springboot 整合 session，实现 session 共享

前言

session 和 cookie 是保存用户状态的两种方式，session在服务端，cookie 在客户端。
本文章将记录 springboot 整合 session 的 demo 示例。

session（会话）

• 粘性会话
  如果某台服务器宕机，那么会话信息就没有了。
• 复制会话
  每台机器都复制会话，如果量太大的话，不现实
• 集中会话
  使用 mongo 、redis 等统一保持会话

pom 依赖

	
			org.springframework.boot
			spring-boot-starter-web
		
		
			org.springframework.boot
			spring-boot-starter-data-redis
		
		
			org.springframework.session
			spring-session-core
		
		
			org.springframework.session
			spring-session-data-redis
		
		
			org.springframework.boot
			spring-boot-starter-test
			test
		

启动类

@SpringBootApplication
@RestController
@EnableRedisHttpSession
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(SessionDemoApplication.class, args);
	}
	@RequestMapping("/hello")
	public String printSession(HttpSession session, String name) {
		String storedName = (String) session.getAttribute("name");
		if (storedName == null) {
			session.setAttribute("name", name);
			storedName = name;
		}
		return "hello " + storedName;
	}

}

@EnableRedisHttpSession 使用这个注解，开启 httpsession redis 的自动配置

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Import(RedisHttpSessionConfiguration.class)
@Configuration
public @interface EnableRedisHttpSession {
}

然后看一下 RedisHttpSessionConfiguration

@Configuration
@EnableScheduling
public class RedisHttpSessionConfiguration extends SpringHttpSessionConfiguration
		implements BeanClassLoaderAware, EmbeddedValueResolverAware, ImportAware,
		SchedulingConfigurer {

	static final String DEFAULT_CLEANUP_CRON = "0 * * * * *";

	private Integer maxInactiveIntervalInSeconds = MapSession.DEFAULT_MAX_INACTIVE_INTERVAL_SECONDS;

	private String redisNamespace = RedisOperationsSessionRepository.DEFAULT_NAMESPACE;

	private RedisFlushMode redisFlushMode = RedisFlushMode.ON_SAVE;

	private String cleanupCron = DEFAULT_CLEANUP_CRON;

	private ConfigureRedisAction configureRedisAction = new ConfigureNotifyKeyspaceEventsAction();

	private RedisConnectionFactory redisConnectionFactory;

	private RedisSerializer