RabbitMQ是一个消息代理，它接受和转发消息，是一个由 Erlang 语言开发的遵循AMQP协议的开源实现。在RabbitMQ中生产者不会将消息直接发送到队列当中，而是将消息直接发送到交换机(exchange)，交换机用来接受生产者发送的消息并将这些消息发送给绑定的队列，即：生产者-->交换机-->队列。
在RabbitMQ中最主要的三种交换机：1. fanout(广播交换机) 2. direct(直连交换机) 3. topic(话题交换机)
1. fanout(广播交换机)
fanout会将接受到的所有消息广播到它所绑定的所有队列当中(每个消费者都会收到所有的消息)，对于广播交换机，消息路由键routing_key和队列绑定键routing_key的作用都会被忽略。
fanout生产者：
import pika class RabbitProducer(object):
"""
与RabbitMq服务器建立连接
""" def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 声明一个exchange交换机,交换机的类型为fanout广播.
self.channel.exchange_declare(
exchange='fanout_exchange', exchange_type='fanout', durable=True
) def send_msg(self, message):
"""
routing_key:绑定的key
:param message:
:return:
"""
self.channel.basic_publish(
exchange='fanout_exchange',
routing_key='', # 因为exchange的类型为fanout,所以routing_key的数值在这里将被忽略
body=message,
properties=pika.BasicProperties(
delivery_mode=2,
# 消息进行持久化(防止服务器挂掉.)===> 如果没有queue绑定到这个exchange交换机,这个参数是没有的.
)) def close(self):
self.conn.close() if __name__ == "__main__":
rabbit_producer = RabbitProducer()
for i in range(10):
message = 'hello world {}!'.format(i)
rabbit_producer.send_msg(message)
消费者consumer1：
import pika
import uuid class RabbitConsumer(object):
"""
fanout 消费者1
""" def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 声明一个队列queue_consumer1,并进行持久化(防止服务器挂掉),exclusive设置为false
self.channel.queue_declare(
exclusive=False, durable=True, queue='queue_consumer1'
) # 声明一个exhange交换机,其类型为fanout广播类型 与生产者的交换机一致
self.channel.exchange_declare(
exchange='fanout_exchange', exchange_type='fanout', durable=True
) # 将队列queue_consumer1与该exchange交换机进行绑定
self.channel.queue_bind(exchange='fanout_exchange', queue='queue_consumer1') def call_back(self, method, body):
"""
消费者对消息进行确认,防止消费者挂掉.
:param method:
:param body:
:return:
"""
self.channel.basic_ack(delivery_tag=method.delivery_tag)
print('接收到的消息为:{}'.format(str(body))) def receive_msg(self):
print('consumer1开始接受消息...')
# 当上一条消息未确认时，会告知RabbitMQ不要再发送消息给这个消费者了 可以控制流量
self.channel.basic_qos(prefetch_count=1)
self.channel.basic_consume(
consumer_callback=self.call_back,
queue='queue_consumer1',
no_ack=False, # 消费者对消息进行确认,防止消费者挂掉
consumer_tag=str(uuid.uuid4())
) def consume(self):
self.receive_msg()
self.channel.start_consuming() if __name__ == '__main__':
rabbit_consumer = RabbitConsumer()
rabbit_consumer.consume()
消费者consumer2：
import pika
import uuid class RabbitConsumer(object):
def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 声明一个队列queue_consumer2,并进行持久化(防止服务器挂掉),exclusive设置为false
self.channel.queue_declare(
exclusive=False, durable=True, queue='queue_consumer2'
) # T声明一个exhange交换机,其类型为fanout广播类型
self.channel.exchange_declare(
exchange='fanout_exchange', exchange_type='fanout', durable=True
) # 将队列queue_consumer2与该exchange交换机进行绑定
self.channel.queue_bind(exchange='fanout_exchange', queue='queue_consumer2') def call_back(self, method, body):
"""
消费者对消息进行确认,防止消费者挂掉.
:param method:
:param body:
:return:
"""
self.channel.basic_ack(delivery_tag=method.delivery_tag)
print('接收到的消息为:{}'.format(str(body))) def receive_msg(self):
print('consumer2开始接受消息...')
