`rabbitmq`可以通过路由选择订阅者来发布消息。
Bindings
通过下面的函数绑定Exchange与消息队列：
channel.queue_bind(exchange=exchange_name, queue=queue_name)
可以通过添加`routing_key`来做路由选择，如下：
channel.queue_bind(exchange=exchange_name, queue=queue_name, routing_key='black')
Direct Exchange
为了使用直接转发，可以设置`Exchange`的类型为`direct`。
在`rabbitmq`中直接转发的算法很简单，如果`binding key`与`routing key`相同，消息会直接添加到相应的消息队列中取。
Multiple bindings
`rabbitmq`允许一个`Exchange`绑定多个消息队列，那么该`Exchange`会把消息分别发布到绑定的多个消息队列中。
例子
生产者：
#!/usr/bin/env python # coding=utf-8 import pika import sys import time connection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost')) channel = connection.channel() channel.exchange_declare(exchange='news', type='fanout') for i in range(100): message = str(i) + 'Hello World!' if i%2 == 0: channel.basic_publish(exchange='news', routing_key='0', body=message) else: channel.basic_publish(exchange='news', routing_key='1', body=message) print " [x] Sent %r" % (message,) time.sleep(2) connection.close()
消费者：
import pika import sys parameters = pika.URLParameters('amqp://mtest:root@rabbit-server:5672/%2F') connection = pika.BlockingConnection(parameters) channel = connection.channel() channel.exchange_declare(exchange='news', type='fanout') result = channel.queue_declare(exclusive=True) queue_name = result.method.queue channel.queue_bind(exchange='news', queue=queue_name, routing_key=sys.argv[1]) print ' [*] Waiting for news. To exit press CTRL+C' def callback(ch, method, properties, body): print " [x] %r" % (body,) channel.basic_consume(callback, queue=queue_name, no_ack=True) channel.start_consuming()
本文转自cococo点点博客园博客，原文链接：http://www.cnblogs.com/coder2012/p/4342943.html，如需转载请自行联系原作者
