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);
  }
}