前言

經歷過各種問題的磨難終於基本搭建完成了自己的MQTT伺服器,接下來我就趕緊寫個Python程式測試下.

安裝

這裡採用paho.mqtt.python編寫程式,詳情參閱這裡
開啟powershell,執行pip install paho-mqtt安裝模組

程式

# coding=utf-8
import json
import threading

import paho.mqtt.client as mqtt

# 當連線上伺服器後回撥此函式
import time

from my_lib.code_handle.code_handle import auto_code
from
 
 windows_info.read_info import Win_psutil


class MqttClient:
    client = mqtt.Client('tester')

    def __init__(self, host, port):
        self._host = host
        self._port = port
        self.client.on_connect = self._on_connect  # 設定連線上伺服器回撥函式
        self.client.on_message = self._on_message  # 設定接收到伺服器訊息回撥函式
 


    def connect(self, username='tester', password='tester'):
        self.client.username_pw_set(username, password)
        self.client.connect(self._host, self._port, 60)  # 連線伺服器,埠為1883,維持心跳為60秒

    def publish(self, topic, data):
        self.client.publish(topic, data)

    def loop(self, timeout=None)
 
:
        thread = threading.Thread(target=self._loop, args=(timeout,))
        # thread.setDaemon(True)
        thread.start()

    def _loop(self, timeout=None):
        if not timeout:
            self.client.loop_forever()
        else:
            self.client.loop(timeout)

    def _on_connect(self, client, userdata, flags, rc):
        print("\nConnected with result code " + str(rc))
        client.subscribe("test-0")

    def _on_message(self, client, userdata, msg):  # 從伺服器接受到訊息後回撥此函式
        print "\n主題:" + auto_code(str(msg.topic)) + " 訊息:" + auto_code(str(msg.payload))

    def _is_json(self, data):
        try:
            json.loads(data)
        except ValueError:
            return False
        return True

    def publish_loop(self):
        pass


if __name__ == '__main__':
    host=None
    client = MqttClient(host, 1883)
    client.connect('tester','tester')
    client.publish('test-0', '我上線啦!')
    client.loop()
    wp = Win_psutil()#自己定義的一個類
    while True:
        data_json=wp.auto_json()#方法返回一個包含CPU和程序資訊的JSON字串
        client.publish('test-0',data_json)
        time.sleep(2)

這裡自己封裝了類,主要功能是連上伺服器訂閱預設主題,接收到訊息即打印出來.
在主程式中先例項化類,接著使用預設使用者名稱與密碼登陸,在主題”test-0上”釋出資訊,接著定時將打包成JSON資訊的資料釋出到”test-0”這個主題