spring session同域下单点登录实现解析

pom.xml<dependency>  <groupId>org.springframework.session</groupId>  <artifactId>spring-session-data-redis</artifactId>  <version>1.3.1.RELEASE</version></dependency>web.xml　　<filter>    <filter-name>springSessionRepositoryFilter</filter-name>    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>  </filter>  <filter-mapping>    <filter-name>springSessionRepositoryFilter</filter-name>    <url-pattern>*.do</url-pattern>  </filter-mapping>　　<listener>    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>  </listener>  <context-param>    <param-name>contextConfigLocation</param-name>    <param-value>      classpath:applicationContext.xml    </param-value>  </context-param>applicationContext.xml  <context:annotation-config/>  <!-- 初始化一切spring-session准备，且把springSessionFilter放入IOC -->  <bean id="redisHttpSessionConfiguration" class="org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration">    <property name="maxInactiveIntervalInSeconds" value="300"/>  </bean>　　<!-- 配置cookie信息-->  <bean class="org.springframework.session.web.http.DefaultCookieSerializer" id="defaultCookieSerializer">    <property name="cookieName" value="SESSION_NAME"/>    <property name="domainName" value="wangjun.com"/>    <property name="useHttpOnlyCookie" value="true"/>    <property name="cookiePath" value="/"/>    <property name="cookieMaxAge" value="31536000"/>  </bean>　　<!-- 配置redis连接池信息-->　　  <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">    <property name="maxTotal" value="20"/>  </bean>　　<!--配置redis连接信息-->  <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">    <property name="hostName" value="127.0.0.1"/>    <property name="port" value="6379"/>    <property name="poolConfig" ref="jedisPoolConfig"/>  </bean>

public class SessionServlet extends HttpServlet {   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    this.doGet(request,response);  }   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    String sesssionID = request.getSession().getId();    //部署两份，把这个地方8081改成8080就行了，只是为了区分    response.getWriter().write("8081 Server SessionID"+sesssionID);  }}