spring-boot-starter-data-redis入门

spring-boot-starter-data-redis

• https://blog.csdn.net/yeyinglingfeng/article/details/87790700?spm=1005.2026.3001.5635&utm_medium=distribute.pc_relevant_ask_down.none-task-blog-2_defaultOPENSEARCH_{default-10.pc_feed_download_top3ask&depth_1-utm_source=distribute.pc_relevant_ask_down.none-task-blog-2}default_OPENSEARCHdefault-10.pc_feed_download_top3ask

依赖 lettuce

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
  <groupId>org.apache.commons</groupId>
  <artifactId>commons-pool2</artifactId>
</dependency>

配置

spring:
  redis:
    host: localhost
    port: 6379
    password: 
    lettuce: 
      pool:## 默认配置
        max-active: 8
        max-idle: 8
        min_idle: 0
        max-wait: -1ms
    cluster:
      nodes:
        - 127.0.0.1:6379
        - 127.0.0.1:6380

序列化

• key序列化 ： StringRedisSerializer
• 值序列换： JdkSerializationRedisSerializer（默认），Jackson2JsonRedisSerializer（推荐）

	@Bean(name = "redisTemplate")
	public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory)
			throws UnknownHostException {
		RedisTemplate<Object, Object> template = new RedisTemplate<>();
		template.setConnectionFactory(redisConnectionFactory);
//		Jackson2JsonRedisSerializer<Object> jackson = new Jackson2JsonRedisSerializer<>(Object.class);
		GenericJackson2JsonRedisSerializer jackson = new GenericJackson2JsonRedisSerializer();
		template.setKeySerializer(RedisSerializer.string());
		template.setKeySerializer(RedisSerializer.string());
		template.setValueSerializer(jackson);
		template.setHashValueSerializer(jackson);
		return template;
	}

• JdkSerializationRedisSerializer 默认，需要对象实现Serializable接口
• Jackson2JsonRedisSerializer 和 GenericJackson2JsonRedisSerializer
  • Jackson2JsonRedisSerializer json序列化。反序列化泛型、数组的数据时为hashmap，因此反序列会报错
  • GenericJackson2JsonRedisSerializer 类json序列化，会存储每个value的数据类型
  • 后者内存消耗大，效率低
• 发布订阅
  • 使用场景：全局缓存（一般redis）和局部缓存（一般为本地jvm内存）的数据同步
  • 命令行: PUBLISH runoobChat "Redis PUBLISH test
  • 命令行： SUBSCRIBE runoobChat

// 发布数据
redisTemplate.convertAndSend(channel, value);

/**
消费订阅数据
*/
 @Bean
 public RedisMessageListenerContainer messageListenerContainer(RedisConnectionFactory redisConnectionFactory, RedisRouteDefinitionListenerHander handler) {

 	RedisMessageListenerContainer container = new RedisMessageListenerContainer();
 	container.setConnectionFactory(redisConnectionFactory);

 	// 可以修改成 patternTopic, 看一看 MessageListener 中监听的数据 msg.getBody是发布的数据
     // msg.getTopic
 	container.addMessageListener(
 			(msg, pattern) -> handler.handle(msg, new String(pattern, StandardCharsets.UTF_8)),
 			new PatternTopic(Constants.REDIS_TOPIC_GATEWAY_PATTERN));
 	return container;
 }

• 分布式锁
  • 命令 SET resource-name anystring NX EX max-lock-time 是一种在 Redis 中实现锁的简单方法。
  • http://doc.redisfans.com/string/set.html
  • ValueOperations.setIfAbsent(key, val, time, unit)
• 自增
  • ValueOperations.increment()
• 消息队列（生产者和消费者模式）
• list map set string
  • http://doc.redisfans.com/string
• 集群部署
• spring-redis