我正在使用mqtt包在 NodeJS 中编写一个 MQTT 订阅者。这个订阅者的目标是接收到任何/所有主题的所有消息，但看起来订阅#（订阅所有主题）似乎不起作用。但是当我#用一个实际的主题名称替换它似乎工作正常。不知道为什么它不工作。
PS：我使用的broker是emqx。
这是下面的代码。
const mqtt = require('mqtt');
const TOPIC = '#';
const HOST = process.env.HOST || 'localhost';
const PORT = process.env.PORT || 1883;
const USERNAME = process.env.USERNAME || 'username';
const PASSWORD = process.env.PASSWORD || 'password';
const PROTOCOL = 'mqtt';
const clientOption = {
port: PORT,
host: HOST,
username: USERNAME,
password: PASSWORD,
protocol: PROTOCOL
};
const client = mqtt.connect(clientOption);
console.log(`Connecting to mqtt://${HOST}:${PORT}@${USERNAME} topic:${TOPIC} ...`);
client.on('connect', function () {
console.log(`Connected!`);
client.subscribe(TOPIC, function(err) {
if(err) {
console.error(err);
} else {
console.log(`Subscription to ${TOPIC} successful.`);
}
});
client.on('message', function (topic, message) {
// message is Buffer
console.log(`Incoming message to topic = ${topic} ...`);
console.log(message.toString());
console.log('Preparing outbound message');
const outboundMsg = {...message, source: topic}
console.log('Outbound message below');
console.log(outboundMsg);
});
});