1. This mode requires RouteKey, and Exchange and Queue must be bound in advance
2. If Exchange does not find a Queue that matches the RouteKey, it will Discard this message
3. When binding, provide a topic that the queue cares about, such as "#.log.#" means that the queue cares about all messages involving log (a message whose RouteKey is "MQ.log.error" will be forwarded to the queue)
4. "#" indicates 0 or several keywords, "*" indicates a keyword. For example, "log.*" can match with "log.warn", but cannot match with "log.warn.timeout"; but "log.#" can match with the above two
reference: http://blog.csdn.net/ csethcrm/article/details/51673050
Example: http://www.cnblogs.com/luxiaoxun/p/3918054.html
Example: http://blog.csdn.net/a491857321/article/details/50616323