Python-RabbitMQ消息队列的发布与订阅

RabbitMQ消息队列的发布与订阅类似于广播，一端发送消息，多个客户端可以同时接收到消息

fanout：所有绑定到exchange的queue都可以接收消息

消息发布端

# -*- coding:utf-8 -*-
__author__ = "MuT6 Sch01aR"

import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1'))
channel = connection.channel()

channel.exchange_declare(exchange='fanout_logs', exchange_type='fanout')

message = 'Hello World!'
channel.basic_publish(exchange='fanout_logs',
                      routing_key='',
                      body=message)

print('发送消息：', message)
connection.close()

消息订阅端

# -*- coding:utf-8 -*-
__author__ = "MuT6 Sch01aR"

import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1'))
channel = connection.channel()

channel.exchange_declare(exchange='fanout_logs', exchange_type='fanout')

result = channel.queue_declare(exclusive=True)  # 不指定queue名字,rabbitmq会随机分配一个名字
# exclusive=True会在使用此queue的消息订阅端断开后,自动将queue删除

queue_name = result.method.queue
print('当前queue名称：', queue_name)

channel.queue_bind(exchange='fanout_logs', queue=queue_name)

def callback(ch, method, properties, body):
    print(ch, method, properties)
    print('收到数据：', body)

channel.basic_consume(callback,
                      queue=queue_name,
                      no_ack=True,
                      )

print('开始等待消息')
channel.start_consuming()

消息发布端需要在消息订阅端运行之后运行，不然消息订阅端收不到消息

开启3个消息订阅端和一个消息发布端

消息发布端发布消息

3个消息订阅端会同时接收到消息

direct：指定的queue才能收到消息

把queue绑定关键字，消息发布端根据关键字将消息发送到exchange，exchange根据关键字将消息发送到指定队列

消息发布端

# -*- coding:utf-8 -*-
__author__ = "MuT6 Sch01aR"

import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1'))
channel = connection.channel()

channel.exchange_declare(exchange='direct_logs', exchange_type='direct')

severity = sys.argv[1] if len(sys.argv) > 1 else 'info'  # 关键字
message = 'Hello World!'

channel.basic_publish(exchange='direct_logs',
                      routing_key=severity,
                      body=message)
print('级别 [%s] 发送数据 [%s]' % (severity, message))
connection.close()

消息订阅端

# -*- coding:utf-8 -*-
__author__ = "MuT6 Sch01aR"

import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1'))
channel = connection.channel()

channel.exchange_declare(exchange='direct_logs', exchange_type='direct')

result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue

severities = sys.argv[1:]  # 关键字

for severity in severities:
    channel.queue_bind(exchange='direct_logs',
                       queue=queue_name,
                       routing_key=severity)

def callback(ch, method, properties, body):
    print(ch, method, properties)
    print('收到来自%s的消息：%s' % (method.routing_key, body))

channel.basic_consume(callback,
                      queue=queue_name,
                      no_ack=True)

print('开始等待消息')
channel.start_consuming()

开启3个消息订阅端，分别引用关键字info、warning，warning、error，error、info，开启一个消息发布端，引用关键字wanrning

只有引用关键字warning的消息订阅端才收到消息

没有引用关键字warning的就收不到消息

topic：符合条件的queue才能收到消息

消息订阅端指定条件，符合条件的queue才能被消息订阅端收到消息

#会匹配任意个任意字符串，*会匹配一个任意字符串

单个#会匹配全部字符串，单个*无法匹配

消息发布端

# -*- coding:utf-8 -*-
__author__ = "MuT6 Sch01aR"

import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1'))
channel = connection.channel()

channel.exchange_declare(exchange='topic_logs', exchange_type='topic')

severity = sys.argv[1] if len(sys.argv) > 1 else 'info'
message = 'Hello World!'

channel.basic_publish(exchange='topic_logs',
                      routing_key=severity,
                      body=message)

print('给 [%s] 发送消息 [%s]' % (severity, message))
connection.close()

消息订阅端

# -*- coding:utf-8 -*-
__author__ = "MuT6 Sch01aR"

import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(host='127.0.0.1'))
channel = connection.channel()

channel.exchange_declare(exchange='topic_logs', exchange_type='topic')

result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue

keys = sys.argv[1:]

for key in keys:
    channel.queue_bind(exchange='topic_logs',
                       queue=queue_name,
                       routing_key=key)

def callback(ch, method, properties, body):
    print(ch, method, properties)
    print('来自 [%s] 的信息 [%s]' % (method.routing_key, body))

channel.basic_consume(callback,
                      queue=queue_name,
                      no_ack=True)
print('开始接收消息')
channel.start_consuming()

开启3个消息订阅端和一个消息发布端

3个消息订阅端，一个*.exe匹配以.exe结尾的，一个#匹配全部字符串，一个python.exe只匹配字符串为python.exe的

消息发布端引用关键字qq.exe

很显然，匹配以.exe结尾和匹配全部字符串的消息订阅端将会收到消息，只匹配字符串为python.exe的不会收到消息