public String getDirectly(final String key) {
        try {
            byte[] ret = client.getData().forPath(key);
            return Objects.isNull(ret) ? null : new String(ret, StandardCharsets.UTF_8);
        } catch (Exception e) {
            throw new ShenyuException(e);
        }
    }
get from zk directly.

@param key zookeeper path
@return value.
shenyu-admin-listener/shenyu-admin-listener-zookeeper/src/main/java/org/apache/shenyu/admin/listener/zookeeper/ZookeeperClient.java