-4.0.xsd
	http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
	http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
	http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

	<!-- 定义sqlSessionFactory -->
	<bean class="org.mybatis.spring.SqlSessionFactoryBean">
		<!-- 配置数据源 -->
		<property name="dataSource" ref="dataSource"/>
		<!-- 配置mybatis的全局配置文件 -->
		<property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/>
		<!-- 配置mapper.xml文件扫描路径 -->
		<!-- <property name="mapperLocations" value="classpath:mybatis/mappers/**/*.xml"/> -->
		<!-- 配置别名包 -->
		<property name="typeAliasesPackage" value="com.taotao.sso.pojo"/>
	</bean>
	
	<!-- 配置mapper接口扫描包 -->
	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<property name="basePackage" value="com.taotao.sso.mapper"/>
	</bean>

</beans>

4.编写dao层，这里使用的是通用mapper，直接继承通用mapper的Mapper接口类就行了。就省略了，通用mapper的用法前几期文章有介绍过有兴趣可以去看看。

5.编写service层。

package com.taotao.sso.service.impl;

import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.taotao.sso.mapper.UserMapper;
import com.taotao.sso.pojo.User;
import com.taotao.sso.service.RedisService;
import com.taotao.sso.service.UserService;

@Service("userService")
public class UserServiceImpl implements UserService {
	@Autowired
	private UserMapper userMapper;
	
	@Autowired
	private RedisService redisService;
	
	private static final ObjectMapper MAPPER=new ObjectMapper();
	
	@Override
	public String doLogin(String username, String password) throws Exception {
		User record=new User();
		record.setUsername(username);
		User user=this.userMapper.selectOne(record);
		if(null == user){
			return null;
		}
		if(! StringUtils.equals(DigestUtils.md5Hex(password), user.getPassword())){
			return null;
		}
		
		//登录成功
		String token=DigestUtils.md5Hex(System.currentTimeMillis()+username);
		this.redisService.set("token"+token, MAPPER.writeValueAsString(user),60*30);
		
		return token;
	}

}

redisService和一些CookieUtils工具类

package com.taotao.sso.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import redis.clients.jedis.ShardedJedis;
import redis.clients.jedis.ShardedJedisPool;

@Service
public class RedisService {

    @Autowired(required = false)//运行的Spring环境中如果存在就注入，没有就忽略
    private ShardedJedisPool shardedJedisPool;

    private <T> T execute(Function<T, ShardedJedis> fun) {
        ShardedJedis shardedJedis = null;
        try {
            // 从连接池中获取到jedis分片对象
            shardedJedis = shardedJedisPool.getResource();
            return fun.callback(shardedJedis);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != shardedJedis) {
                // 关闭，检测连接是否有效，有效则放回到连接池中，无效则重置状态
                shardedJedis.close();
            }
        }
        return null;
    }

    /**
     * 执行set操作
     * 
     * @param key
     * @param value
     * @return
     */
    public String set(final String key, final String value) {
        return this.execute(new Function<String, ShardedJedis>() {
            @Override
            public String callback(ShardedJedis e) {
                return e.set(key, value);
            }
        });
    }

    /**
     * 执行GET操作
     * 
     * @param key
     * @return
     */
    public String get(final String key) {
        return this.execute(new Function<String, ShardedJedis>() {
            @Override
            public String callback(ShardedJedis e) {
                return e.get(key);
            }
        });
    }

    /**
     * 执行DEL操作
     * 
     * @param key
     * @return
     */
    public Long del(final String key) {
        return this.execute(new Function<Long, ShardedJedis>() {
            @Override
            public Long callback(ShardedJedis e) {
                return e.del(key);
            }
        });
    }

    /**
     * 设置生存时间，单位为秒
     * 
     * @param key
     * @param seconds
     * @return
     */
    public Long expire(final String key, final Integer seconds) {
        return this.execute(new Function<Long, ShardedJedis>() {
            @Override
            public Long callback(ShardedJedis e) {
                return e.expire(key, seconds);
            }
        });
    }

    /**
     * 执行set操作并且设置生存时间，单位为秒
     * 
     * @param key
     * @param value
     * @return
     */
    public String set(final String key, final String value, final Integer seconds) {
        return this.execute(new Function<String, ShardedJedis>() {
            @Override
            public String callback(ShardedJedis e) {
                String str = e.set(key, value);
                e.expire(key, seconds);
                return str;
            }
        });
    }

