大家好，又见面了，我是你们的朋友全栈君。
就让我来试试传说中最适用于IOT的MQTT协议。
安装
虽然搜索资料很多，但大多是MQTT的使用，尽管有搭建服务器的文章，但我感觉写的不太清楚，大多数文章选择了Mosquitto(也许是Eclipse大厂出品的原因)。
经过寻找，找到了Nodejs写的mosca，但在Pi上老是安装失败，翻了翻Issues，找到了同作者写的依赖性小，轻量化的aedes。npm install aedes –save//最小例子
var aedes = require(‘aedes’)();
var server = require(‘net’).createServer(aedes.handle);
server.listen(8266);
简单使用
将所有的订阅与推送保存到sqlite3数据库中：//Nodejs
var aedes = require(‘aedes’)();
var colors = require(‘colors’);
var server = require(‘net’).createServer(aedes.handle);
var sqlite3 = require(‘sqlite3’).verbose();
var db = new sqlite3.Database(‘data.db’);
var port = 8266;
//更多事件查看Github：https://github.com/mcollina/aedes
aedes.on(‘publish’,function(packet,client) {
if (client) {
console.log(‘[ Publish ] CilentID:’.green,client.id,’ Qos:’.green,packet.qos,’ Data:[ ‘.green,String(packet.payload),’ ]’.green);
db.run(“INSERT INTO publish (date,client_id,topic,data) VALUES (datetime(‘now’),?,?,?);”,[client.id,packet.topic,String(packet.payload)]);
}
});
aedes.on(‘subscribe’, function (subscriptions, client) {
if (client) {
//subscriptions懒得历遍(一般情况同时只有一个吧)
db.run(“INSERT INTO subscribe (date,client_id,topic) VALUES (datetime(‘now’),?,?)”,[client.id,subscriptions[0].topic]);
console.log(‘[ Subscribe ] SubscripTions:’.green,subscriptions[0].topic,’ Qos:’.green,subscriptions[0].qos,’ CilentID:’.green,client.id);
}
});
aedes.on(‘unsubscribe’,function(unsubscriptions,client){
if(client){
//同理
console.log(‘[ unSubscribe ] unSubscripTions:’.green,unsubscriptions[0],’ CilentID:’.green,client.id);
db.run(“DELETE FROM subscribe WHERE client_id = ? AND topic = ?;”,[client.id,unsubscriptions[0]])
}
});
server.listen(port,function(){
console.log(‘[ Server ] server listening on port’.green,port)
});
//Sqlite3
CREATE TABLE “publish” ( `date` TEXT NOT NULL, `client_id` TEXT NOT NULL, `topic` TEXT NOT NULL, `data` TEXT NOT NULL );
CREATE TABLE “subscribe” ( `date` TEXT NOT NULL, `client_id` TEXT NOT NULL, `topic` TEXT NOT NULL );
//Micropython for ESP8266
>>> from umqtt.simple import MQTTClient
>>> conn = MQTTClient(‘esp8266′,’192.168.1.64’,8266)
>>> conn.connect()
0
>>> conn.publish(b’/test’,b’test’)
>>> conn.disconnect()
优缺点轻量化
可以更好的结合业务逻辑
不支持或不完全支持Qos2
发布者：全栈程序员-站长，转载请注明出处：https://javaforall.net/140313.html原文链接：https://javaforall.net
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