MQTT 3.1.1协议:
https://www.runoob.com/manual/mqtt/protocol/MQTT-3.1.1-CN.pdf
一、python客户端
1.环境安装
（1）python版本
（2）pip版本
pip更新：
python -m pip install --upgrade pip -i easy_install -U pip
（3）安装mqtt包
pip install -i https://pypi.doubanio.com/simple paho-mqtt
2.消息发布
import random
import time
from paho.mqtt import client as mqtt_client
#broker = 'broker.emqx.io'
broker = 'broker-cn.emqx.io'
port = 1883
topic = "/python/mqtt"
# generate client ID with pub prefix randomly
client_id = f'python-mqtt-{random.randint(0, 1000)}'
def connect_mqtt():
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to MQTT Broker!")
else:
print("Failed to connect, return code %d\n", rc)
client = mqtt_client.Client(client_id)
client.on_connect = on_connect
client.connect(broker, port)
return client
def publish(client):
msg_count = 0
while True:
time.sleep(1)
msg = f"messages: {msg_count}"
result = client.publish(topic, msg)
# result: [0, 1]
status = result[0]
if status == 0:
print(f"Send `{msg}` to topic `{topic}`")
else:
print(f"Failed to send message to topic {topic}")
msg_count += 1
def run():
client = connect_mqtt()
client.loop_start()
publish(client)
if __name__ == '__main__':
run()3.消息订阅
import random
from paho.mqtt import client as mqtt_client
#broker = 'broker.emqx.io'
broker = 'broker-cn.emqx.io'
port = 1883
topic = "/python/mqtt"
# generate client ID with pub prefix randomly
client_id = f'python-mqtt-{random.randint(0, 100)}'
def connect_mqtt() -> mqtt_client:
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to MQTT Broker!")
else:
print("Failed to connect, return code %d\n", rc)
client = mqtt_client.Client(client_id)
client.on_connect = on_connect
client.connect(broker, port)
return client
def subscribe(client: mqtt_client):
def on_message(client, userdata, msg):
print(f"Received `{msg.payload.decode()}` from `{msg.topic}` topic")
client.subscribe(topic)
client.on_message = on_message
def run():
client = connect_mqtt()
subscribe(client)
client.loop_forever()
if __name__ == '__main__':
run()4.免费mqtt服务器(Broker)
链接：https://www.emqx.com/zh/mqtt/public-mqtt5-broker
二、测试
1.消息发布运行
2.消息订阅运行