}


package com.taotao.sso.service;

public interface Function<T, E> {

    public T callback(E e);

}


package com.taotao.sso.util;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * Cookie 工具类
 *
 */
public final class CookieUtils {

    protected static final Logger logger = LoggerFactory.getLogger(CookieUtils.class);

    /**
     * 得到Cookie的值, 不编码
     * 
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName) {
        return getCookieValue(request, cookieName, false);
    }

    /**
     * 得到Cookie的值,
     * 
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName, boolean isDecoder) {
        Cookie[] cookieList = request.getCookies();
        if (cookieList == null || cookieName == null) {
            return null;
        }
        String retValue = null;
        try {
            for (int i = 0; i < cookieList.length; i++) {
                if (cookieList[i].getName().equals(cookieName)) {
                    if (isDecoder) {
                        retValue = URLDecoder.decode(cookieList[i].getValue(), "UTF-8");
                    } else {
                        retValue = cookieList[i].getValue();
                    }
                    break;
                }
            }
        } catch (UnsupportedEncodingException e) {
            logger.error("Cookie Decode Error.", e);
        }
        return retValue;
    }

    /**
     * 得到Cookie的值,
     * 
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName, String encodeString) {
        Cookie[] cookieList = request.getCookies();
        if (cookieList == null || cookieName == null) {
            return null;
        }
        String retValue = null;
        try {
            for (int i = 0; i < cookieList.length; i++) {
                if (cookieList[i].getName().equals(cookieName)) {
                    retValue = URLDecoder.decode(cookieList[i].getValue(), encodeString);
                    break;
                }
            }
        } catch (UnsupportedEncodingException e) {
            logger.error("Cookie Decode Error.", e);
        }
        return retValue;
    }

    /**
     * 设置Cookie的值 不设置生效时间默认浏览器关闭即失效,也不编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue) {
        setCookie(request, response, cookieName, cookieValue, -1);
    }

    /**
     * 设置Cookie的值 在指定时间内生效,但不编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, int cookieMaxage) {
        setCookie(request, response, cookieName, cookieValue, cookieMaxage, false);
    }

    /**
     * 设置Cookie的值 不设置生效时间,但编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, boolean isEncode) {
        setCookie(request, response, cookieName, cookieValue, -1, isEncode);
    }

    /**
     * 设置Cookie的值 在指定时间内生效, 编码参数
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, int cookieMaxage, boolean isEncode) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, isEncode);
    }

    /**
     * 设置Cookie的值 在指定时间内生效, 编码参数(指定编码)
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, int cookieMaxage, String encodeString) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, encodeString);
    }

    /**
     * 删除Cookie带cookie域名
     */
    public static void deleteCookie(HttpServletRequest request, HttpServletResponse response,
            String cookieName) {
        doSetCookie(request, response, cookieName, "", -1, false);
    }

    /**
     * 设置Cookie的值，并使其在指定时间内生效
     * 
     * @param cookieMaxage cookie生效的最大秒数
     */
    private static final void doSetCookie(HttpServletRequest request, HttpServletResponse response,
            String cookieName, String cookieValue, int cookieMaxage, boolean isEncode) {
        try {
            if (cookieValue == null) {
                cookieValue = "";
            } else if (isEncode) {
                cookieValue = URLEncoder.encode(cookieValue, "utf-8");
            }
            Cookie cookie = new Cookie(cookieName, cookieValue);
            if (cookieMaxage > 0)
                cookie.setMaxAge(cookieMaxage);
            if (null != request)// 设置域名的cookie
                cookie.setDomain(getDomainName(request));
            cookie.setPath("/");
            response.addCookie(cookie);
        } catch (Exception e) {
            logger.error("Cookie Encode Error.", e);
        }
    }