self.channel.basic_consume(
consumer_callback=self.call_back,
queue='queue_consumer2',
no_ack=False,
consumer_tag=str(uuid.uuid4())
) def consume(self):
self.receive_msg()
self.channel.start_consuming() if __name__ == '__main__':
rabbit_consumer = RabbitConsumer()
rabbit_consumer.consume()
fanout会将接受到的所有消息广播到消费者consumer1和消费者consumer2，交换机的缺陷：它只能无意识的播放，不够灵活地控制消息广播给指定的消费者
2. direct(直连交换机)
对于direct，根据绑定键判定应该将数据发送至哪个队列，消息进入队列，其绑定秘钥（routing_key）与消息的路由秘钥要完全匹配，当exchange使用相同的绑定秘钥（routing_key）去绑定多个队列也是合法的，在这种情况下direct exchange的效果等同于fanout exchange，交换机会将消息广播到所有匹配的队列当中。 direct生产者：
import pika class RabbitProducer(object):
"""
与RabbitMq服务器建立连接
""" def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 声明一个exchange交换机,交换机的类型为direct
self.channel.exchange_declare(
exchange='direct_exchange', exchange_type='direct', durable=True
) def send_msg(self, routing_key, message):
"""
:param routing_key: 消息的路由键 本例中为routing_info
:param message: 生成者发送的消息
:return:
"""
self.channel.basic_publish(
exchange='direct_exchange',
routing_key=routing_key,
body=message,
properties=pika.BasicProperties(
delivery_mode=2,
# 消息进行持久化(防止服务器挂掉.)===> 如果没有queue绑定到这个exchange交换机,这个参数是没有的.
)) def close(self):
self.conn.close() if __name__ == "__main__":
rabbit_producer = RabbitProducer()
routing_key = 'routing_info'
for i in range(10):
message = 'hello world {}!'.format(i)
print('生产者发送的消息为:{}'.format(message))
rabbit_producer.send_msg(routing_key, message)
direct消费者：
import pika
import uuid class RabbitConsumer(object):
"""
消费者(订阅者)
""" def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 消息持久化
self.channel.queue_declare(
exclusive=False, durable=True, queue='task_queue'
) # 交换机类型为direct.
self.channel.exchange_declare(
exchange='direct_exchange', exchange_type='direct', durable=True
) # 将队列与该exchange交换机进行绑定
routing_keys = ['routing_info', 'aaa']
for routing_key in routing_keys:
self.channel.queue_bind(
exchange='direct_exchange', queue='task_queue', routing_key=routing_key
) # 如果生产者发生消息的routing_key与消费者绑定队列的routing_key相同则成功发送 def call_back(self, channel, method, properties, body):
"""
消费者对消息进行确认,防止消费者挂掉
:param channel:
:param method:
:param properties:
:param body:
:return:
"""
self.channel.basic_ack(delivery_tag=method.delivery_tag)
print('接收到的消息为:{}'.format(str(body))) def receive_msg(self):
print('开始接受消息...')
self.channel.basic_qos(prefetch_count=1) # TODO 告诉RabbitMQ,不要向我发送新的消息.
self.channel.basic_consume(
consumer_callback=self.call_back,
queue='task_queue',
no_ack=False,
consumer_tag=str(uuid.uuid4())
) def consume(self):
self.receive_msg()
self.channel.start_consuming() if __name__ == '__main__':
rabbit_consumer = RabbitConsumer()
rabbit_consumer.consume()
direct直连交换机相当于是fanout的升级版，当消费者的队列绑定的秘钥routing_key与生产者的routing_key相同时，消费者就会收到消息；当所有消费者的队列所绑定的routing_key都一样且与生产者相同时，就相当于fanout交换机
3. topic(话题交换机)
direct(直连交换机)虽然相当于fanout的升级版，但它仍然有局限性，它不能根据多个标准进行路由;topic(话题交换机)可以很好地解决这一问题：
(1) 如果消息的路由秘钥与队列的绑定秘钥符合匹配规则，topic就会将消息发送到相应的队列当中
(2) 对于绑定键(routing_key)有两个特殊的情况： * （星号）可以代替一个单词，＃（散列）可以替代零个或多个单词
(3) 对于发送到topic交换机消息的routing_key如果包含特殊字符，只能是由"."分割的单词表，如("zhangsan.lisi")
topic 生产者：
import pika class RabbitProducer(object):
def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 声明交换机,交换机的类型为topic
self.channel.exchange_declare(
exchange='logs_topic', exchange_type='topic', durable=True
) def send_msg(self, routing_key, message):
"""
:param routing_key: 消息的路由键
:param message: 生成者发送的消息
:return:
"""
self.channel.basic_publish(
exchange='logs_topic',
routing_key=routing_key,
body=message,
properties=pika.BasicProperties(
delivery_mode=2,
# 消息进行持久化
)) def close(self):
self.conn.close() if __name__ == "__main__":
rabbit_producer = RabbitProducer()
routing_keys = ['info', "debug", "a.debug.b", "a.info.b"]
for routing_key in routing_keys:
message = 'hello world! {}'.format(routing_key)
print('生产者发送的消息为:{}'.format(message))
rabbit_producer.send_msg(routing_key, message)
topic 消费者1 --> 实现fanout交换机：
"""
当topic交换机使用#绑定键绑定队列时，此时topic交换机就会将消息广播到所有的队列当中，
不管消息的路由秘钥如何，此时topic交换机的效果等同于fanout:发送所有消息都会接受到
"""
import pika
import uuid class RabbitConsumer(object):
def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 消息持久化
self.channel.queue_declare(
exclusive=False, durable=True, queue='task_queue'
) # 声明交换机,其类型为topic
self.channel.exchange_declare(
exchange='logs_topic', exchange_type='topic', durable=True
) # 将队列与该交换机进行绑定
routing_keys = ['#'] # 使用#绑定键时,它将接受所有的消息,同fanout效果一样.
