应用Python 实现MQTT Client

#coding:utf-8

#!/usr/bin/python3

import json

import os

import binascii

import asn1tools

import sys

import paho.mqtt.client as mqtt

import requests

import logging

from enum import Enum

from queue import Queue

 

__all__ = ["MQTTClient"]

 

class MQTTClient:

 

    def __init__(self,host, port, qos, timeout, log):

        self.host = host

        self.port = port

        self.qos = qos

        self.queue = Queue()

        self.mqtt_client = None

        self.timeout = timeout

        self.log = log

 

    def on_message(self, client, userdata, msg):

        self.log.debug('get a message: %s' % msg)

        self.queue.put(msg)

 

    def subscribe(self, topic):

        self.mqtt_client.subscribe(topic, self.qos)

        self.log.debug('subscribe to %s' % topic)

 

    def unsubscribe(self, topic):

        self.mqtt_client.unsubscribe(topic)

        self.log.debug('unsubscribe %s' % topic)

 

    def receive_msg(self, timeout=None):

        self.log.debug('waiting for message.')

        if timeout is None:

        timeout = self.timeout

        return self.queue.get(timeout=timeout)

 

    def publish(self, topic, blob):

        self.mqtt_client.publish(topic, blob)

 

    def loop_start(self):

        if self.mqtt_client is None:

        self.mqtt_client = mqtt.Client()

        self.mqtt_client.on_message = self.on_message

        self.mqtt_client.connect(self.host, self.port, self.timeout)

        self.mqtt_client.loop_start()

 

    def loop_stop(self):

        if self.mqtt_client is not None:

        self.mqtt_client.loop_stop()

        self.mqtt_client.disconnect()

        self.mqtt_client = None