Redis 常用操作

基础数据类型

String 字符串

SET key value
SET key value EX 3600
SET key value PX 60000
SETNX key value
GET key
MGET key1 key2 key3
INCR counter
INCRBY counter 10
DECR counter

Hash 哈希

HSET user:1 name "张三" age 25
HGET user:1 name
HGETALL user:1
HMGET user:1 name age
HDEL user:1 age
HEXISTS user:1 name

List 列表

LPUSH list value
RPUSH list value
LRANGE list 0 -1
LINDEX list 0
LPOP list
RPOP list
BLPOP list 5

Set 集合

SADD set value1 value2
SMEMBERS set
SISMEMBER set value
SINTER set1 set2
SUNION set1 set2
SDIFF set1 set2

ZSet 有序集合

ZADD rank 100 "user1" 90 "user2"
ZRANK rank "user1"
ZREVRANK rank "user1"
ZRANGE rank 0 9 WITHSCORES
ZREVRANGE rank 0 9 WITHSCORES
ZRANGEBYSCORE rank 80 100

Spring Boot 集成

配置

spring:
  data:
    redis:
      host: localhost
      port: 6379
      password:
      database: 0
      lettuce:
        pool:
          max-active: 8
          max-idle: 8
          min-idle: 0

RedisTemplate 使用

@Service
public class RedisService {

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    public void set(String key, Object value, long timeout, TimeUnit unit) {
        redisTemplate.opsForValue().set(key, value, timeout, unit);
    }

    public Object get(String key) {
        return redisTemplate.opsForValue().get(key);
    }

    public Boolean delete(String key) {
        return redisTemplate.delete(key);
    }

    public Boolean hasKey(String key) {
        return redisTemplate.hasKey(key);
    }

    public Boolean expire(String key, long timeout, TimeUnit unit) {
        return redisTemplate.expire(key, timeout, unit);
    }
}

缓存注解

@Service
public class UserService {

    @Cacheable(value = "user", key = "#id")
    public User getById(Long id) {
        return userMapper.selectById(id);
    }

    @CachePut(value = "user", key = "#user.id")
    public User update(User user) {
        userMapper.updateById(user);
        return user;
    }

    @CacheEvict(value = "user", key = "#id")
    public void delete(Long id) {
        userMapper.deleteById(id);
    }
}

分布式锁

Redisson 实现

@Configuration
public class RedissonConfig {

    @Bean
    public RedissonClient redissonClient() {
        Config config = new Config();
        config.useSingleServer()
            .setAddress("redis://localhost:6379");
        return Redisson.create(config);
    }
}

@Service
public class OrderService {

    @Autowired
    private RedissonClient redissonClient;

    public void createOrder(String orderId) {
        RLock lock = redissonClient.getLock("order:" + orderId);
        try {
            if (lock.tryLock(10, 30, TimeUnit.SECONDS)) {
            }
        } finally {
            if (lock.isHeldByCurrentThread()) {
                lock.unlock();
            }
        }
    }
}

常见应用场景

缓存

public User getUserWithCache(Long id) {
    String key = "user:" + id;
    User user = (User) redisTemplate.opsForValue().get(key);
    if (user == null) {
        user = userMapper.selectById(id);
        if (user != null) {
            redisTemplate.opsForValue().set(key, user, 1, TimeUnit.HOURS);
        }
    }
    return user;
}

限流

public boolean allowRequest(String key, int limit, int period) {
    String redisKey = "rate:" + key;
    Long count = redisTemplate.opsForValue().increment(redisKey);
    if (count == 1) {
        redisTemplate.expire(redisKey, period, TimeUnit.SECONDS);
    }
    return count <= limit;
}

最佳实践

1. Key 命名规范: 业务:模块:ID，如 user:profile:1
2. 设置过期时间: 避免内存溢出
3. 避免大 Key: 单个 Key 的 Value 不要超过 10KB
4. 批量操作: 使用 Pipeline 或 Lua 脚本
5. 序列化: 统一使用 JSON 序列化