sensecap/src/base/BaseMqtt.js

## Install ``` npm install sensecap --save ```

var logger = require('../utils/loggerUtil')
var mqtt = require('mqtt')

function BaseMqtt(options) {
    // 连接选项
    this.option = {
        clean: true,
        keepalive: 30,
        connectTimeout: 4000, // 超时时间
        protocol: 'mqtt',
        port: 1883,
        password: options.accessKeySecret,
        reconnectPeriod: 10000,
        transformWsUrl: function (url, options, client) {
            logger.log('transformWsUrl: ' + url);
            return url;
        }
    }
    this.orgId = '0'
    this.isConnected = false;

    switch (options.region) {
        case 1:
            this.brokerUrl = 'http://sensecap-openstream.seeed.cn';
            break;
        case 2:
            this.brokerUrl = 'http://sensecap-openstream.seeed.cc';
            break;
        default:
            this.brokerUrl = 'http://sensecap-openstream.seeed.cn';
            break;
    }
}

BaseMqtt.prototype = {
    connect: function (callback) {
        var that = this;
        this.option.clientId = 'org-' + this.orgId + '-nodejs';
        this.option.username = 'org-' + this.orgId;
        if (this.isConnected) {
            callback(null);
        } else {
            this.client  = mqtt.connect(this.brokerUrl, this.option);
        }

        this.client.on('connect', function () {
            logger.log('mqtt connect success!');
            that.isConnected = true;
            callback(null)
        });

        this.client.on('message', function (topic, message) {
            // logger.log('mqtt message===>');
            // logger.log(topic);
            // logger.log(message.toString());
            if (that.onMessageCallback) {
                that.onMessageCallback(null, topic, message.toString());
            }
        });

        this.client.on('error', function (error) {
            logger.log('mqtt connect fail!');
            logger.error(error);
            that.isConnected = false;
            callback(error)
        });

        this.client.on('reconnect', function () {
            logger.log('mqtt reconnect!');
        });

        this.client.on('offline', function () {
            logger.log('mqtt offline!');
            that.isConnected = false;
        });

        this.client.on('end', function () {
            logger.log('mqtt end!');
            that.isConnected = false;
        });

        this.client.on('close', function () {
            logger.log('mqtt close!');
            that.isConnected = false;
        });
    },
    subscribeData: function (deviceEui, channel, measurementId, callback) {
        var topic = '/device_sensor_data/' + this.orgId + '/' + (deviceEui ? deviceEui : '+') + '/' + (channel ? channel : '+') + '/+/' + (measurementId ? measurementId : '+')
        logger.log('subscribe topic========: ' + topic)
        this.onMessageCallback = callback;

        this.client.subscribe(topic, {
            qos: 2,
            // 0 = 订阅建立时发送保留消息 1 = 订阅建立时，若该订阅当前不存在则发送保留消息 2 = 订阅建立时不要发送保留消息
            rh: 2,
        }, function (err) {
            if (!err) {
                logger.log('mqtt subscribe success: ' + topic);
            } else {
                callback(err);
            }
        })
    },
    unSubscribe: function (deviceEui, channel, measurementId, callback) {
        var topic = '/device_sensor_data/' + this.orgId + '/' + (deviceEui ? deviceEui : '+') + '/' + (channel ? channel : '+') + '/+/' + (measurementId ? measurementId : '+')
        this.client.unsubscribe(topic, {}, function (err) {
            if (!err) {
                logger.log('unsubscribe success: ' + topic);
                callback(null, topic);
            } else {
                logger.log('err========');
                logger.error(err);
                callback(err);
            }
        })
    },
    disconnect: function () {
        this.client.end(false, {
            reasonCode: 0 // 0:正常断开
        }, function () {
            logger.log('mqtt disconnect success!');
        })
    },
    setOrgId: function (orgId) {
        this.orgId = orgId
    },
    getOrgId: function () {
        return this.orgId;
    },
};

module.exports = BaseMqtt;