一、模式介紹

話題模式（Topic）基本思想和路由模式是一樣的，只不過路由鍵支持模糊匹配，符號“#”匹配一個或多個詞，符號“*”匹配不多不少一個詞

話題模式相當於消息的模糊匹配，或者按照正則匹配。其中

# 是通配符，匹配一個或者多個單詞

* 代表匹配一個單詞

模式提醒：

當使用#來收消息時，會接收到所有的消息，這樣和fanout模式一樣了。

當routing key中不含*或者#時，則topic的模式退化為direct的一對一模式。

隊列模型：

二、代碼示例

發布者：

 1 #!/usr/bin/env python
 2 import pika
 3 import sys
 4 
 5
 
 connection = pika.BlockingConnection(pika.ConnectionParameters(host=‘localhost‘))
 6 channel = connection.channel()
 7 
 8 channel.exchange_declare(exchange=‘topic_logs‘,
 9                          exchange_type=‘topic‘)
10 
11 routing_key = [‘#‘, "kern.critical", "A critical kernel error"]
12 for i in
 
 range(10):
13     message = ‘{} msg at : routing key {}‘.format(i, routing_key[i % 3])
14     channel.basic_publish(exchange=‘topic_logs‘,
15                           routing_key=routing_key[i % 3],
16                           body=message)
17     print(" [x] Sent :%r" % (message))
18 connection.close()

消費者：

 1 import pika
 2 import sys
 3 
 4 connection = pika.BlockingConnection(pika.ConnectionParameters(host=‘localhost‘))
 5 channel = connection.channel()
 6 
 7 channel.exchange_declare(exchange=‘topic_logs‘,
 8                          exchange_type=‘topic‘)
 9 
10 result = channel.queue_declare(exclusive=True)
11 queue_name = result.method.queue
12 
13 binding_key = "#"
14 
15 channel.queue_bind(exchange=‘topic_logs‘,
16                    queue=queue_name,
17                    routing_key=binding_key)
18 
19 print(‘ [*] Waiting for logs. To exit press CTRL+C‘)
20 
21 def callback(ch, method, properties, body):
22     print(" [x] %r:%r" % (method.routing_key, body))
23 
24 channel.basic_consume(callback,
25                       queue=queue_name,
26                       no_ack=True)
27 
28 channel.start_consuming()

發布者輸出：

[x] Sent :‘0 msg at : routing key #‘
 [x] Sent :‘1 msg at : routing key kern.critical‘
 [x] Sent :‘2 msg at : routing key error.critical‘
 [x] Sent :‘3 msg at : routing key #‘
 [x] Sent :‘4 msg at : routing key kern.critical‘
 [x] Sent :‘5 msg at : routing key error.critical‘
 [x] Sent :‘6 msg at : routing key #‘
 [x] Sent :‘7 msg at : routing key kern.critical‘
 [x] Sent :‘8 msg at : routing key error.critical‘
 [x] Sent :‘9 msg at : routing key #‘

消費者輸出：

all：可以看到接收到所有的消息

[*] Waiting for logs. To exit press CTRL+C
 [x] ‘#‘:b‘0 msg at : routing key #‘
 [x] ‘kern.critical‘:b‘1 msg at : routing key kern.critical‘
 [x] ‘error.critical‘:b‘2 msg at : routing key error.critical‘
 [x] ‘#‘:b‘3 msg at : routing key #‘
 [x] ‘kern.critical‘:b‘4 msg at : routing key kern.critical‘
 [x] ‘error.critical‘:b‘5 msg at : routing key error.critical‘
 [x] ‘#‘:b‘6 msg at : routing key #‘
 [x] ‘kern.critical‘:b‘7 msg at : routing key kern.critical‘
 [x] ‘error.critical‘:b‘8 msg at : routing key error.critical‘
 [x] ‘#‘:b‘9 msg at : routing key #‘

消費者“critical”，只接收含critical的消息

[*] Waiting for logs. To exit press CTRL+C
 [x] ‘kern.critical‘:b‘1 msg at : routing key kern.critical‘
 [x] ‘error.critical‘:b‘2 msg at : routing key error.critical‘
 [x] ‘kern.critical‘:b‘4 msg at : routing key kern.critical‘
 [x] ‘error.critical‘:b‘5 msg at : routing key error.critical‘
 [x] ‘kern.critical‘:b‘7 msg at : routing key kern.critical‘
 [x] ‘error.critical‘:b‘8 msg at : routing key error.critical‘

消費者“kern”，只接收含kern的消息

[*] Waiting for logs. To exit press CTRL+C
 [x] ‘kern.critical‘:b‘1 msg at : routing key kern.critical‘
 [x] ‘kern.critical‘:b‘4 msg at : routing key kern.critical‘
 [x] ‘kern.critical‘:b‘7 msg at : routing key kern.critical‘

三、隊列信息

在管理頁面上可以看到三個隊列信息，routing key對應著三個隊列的配置

python使用rabbitMQ介紹五（話題模式）