RabbitMQ 是一個消息broker。它的主要概念就是接受和轉發(fā)消息。可以把它當作一個郵局：當向郵箱投遞一封郵件時，你確信郵差最終會將這封郵件投遞到收件人。使用這個比喻，RabbitMQ就是郵箱，郵局和郵差。

RabbitMQ和郵局最大的區(qū)別就是它不處理紙質信件而是處理二進制數據--消息

RabbitMQ和其他消息系統(tǒng)通常都有以下幾個術語：

生產者 ? 發(fā)送消息

? ?

? ?

隊列

消費者

使用python驅動發(fā)送"Hello World!"

pip install pika

第一個測試程序send.py將會向這個隊列發(fā)送單個消息。首要做的是向RabbitMQ Server建立一個連接。

#!/usr/bin/env?python import?pika connection?=?pika.BlockingConnection(pika.ConnectionParameters('localhost')) channel?=?connection.channel()

默認情況下是不能使用guest用戶登錄的

In?[15]:?import?pikaIn?[16]:?credentials=pika.PlainCredentials('xxx','xxx')In?[17]:?parameters=pika.ConnectionParameters(host='172.28.10.71',credentials=credentials)

在發(fā)送消息之前需要確保收件人隊列存在，如果發(fā)送消息到不存在的地點，RabbitMQ將會直接丟棄這個消息。

創(chuàng)建一個用于投遞消息的隊列

channel.queue_declare(queue='hello')

使用RabbitMQ，不能直接發(fā)送一條消息到隊列。它需要經過一個交換機exchange.

channel.basic_publish(exchange='',routing_key='hello',body='Hello?World!') print?"?[x]?Sent?'Hello?World!'"

在退出程序之前we need to make sure the network buffers were flushed and our message was actually delivered to RabbitMQ.只需要關閉連接就行。

connection.close()

完成的程序 send.py

#!/usr/bin/pythonimport?pikaconnection=pika.BlockingConnection(pika.ConnectionParameters(host='localhost')) channel=connection.channel() channel.queue_declare(queue='hello') channel.basic_publish(exchange='',routing_key='hello',body='Hello?World!') print?"[x]?Sent?'Hello?World!'" connection.close()

...............[x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?rabbitmqctl?list_queues Listing?queues?... hello 28

每執(zhí)行一次就往名為hello的隊列中添加一條消息，使用rabbitmqctl list_queues可以查看隊列長度

第二個程序receive.py 將會從這個隊列中接收消息并打印它們

首先需要連接RabbitMQ，然后需要確保隊列存在

channel.queue_declare(queue='hello')

從隊列中接受消息要復雜得多，它的工作方式是向這個隊列訂閱一個callback函數。任何時候，接收到一條消息，callback函數會被pika庫調用

def?callback(ch,?method,?properties,?body):print?"?[x]?Received?%r"?%?(body,)

然后需要告訴RabbitMQ這個特別的函數是需要從hello隊列接收消息

channel.basic_consume(callback,queue='hello',no_ack=True)

最后，引入一個永不結束的循環(huán)等待接收數據并運行callback函數

print?'?[*]?Waiting?for?messages.?To?exit?press?CTRL+C'channel.start_consuming()

receive.py

#!/usr/bin/pythonimport?pikaconnection=pika.BlockingConnection(pika.ConnectionParameters(host='localhost')) channel=connection.channel() channel.queue_declare(queue='hello')print?'[*]?Waiting?for?messages.To?exit?press?CTRL+c'def?callback(ch,method,properties,body):print?"[x]?Received?%r"?%(body,)channel.basic_consume(callback,queue='hello',no_ack=True) channel.start_consuming()

然后測試：

[root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!' [root@test71?rabbitmq]#?python?send.py? [x]?Sent?'Hello?World!'

[root@test71?rabbitmq]#?python?receive.py? [*]?Waiting?for?messages.To?exit?press?CTRL+c [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' [x]?Received?'Hello?World!' ^CTraceback?(most?recent?call?last):File?"receive.py",?line?16,?in?<module>channel.start_consuming()File?"/usr/lib/python2.6/site-packages/pika/adapters/blocking_connection.py",?line?955,?in?start_consumingself.connection.process_data_events()File?"/usr/lib/python2.6/site-packages/pika/adapters/blocking_connection.py",?line?240,?in?process_data_eventsif?self._handle_read():File?"/usr/lib/python2.6/site-packages/pika/adapters/blocking_connection.py",?line?347,?in?_handle_readif?self._read_poller.ready():File?"/usr/lib/python2.6/site-packages/pika/adapters/blocking_connection.py",?line?43,?in?innerreturn?f(*args,?**kwargs)File?"/usr/lib/python2.6/site-packages/pika/adapters/blocking_connection.py",?line?85,?in?readyevents?=?self.poller.poll(self.poll_timeout) KeyboardInterrupt

參考資料：

http://previous.rabbitmq.com/v3_3_x/tutorials/tutorial-one-python.html

轉載于:https://blog.51cto.com/john88wang/1670904

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