redis - Spring Data RedisTemplate，设置值时ttl不起作用

Question

我想为存储在 Redis 中的 key 设置一个 ttl，我是通过以下方式完成的:

@Component
public class RedisBetgeniusMarketService implements BetgeniusMarketService {

    private static final int DEFAULT_EVENTS_LIFE_TIME = 240;

    @Value("${redis.events.lifetime}")
    private long eventsLifeTime = DEFAULT_EVENTS_LIFE_TIME;

    @Autowired
    private RedisTemplate<String, Market> marketTemplate;

    @Override
    public Market findOne(Integer fixtureId, Long marketId) {
        String key = buildKey(fixtureId, marketId);
        return marketTemplate.boundValueOps(key).get();
    }

    @Override
    public void save(Integer fixtureId, Market market) {
        String key = buildKey(fixtureId, market.getId());
        BoundValueOperations<String, Market> boundValueOperations = marketTemplate.boundValueOps(key);
        boundValueOperations.expire(eventsLifeTime, TimeUnit.MINUTES);
        boundValueOperations.set(market);
    }

    private String buildKey(Integer fixtureId, Long marketId) {
        return "market:" + fixtureId + ":" + marketId;
    }
}

但是，当我打印创建的 key 的 ttl 时，它等于 -1。

请告诉我我做错了什么。

模板bean配置如下:

    @Bean
    public RedisTemplate<String, com.egalacoral.spark.betsync.entity.Market> marketTemplate(RedisConnectionFactory connectionFactory) {
        final RedisTemplate<String, com.egalacoral.spark.betsync.entity.Market> redisTemplate = new RedisTemplate<>();
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new Jackson2JsonRedisSerializer(com.egalacoral.spark.betsync.entity.Market.class));
        redisTemplate.setConnectionFactory(connectionFactory);
        return redisTemplate;
    } 

Answer 1

您需要以不同的顺序调用 expire(...) 和 set(...)。 SET命令删除之前应用的任何超时:

来自 http://redis.io/commands/set 处的文档:

Set key to hold the string value. If key already holds a value, it is overwritten, regardless of its type. Any previous time to live associated with the key is discarded on successful SET operation.

在您的情况下，您只需要将 expire(...) 和 set(...) 的顺序切换为 set(...) 和过期(...)。

@Override
public void save(Integer fixtureId, Market market) {
    String key = buildKey(fixtureId, market.getId());
    BoundValueOperations<String, Market> boundValueOperations = marketTemplate.boundValueOps(key);

    boundValueOperations.set(market);
    boundValueOperations.expire(eventsLifeTime, TimeUnit.MINUTES);
}

除此之外，您可以通过在一次调用中设置值和到期时间来改进代码。 ValueOperations (RedisOperations.opsForValue()) 提供了一个set方法，通过签名设置key和timeout

void set(K key, V value, long timeout, TimeUnit unit);