关于RabbitMQ 的默认交换机 的问题

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                                       关于RabbitMQ 的默认交换机 的问题

有4个默认的交换机

Name	Default pre-declared names
Direct exchange	(Empty string) and amq.direct
Fanout exchange	amq.fanout
Topic exchange	amq.topic
Headers exchange	amq.match (and amq.headers in RabbitMQ)

Default Exchange

The default exchange is a direct exchange with no name (empty string) pre-declared by the broker.

It has one special property that makes it very useful for simple applications: every queue that is created is automatically bound to it with a routing key which is the same as the queue name.

他有一个特殊的特性对简单应用很有用：每个队列会自动将一个和队列名一致的 Routing  Key 绑定到默认交换机上。

    channel.basicPublish( "", "test_fuzai_queue_1",
            MessageProperties.BASIC,
            message.getBytes());

这个代码的意思是 其实就是将 消息发送到  这个test_fuzai_queue_1队列上

但是其实第二个蚕食其实是 routingKey

For example, when you declare a queue with the name of "search-indexing-online", the AMQP 0-9-1 broker will bind it to the default exchange using "search-indexing-online" as the routing key (in this context sometimes referred to as the binding key). Therefore, a message published to the default exchange with the routing key "search-indexing-online" will be routed to the queue "search-indexing-online". In other words, the default exchange makes it seem like it is possible to deliver messages directly to queues, even though that is not technically what is happening.

要说的是没默认队列，有默认交换机，理论上每个队列能和这个默认交换机绑定，所以说没有交换机也能发送到队列

参考

• https://www.rabbitmq.com/tutorials/amqp-concepts.html