参考文档： https://github.com/apache/rocketmq/blob/master/docs/cn/RocketMQ_Example.md#2-%E9%A1%BA%E5%BA%8F%E6%B6%88%E6%81%AF%E6%A0%B7%E4%BE%8B https://www.cnblogs.com/xuwc/p/9034352.html
