MQTT - broker - 本地安装启动moquette

一、MQTT简介

MQTT（Message Queuing Telemetry Transport，消息队列遥测传输）是一个基于客户端-服务端的消息发布/订阅传输协议。它是一种基于发布/订阅（publish/subscribe）模式的"轻量级"构建于TCP/IP协议上的通讯协议，该协议构建于TCP/IP协议上。MQTT最大优点在于，可以以极少的代码和有限的带宽，为连接远程设备提供实时可靠的消息服务。作为一种低开销、低带宽占用的即时通讯协议，其在物联网、小型设备、移动应用等方面有着较广泛的应用。

二、MQTT Broker

broker的主要职责是接受发布者发布的所有消息，并将其过滤后分发给不同的消息订阅者。

MQTT支持众多broker实现方式，具体参见MQTT官网说明：https://mqtt.org/software/，broker对比参见https://www.jianshu.com/p/cf91f4bea071,为方便阅读，从文档摘图如下：(若有侵权请作者联系我删除)：

本文主要介绍 moquette 的本地安装启动方式；

三、Moquette

3.1 源码地址

      本文样例代码地址；https://github.com/andsel/moquette 

      其他git的地址参见: https://github.com/milliondreams/moquette-mqtt 

3.2 代码架构

3.3 本地启动broker

将项目代码导入开发工具(本文使用idea工具)，服务启动类代码参见：io.moquette.broker.Server

代码如下：

/*
 * Copyright (c) 2012-2018 The original author or authors
 * ------------------------------------------------------
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Apache License v2.0 which accompanies this distribution.
 *
 * The Eclipse Public License is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * The Apache License v2.0 is available at
 * http://www.opensource.org/licenses/apache2.0.php
 *
 * You may elect to redistribute this code under either of these licenses.
 */
package io.moquette.broker;

import io.moquette.BrokerConstants;
import io.moquette.broker.config.*;
import io.moquette.interception.InterceptHandler;
import io.moquette.persistence.H2Builder;
import io.moquette.persistence.MemorySubscriptionsRepository;
import io.moquette.interception.BrokerInterceptor;
import io.moquette.broker.security.*;
import io.moquette.broker.subscriptions.CTrieSubscriptionDirectory;
import io.moquette.broker.subscriptions.ISubscriptionsDirectory;
import io.moquette.broker.security.IAuthenticator;
import io.moquette.broker.security.IAuthorizatorPolicy;
import io.netty.handler.codec.mqtt.MqttPublishMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.text.ParseException;
import java.util.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;

import static io.moquette.logging.LoggingUtils.getInterceptorIds;

public class Server {

    private static final Logger LOG = LoggerFactory.getLogger(io.moquette.broker.Server.class);

    private ScheduledExecutorService scheduler;
    private NewNettyAcceptor acceptor;
    private volatile boolean initialized;
    private PostOffice dispatcher;
    private BrokerInterceptor interceptor;
    private H2Builder h2Builder;
    private SessionRegistry sessions;

    public static void main(String[] args) throws IOException {
        final Server server = new Server();
        server.startServer();
        System.out.println("Server started, version 0.13-SNAPSHOT");
        //Bind a shutdown hook
        Runtime.getRuntime().addShutdownHook(new Thread(server::stopServer));
    }

    /**
     * Starts Moquette bringing the configuration from the file located at m_config/moquette.conf
     *
     * @throws IOException in case of any IO error.
     */
    public void startServer() throws IOException {
        File defaultConfigurationFile = defaultConfigFile();
        LOG.info("Starting Moquette integration. Configuration file path={}", defaultConfigurationFile.getAbsolutePath());
        IResourceLoader filesystemLoader = new FileResourceLoader(defaultConfigurationFile);
        final IConfig config = new ResourceLoaderConfig(filesystemLoader);
        startServer(config);
    }

    private static File defaultConfigFile() {
        String configPath = System.getProperty("moquette.path", null);
        return new File(configPath, IConfig.DEFAULT_CONFIG);
    }

    /**
     * Starts Moquette bringing the configuration from the given file
     *
     * @param configFile text file that contains the configuration.
     * @throws IOException in case of any IO Error.
     */
    public void startServer(File configFile) throws IOException {
        LOG.info("Starting Moquette integration. Configuration file path: {}", configFile.getAbsolutePath());
        IResourceLoader filesystemLoader = new FileResourceLoader(configFile);
        final IConfig config = new ResourceLoaderConfig(filesystemLoader);
        startServer(config);
    }

    /**
     * Starts the integration with the given properties.
     * <p>
     * Its suggested to at least have the following properties:
     * <ul>
     *  <li>port</li>
     *  <li>password_file</li>
     * </ul>
     *
     * @param configProps the properties map to use as configuration.
     * @throws IOException in case of any IO Error.
     */
    public void startServer(Properties configProps) throws IOException {
        LOG.debug("Starting Moquette integration using properties object");
        final IConfig config = new MemoryConfig(configProps);
        startServer(config);
    }

    /**
     * Starts Moquette bringing the configuration files from the given Config implementation.
     *
     * @param config the configuration to use to start the broker.
     * @throws IOException in case of any IO Error.
     */
    public void startServer(IConfig config) throws IOException {
        LOG.debug("Starting Moquette integration using IConfig instance");
        startServer(config, null);
    }

    /**
     * Starts Moquette with config provided by an implementation of IConfig class and with the set
     * of InterceptHandler.
     *
     * @param config   the configuration to use to start the broker.
     * @param handlers the handlers to install in the broker.
     * @throws IOException in case of any IO Error.
     */
    public void startServer(IConfig config, List<? extends InterceptHandler> handlers) throws IOException {
        LOG.debug("Starting moquette integration using IConfig instance and intercept handlers");
        startServer(config, handlers, null, null, null);
    }
	
	... ...
}

为方便阅读，此处仅摘取部分代码显示，若有其他需要，请自行下载全部代码查阅；

扫描二维码关注公众号，回复： 15813837 查看本文章

阅读代码可知，启动服务需依赖读取moquette配置文件：

默认读取的为 IConfig.DEFAULT_CONFIG 配置的 "config/moquette.conf"，即 moquette.path 配置指向代码 config 上级目录即可；

moquette.path 本地配置方式如下：

配置完成后右键 RUN Server.main()，查看启动日志：

至此 moquette 本地服务启动成功；

四 订阅发布demo

基于 MQTT-Client实现，参见：MQTT - 订阅发布demo