What are the annotations for springboot integrated redis?
Introduction to redis:
Redis是当前比较热门的NOSQL系统之一,它是一个开源的使用ANSI c语言编写的key-value存储系统 (区别于MySQL的二维表格的形式存储。)。和Memcache类似,但很大程度补偿了Memcache的不 足。和Memcache一样,Redis数据都是缓存在计算机内存中,不同的是,Memcache只能将数据缓存到 内存中,无法自动定期写入硬盘,这就表示,一断电或重启,内存清空,数据丢失。所以Memcache的 应用场景适用于缓存无需持久化的数据。而Redis不同的是它会周期性的把更新的数据写入磁盘或者把修 改操作写入追加的记录文件,实现数据的持久化。 Redis的特点: 1,Redis读取的速度是110000次/s,写的速度是81000次/s; 2,原子 。Redis的所有操作都是原子性的,同时Redis还支持对几个操作全并后的原子性执行。 3,支持多种数据结构:string(字符串);list(列表);hash(哈希),set(集合);zset(有序集合) 4,持久化,集群部署 5,支持过期时间,支持事务,消息订阅
Introduce dependencies:
<!-- redis --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> <!-- spring2.X集成redis所需common-pool2--> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-pool2</artifactId> <version>2.6.0</version> </dependency>
Write application.properties file
#redi配置 spring.redis.host=ip地址 spring.redis.port=端口号 spring.redis.database=0 spring.redis.password=密码 spring.redis.lettuce.pool.max-active=20 spring.redis.lettuce.pool.max-wait=1 #最大阻塞等待时间(负数表示没有限制) spring.redis.lettuce.pool.max-idle=5 spring.redis.lettuce.pool.min-idle=0 # 关闭超时时间 spring.redis.lettuce.shutdown-timeout=100
Write configuration class :
@EnableCaching @Configuration public class RedisConfig extends CachingConfigurerSupport { @Bean public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<String, Object> template = new RedisTemplate<>(); RedisSerializer<String> redisSerializer = new StringRedisSerializer(); Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); template.setConnectionFactory(factory); //key序列化方式 template.setKeySerializer(redisSerializer); //value序列化 template.setValueSerializer(jackson2JsonRedisSerializer); //value hashmap序列化 template.setHashValueSerializer(jackson2JsonRedisSerializer); return template; } @Bean public CacheManager cacheManager(RedisConnectionFactory factory) { RedisSerializer<String> redisSerializer = new StringRedisSerializer(); Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); //解决查询缓存转换异常的问题 ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); // 配置序列化(解决乱码的问题),过期时间600秒 RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig() .entryTtl(Duration.ofSeconds(600)) .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redi sSerializer)) .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(ja ckson2JsonRedisSerializer)) .disableCachingNullValues(); RedisCacheManager cacheManager = RedisCacheManager.builder(factory) .cacheDefaults(config) .build(); return cacheManager; } }
Springboot’s redis annotation introduction
(1) Cache @Cacheable
Cache the return result according to the method. The next time you request it, if the cache exists, then Directly read the cache data and return; if the cache does not exist, execute the method and store the returned result in the cache. Generally used in query methods.
View the source code, the attribute value is as follows:
(2) Cache @CachePut
is marked with this annotation The method will be called every time it is executed, and the results will be saved to the specified cache. Instead of querying the database again, reading the data directly from the response's cache is another approach. Generally used to add new methods.
View the source code, the attribute values are as follows
(3) Cache @CacheEvict
Use this annotation flag Method will clear the specified cache. Generally used to view the source code on the update or delete method, the attribute value is as follows
不能连接redis: (1)关闭liunx防火墙 (2)找到redis配置文件: 修改 protected-mode yes 改为 protected-mode no 注释掉: bind 127.0.0.1
Test
@Cacheable(value = "banner", key = "'selectIndexList'") @Override public List<CrmBanner> selectIndexList() { List<CrmBanner> list = baseMapper.selectList(new QueryWrapper<CrmBanner>().orderByDesc("sort")); return list; } @CacheEvict(value = "banner", allEntries=true) @Override public void removeBannerById(String id) { baseMapper.deleteById(id); }
In redis:
Basic functions:
Query usage: @Cacheable annotation
Modify delete: Use @CacheEvict annotation
Add : Use @CachePut annotation
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