for routing_key in routing_keys:
self.channel.queue_bind(
exchange='logs_topic', queue='task_queue', routing_key=routing_key
) def call_back(self, channel, method, properties, body):
"""
消费者对消息进行确认,防止消费者挂掉
:param channel:
:param method:
:param properties:
:param body:
:return:
"""
self.channel.basic_ack(delivery_tag=method.delivery_tag)
print('接收到的消息为:{}'.format(str(body))) def receive_msg(self):
print('开始接受消息...')
self.channel.basic_qos(prefetch_count=1)
self.channel.basic_consume(
consumer_callback=self.call_back,
queue='task_queue',
no_ack=False, # 消费者对消息进行确认
consumer_tag=str(uuid.uuid4())
) def consume(self):
self.receive_msg()
self.channel.start_consuming() if __name__ == '__main__':
rabbit_consumer = RabbitConsumer()
rabbit_consumer.consume()
topic 消费者2 --> 实现direct交换机：
"""
当topic交换机没有使用*和#匹配符绑定键绑定队列时，此时topic交换机的效果等同于direct，
会收到key相匹配的消息 如：info debug
"""
import pika
import uuid class RabbitConsumer(object):
def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 消息持久化
self.channel.queue_declare(
exclusive=False, durable=True, queue='work_queue'
) #
# 声明交换机,其类型为topic
self.channel.exchange_declare(
exchange='logs_topic', exchange_type='topic', durable=True
) # 将队列与交换机进行绑定
routing_keys = ['info', 'debug']
for routing_key in routing_keys:
self.channel.queue_bind(
exchange='logs_topic', queue='work_queue', routing_key=routing_key
) def call_back(self, channel, method, properties, body):
"""
消费者对消息进行确认,防止消费者挂掉
:param channel:
:param method:
:param properties:
:param body:
:return:
"""
self.channel.basic_ack(delivery_tag=method.delivery_tag)
print('接收到的消息为:{}'.format(str(body))) def receive_msg(self):
print('开始接受消息...')
self.channel.basic_qos(prefetch_count=1)
self.channel.basic_consume(
consumer_callback=self.call_back,
queue='work_queue',
no_ack=False, # 消费者对消息进行确认
consumer_tag=str(uuid.uuid4())
) def consume(self):
self.receive_msg()
self.channel.start_consuming() if __name__ == '__main__':
rabbit_consumer = RabbitConsumer()
rabbit_consumer.consume()
topic 消费者3 --> 实现*.x.* 消息匹配：
"""
匹配任意点分割的单词 生产者发送的：a.debug.b 则匹配了'*.debug.*'
生产者发送的：a.info.b 则匹配了'*.info.*'
"""
import pika
import uuid class RabbitConsumer(object):
def __init__(self):
self.conn = pika.BlockingConnection(
pika.ConnectionParameters(host='localhost', port=5672)
)
self.channel = self.conn.channel() # 消息持久化
self.channel.queue_declare(
exclusive=False, durable=True, queue='other_queue'
) # 声明交换机,其类型为topic
self.channel.exchange_declare(
exchange='logs_topic', exchange_type='topic', durable=True
) # 将队列与交换机进行绑定
routing_keys = ['*.info.*', '*.debug.*', 'dfdf*']
for routing_key in routing_keys:
self.channel.queue_bind(
exchange='logs_topic', queue='other_queue', routing_key=routing_key
) def call_back(self, channel, method, properties, body):
"""
消费者对消息进行确认,防止消费者挂掉
:param channel:
:param method:
:param properties:
:param body:
:return:
"""
self.channel.basic_ack(delivery_tag=method.delivery_tag)
print('接收到的消息为:{}'.format(str(body))) def receive_msg(self):
print('开始接受消息...')
self.channel.basic_qos(prefetch_count=1)
self.channel.basic_consume(
consumer_callback=self.call_back,
queue='other_queue',
no_ack=False, # 消费者对消息进行确认
consumer_tag=str(uuid.uuid4())
) def consume(self):
self.receive_msg()
self.channel.start_consuming() if __name__ == '__main__':
rabbit_consumer = RabbitConsumer()
rabbit_consumer.consume()
topic消费者执行结果：
消费者1：
消费者2：
消费者3：