redis數據到期監聽

在項目中用了redis緩存，緩存的是數據需要設置一個過期時間

1 、首先把數據存如redis並添加失效時間：

public ResultUtil saveDelayEvent(EventInfo info){
    try {
        Map<String,Object> map = new HashMap<>();
        map.put("eventInfo",info);
        Date date = new Date();
        long interval = (info.getDelayDate().getTime() - date.getTime())/1000;
        System.out.println("兩個時間相差"+interval+"秒");
        stringRedisTemplate.opsForValue().set("event_" +info.getId(), map.toString(), interval, TimeUnit.SECONDS);
        return ResultUtil.Ok("保存成功");
    }catch (Exception e){
        e.printStackTrace();
        return ResultUtil.Faild("保存失敗");
    }

}

2、設置失效時間後，要在數據失效的時候監聽到，然後再次存入或者做別的操作

/**
 * redis監聽
 */
@Component
@Slf4j
public class RedisKeyExpirationListener extends KeyExpirationEventMessageListener {



    @Autowired
    private EventInfoTaskDao eventInfoTaskDao;

    @Autowired
    private MessageAPIService messageApi;

    private final String EXCHANGE = "openOne_event";



    /**
     * Creates new {@link } for {@code __keyevent@*__:expired} messages.
     *
     * @param listenerContainer must not be {@literal null}.
     */
    public RedisKeyExpirationListener(RedisMessageListenerContainer listenerContainer) {
        super(listenerContainer);
    }

    /**
     * 針對redis數據失效事件，進行數據處理
     * @param message
     * @param pattern
     */
    @Override
    public void onMessage(Message message, byte[] pattern) {
        //獲得失效的key
        String expiredKey = message.toString();
        if(expiredKey.contains("event_")){
            String eventId = expiredKey.substring(6, expiredKey.length());
            List<EventInfo> task = eventInfoTaskDao.getTask(null, eventId);
            JSONArray json = new JSONArray();
            json.add(task);
            messageApi.sendMessage(EXCHANGE,eventId,json.toJSONString());

        }

    }

另外需要注入bean:

@Configuration
@EnableCaching
@ConditionalOnBean(RedisCacheManager.class)
public class RedisConfig extends CachingConfigurerSupport {

@Bean
public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
   RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();

   // 配置連接工廠
   redisTemplate.setConnectionFactory(redisConnectionFactory);

   // 使用自定義 fastjson 序列化, 作爲 value 值序列化 FastJsonRedisSerializer
   FastJsonRedisSerializer<Object> fastJsonRedisSerializer = new FastJsonRedisSerializer<>(Object.class);

   redisTemplate.setValueSerializer(fastJsonRedisSerializer);
   redisTemplate.setHashValueSerializer(fastJsonRedisSerializer);

   // 使用 StringRedisSerializer 作爲 key 的序列化
   redisTemplate.setKeySerializer(new StringRedisSerializer());
   redisTemplate.setHashKeySerializer(new StringRedisSerializer());

   return redisTemplate;
}

 

@Bean
RedisMessageListenerContainer container(RedisConnectionFactory connectionFactory) {

   RedisMessageListenerContainer container = new RedisMessageListenerContainer();
   container.setConnectionFactory(connectionFactory);
   return container;
}

}