代码实现一个线程与mqtt服务器联系

以下是使用Python paho-mqtt库实现线程与MQTT服务器联系的代码示例：

import threading
import paho.mqtt.client as mqtt

# MQTT服务器地址和端口号
MQTT_SERVER = "localhost"
MQTT_PORT = 1883

# MQTT订阅主题
MQTT_TOPIC = "/test"

# 线程类
class MyThread(threading.Thread):
    def __init__(self, thread_id, name, client):
        threading.Thread.__init__(self)
        self.thread_id = thread_id
        self.name = name
        self.client = client

    def run(self):
        print(f"Starting {self.name}")
        # 发布消息
        self.client.publish(MQTT_TOPIC, f"Hello from {self.name}")
        print(f"Exiting {self.name}")

# MQTT连接回调函数
def on_connect(client, userdata, flags, rc):
    print(f"Connected with result code {rc}")
    # 订阅主题
    client.subscribe(MQTT_TOPIC)

# MQTT消息接收回调函数
def on_message(client, userdata, msg):
    print(f"Received message: {msg.payload.decode('utf-8')}")

if __name__ == "__main__":
    # 创建MQTT客户端实例
    client = mqtt.Client()

    # 设置连接回调函数和消息接收回调函数
    client.on_connect = on_connect
    client.on_message = on_message

    # 连接MQTT服务器
    client.connect(MQTT_SERVER, MQTT_PORT, 60)

    # 启动线程
    thread1 = MyThread(1, "Thread-1", client)
    thread2 = MyThread(2, "Thread-2", client)
    thread1.start()
    thread2.start()

这个示例中，我们创建了一个MyThread线程类，并在run方法中实现了向MQTT服务器发布消息的逻辑。在主程序中，我们创建了两个线程，分别启动这两个线程。在连接MQTT服务器后，我们订阅了一个主题，当收到该主题的消息时，会触发on_message回调函数。