    /**
     * 设置Cookie的值，并使其在指定时间内生效
     * 
     * @param cookieMaxage cookie生效的最大秒数
     */
    private static final void doSetCookie(HttpServletRequest request, HttpServletResponse response,
            String cookieName, String cookieValue, int cookieMaxage, String encodeString) {
        try {
            if (cookieValue == null) {
                cookieValue = "";
            } else {
                cookieValue = URLEncoder.encode(cookieValue, encodeString);
            }
            Cookie cookie = new Cookie(cookieName, cookieValue);
            if (cookieMaxage > 0)
                cookie.setMaxAge(cookieMaxage);
            if (null != request)// 设置域名的cookie
                cookie.setDomain(getDomainName(request));
            cookie.setPath("/");
            response.addCookie(cookie);
        } catch (Exception e) {
            logger.error("Cookie Encode Error.", e);
        }
    }

    /**
     * 得到cookie的域名
     */
    private static final String getDomainName(HttpServletRequest request) {
        String domainName = null;

        String serverName = request.getRequestURL().toString();
        if (serverName == null || serverName.equals("")) {
            domainName = "";
        } else {
            serverName = serverName.toLowerCase();
            serverName = serverName.substring(7);
            final int end = serverName.indexOf("/");
            serverName = serverName.substring(0, end);
            final String[] domains = serverName.split("\\.");
            int len = domains.length;
            if (len > 3) {
                // www.xxx.com.cn
                domainName = "." + domains[len - 3] + "." + domains[len - 2] + "." + domains[len - 1];
            } else if (len <= 3 && len > 1) {
                // xxx.com or xxx.cn
                domainName = "." + domains[len - 2] + "." + domains[len - 1];
            } else {
                domainName = serverName;
            }
        }

        if (domainName != null && domainName.indexOf(":") > 0) {
            String[] ary = domainName.split("\\:");
            domainName = ary[0];
        }
        return domainName;
    }

}


package com.taotao.sso.util;

import java.io.IOException;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.converter.HttpMessageNotWritableException;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonProcessingException;

public class CallBackMappingJackson2HttpMessageConvert extends MappingJackson2HttpMessageConverter {
	//做jsonP统一支持标识
	private String callbackName;
	public String getCallbackName() {
		return callbackName;
	}
	public void setCallbackName(String callbackName) {
		this.callbackName = callbackName;
	}
	@Override
	protected void writeInternal(Object object, HttpOutputMessage outputMessage)
			throws IOException, HttpMessageNotWritableException {
		HttpServletRequest request=((ServletRequestAttributes)RequestContextHolder.currentRequestAttributes()).getRequest();
		String callbackParam=request.getParameter(callbackName);
		if(StringUtils.isEmpty(callbackParam)){
			super.writeInternal(object, outputMessage);//调用父类方法直接返回。
		}else{
			JsonEncoding encoding = getJsonEncoding(outputMessage.getHeaders().getContentType());
			try {
				String result =callbackParam+"("+super.getObjectMapper().writeValueAsString(object)+");";
				IOUtils.write(result, outputMessage.getBody(),encoding.getJavaName());
			}
			catch (JsonProcessingException ex) {
				throw new HttpMessageNotWritableException("Could not write JSON: " + ex.getMessage(), ex);
			}
		}
		
		super.writeInternal(object, outputMessage);
	}
	
}

编写controller层

package com.taotao.sso.controller;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.taotao.sso.service.UserService;
import com.taotao.sso.util.CookieUtils;

@RequestMapping("service/user")
@Controller
public class UserController {
	@Autowired
	private UserService userService;
	/**
	 * 注册
	 * @return
	 */
	@RequestMapping(value="/register",method=RequestMethod.GET)
	public String register(){
		return "register";
	}
	
	/**
	 * 登录
	 * @return
	 */
	@RequestMapping(value="/login",method=RequestMethod.GET)
	public String login(){
		return "login";
	}
	
	@RequestMapping(value="/doLogin",method=RequestMethod.POST)
	public Map<String, Object> doLogin(@RequestParam("username") String userName,
			@RequestParam("password")String password,
			HttpServletRequest request,HttpServletResponse response){
		Map<String, Object> result=new HashMap<>();
		try {
			String token=this.userService.doLogin(userName, password);
			if(token != null && !token.isEmpty()){
				result.put("status", 200);
				CookieUtils.setCookie(request,response,"token", token);
			}else{
				result.put("status", 400);//400参数列表错误。
			}
		} catch (Exception e) {
			
			e.printStackTrace();
			result.put("status", 500);
		}
		return result;
	}
}

至此sso系统就写完了。

参考：黑马程序员淘淘商城教学视频。需要资源的可以留言。