• 基于mqtt的消息推送(二)服务端实现


    基于Mosca的服务端实现

    Mosca简介,Mosca基于node.js开发,特性引用自项目首页介绍如下:

    Features

    • MQTT 3.1 and 3.1.1 compliant.
    • QoS 0 and QoS 1.
    • Various storage options for QoS 1 offline packets, and subscriptions.
    • As fast as it is possible.
    • Usable inside ANY other Node.js app.
    • Supports Node.js v0.10 and v0.12.
    • Supports io.js v1.x and v2.x and v3.x (please do not use v3.1.0)

    需要特别说明的是Mosca并不支持Qos 2。

    为什么选择Mosca?首先基于node.js开发,上手难度相对较小,其次协议支持完整,除了不支持Qos 2,其它的基本都支持。持久化支持redis以及mongo。二次开发接口简单。部署非常简单,并且支持docker镜像。

    开发步骤

    安装Mosca

    本文环境假设你已经安装了node.js环境以及redis,我本机的环境如下:mac ox 10.11.2 node.js v0.12 redis最新版本。

    Mosca项目托管地址:https://github.com/mcollina/mosca
    官方wiki:https://github.com/mcollina/mosca/wiki

    安装非常简单,源引自官方说明如下:

    Standalone

    1
    2
    npm install mosca bunyan -g
    mosca -v | bunyan

    Embedded

    1
    npm install mosca --save

    启动脚本

    官方给了一个简单的例子,如下是我现在使用的测试代码:

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    var mosca = require('mosca')

    //ascoltatore是Mosca作者开发的一个订阅与发布类库,Mosca核心的订阅与发布模型
    var ascoltatore = {
    type: 'redis', //指定类型,mongo的写法请参考官方wiki
    redis: require('redis'),
    db: 1,
    port: 6379,
    return_buffers: true, // to handle binary payloads
    //指定数据保留多长时间,单位毫秒
    ttl: {
    // TTL for subscriptions is 23 hour
    subscriptions: 23 * 60 * 60 * 1000,
    // TTL for packets is 23 hour
    packets: 23 * 60 * 60 * 1000,
    },
    host: "localhost"
    };

    //基本参数设置
    var moscaSettings = {
    port: 1883, //设置监听端口
    backend: ascoltatore,
    maxInflightMessages: 10240, //设置单条消息的最大长度,超出后服务端会返回
    //设置WebSocket参数
    http: {
    port: 1884,
    bundle: true,
    static: './'
    },
    //数据持久化参数设置
    persistence: {
    factory: mosca.persistence.Redis,
    db: 1,
    port: 6379,
    return_buffers: true, // to handle binary payloads
    ttl: {
    // TTL for subscriptions is 23 hour
    subscriptions: 23 * 60 * 60 * 1000,
    // TTL for packets is 23 hour
    packets: 23 * 60 * 60 * 1000,
    },
    host: "localhost"
    }
    };

    //如果需要用户登录验证权限,需要改写此方法
    //这里以简单判断了用户名和密码为例,真实环境可以连接实际业务系统的鉴权服务
    var authenticate = function(client, username, password, callback) {
    var authorized = (username === 'test' && password.toString() === 'passwd');
    if (authorized) client.user = username;
    callback(null, authorized);
    }

    function authPub(client, topic, payload, callback) {
    callback(null, payload);
    }

    function authSub(client, topic, callback) {
    callback(null, topic);
    }

    var server = new mosca.Server(moscaSettings);
    server.on('ready', setup);

    server.on('clientConnected', function(client) {
    console.log('client connected', client.id);
    });

    server.on('published', function(packet, client) {
    console.log('Published', packet.topic + packet.payload);
    });

    // fired when the mqtt server is ready
    function setup() {
    server.authenticate = authenticate;
    server.authorizePublish = authPub;
    server.authorizeSubscribe = authSub;

    console.log('Mosca server is up and running')
    }

    二次开发

    可以监听的事件列表

    • clientConnected : when a client is connected; the client is passed as a
      parameter.
    • clientDisconnecting : when a client is being disconnected; the client is
      passed as a parameter.
    • clientDisconnected : when a client is disconnected; the client is passed as
      a parameter.
    • published : when a new message is published; the packet and the client are
      passed as parameters.
    • delivered : when a client has sent back a puback for a published message; the packet and the client are
      passed as parameters.
    • subscribed : when a client is subscribed to a topic; the topic and the
      client are passed as parameters.
    • unsubscribed : when a client is unsubscribed to a topic; the topic and the
      client are passed as parameters.

    有了上面可以监听到事件你就可以根据自己的业务进行相应的开发,拦截特定的事件并添加业务代码

    ascoltatore托管地址 https://github.com/mcollina/ascoltatori

    高级参数设置可以参考 https://github.com/mcollina/mosca/wiki/Mosca-advanced-usage

    权限验证可以参考 https://github.com/mcollina/mosca/wiki/Authentication-&-Authorization

    配置ssl可以参考 https://github.com/mcollina/mosca/wiki/TLS-SSL-Configuration

    配置WebSocket可以参考 https://github.com/mcollina/mosca/wiki/MQTT-over-Websockets

    写在最后

    感谢Mosca的作者mcollina,Mosca非常强大,并且足够简单。下篇文章会介绍如何利用IOS和Android开源客户端类库与Mosca对接,敬请期待!


    转载: http://targe.me/2015/12/29/mqtt-second/

  • 相关阅读:
    jquery新知识
    jquery回顾
    Filter和Listener
    jsp,jstl,el
    cookie和session
    servlet和HTTP原理
    xml基本知识
    linux 相关操作
    linux mysql 相关操作、问题
    linux 文件结构
  • 原文地址:https://www.cnblogs.com/youyong/p/11388384.html
Copyright © 2020-2023  润新知