Springboot整合redis实现缓存

引入依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

配置RedisConfig

@EnableCaching
@Configuration
public class RedisConfig {

    @Bean
    RedisCacheConfiguration redisCacheConfiguration() {
        // 读取redis的默认配置模板
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig();

        // 设置过期时间
        config = config.entryTtl(Duration.ofDays(1));

        // 设置KEY的前缀
        config.prefixKeysWith("CACHE_");
        // 开启使用KEY前缀
        config.usePrefix();

        // 设置允许缓存空值，防止缓存穿透
        config.getAllowCacheNullValues();

        // 配置key的序列化方式
        config.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer()));

        // 配置value的序列化方式
        config = config.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer()));

        return config;
    }

}

RedisTemplate常用方法
redisTemplate.opsForValue();//操作字符串
redisTemplate.opsForHash();//操作hash
redisTemplate.opsForList();//操作list
redisTemplate.opsForSet();//操作set
redisTemplate.opsForZSet();//操作有序set

Redis常用缓存注解

注解名 作用
@Cacheable  主要针对方法配置，能够根据方法的请求参数对其结果进行缓存
@CacheEvict 清空缓存
@CachePut   保证方法被调用，又希望结果被缓存
@EnableCaching  开启基于注解的缓存

解决缓存穿透、缓存雪崩、缓存击穿

1. 空结果缓存：解决缓存穿透问题
2. 设置过期时间加随机值：解决缓存雪崩
3. 加锁：解决缓存击穿

Redisson整合 可重入锁 读写锁

官网地址 github redisson wiki

导入依赖

        <dependency>
            <groupId>org.redisson</groupId>
            <artifactId>redisson-spring-boot-starter</artifactId>
             <!--适用于2.2.x版本-->
            <version>3.13.1</version>
        </dependency>

配置RedissonConfig

@Configuration
public class RedissonConfig {

    @Bean
    public RedissonClient redisson() {
        //1. 创建配置
        Config config = new Config();
        config.useSingleServer().setAddress("redis://192.168.56.10:6379");
        // 2. 根据config创建出RedissonClient实例
        RedissonClient redisson = Redisson.create(config);
        return redisson;
    }

}

可重入锁

RLock rLock = redissonClient.getLock("lock");
rLock.lock();
rLock.unlock();

读写锁

    // 读
    @GetMapping("read")
    public R read() {
        RLock lock = redissonClient.getReadWriteLock("rw-lock").readLock();
        try {
            lock.lock();
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
        return R.ok().data("data", "read");
    }

    // 写
    @GetMapping("write")
    public R write() {
        RLock lock = redissonClient.getReadWriteLock("rw-lock").writeLock();
        try {
            lock.lock();
            Thread.sleep(8000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
        return R.ok().data("data", "write");
    }