Spring redis cache清除缓存所有key

static class RedisCacheCleanByPrefixCallback extends LockingRedisCacheCallback {

        private static final byte[] REMOVE_KEYS_BY_PATTERN_LUA = new StringRedisSerializer().serialize(
                "local keys = redis.call('KEYS', ARGV[1]); local keysCount = table.getn(keys); if(keysCount > 0) then for _, key in ipairs(keys) do redis.call('del', key); end; end; return keysCount;");
        private static final byte[] WILD_CARD = new StringRedisSerializer().serialize("*");
        private final RedisCacheMetadata metadata;

        public RedisCacheCleanByPrefixCallback(RedisCacheMetadata metadata) {
            super(metadata);
            this.metadata = metadata;
        }

        /*
         * (non-Javadoc)
         * @see org.springframework.data.redis.cache.RedisCache.LockingRedisCacheCallback#doInLock(org.springframework.data.redis.connection.RedisConnection)
         */
        @Override
        public Void doInLock(RedisConnection connection) throws DataAccessException {

            byte[] prefixToUse = Arrays.copyOf(metadata.getKeyPrefix(), metadata.getKeyPrefix().length + WILD_CARD.length);
            System.arraycopy(WILD_CARD, 0, prefixToUse, metadata.getKeyPrefix().length, WILD_CARD.length);

            if (isClusterConnection(connection)) {

                // load keys to the client because currently Redis Cluster connections do not allow eval of lua scripts.
                Set keys = connection.keys(prefixToUse);
                if (!keys.isEmpty()) {
                    connection.del(keys.toArray(new byte[keys.size()][]));
                }
            } else {
                connection.eval(REMOVE_KEYS_BY_PATTERN_LUA, ReturnType.INTEGER, 0, prefixToUse);
            }

            return null;
        }
    }

从上面的代码片段可以看到，spring利用lua在redis中中完成清除指定prefix的keys。