Nacos - 启动提到了NacosWatch#start会获取NamingService，他托管NacosServiceManager来实现这件事。

NacosServiceManager#getNamingService

为空的时候，去创立一个NamingService

public NamingService getNamingService(Properties properties) {    // 为空的时候，去创立一个NamingService    if (Objects.isNull(this.namingService)) {        buildNamingService(properties);    }    // 返回namingService    return namingService;}

NacosServiceManager#buildNamingService

加锁保障只能有一个namingService

private NamingService buildNamingService(Properties properties) {    if (Objects.isNull(namingService)) {        // 加锁保障只能有一个namingService        synchronized (NacosServiceManager.class) {            if (Objects.isNull(namingService)) {                namingService = createNewNamingService(properties);            }        }    }    return namingService;}

最终调用NamingFactory#createNamingService来创立NamingService对象。

private NamingService createNewNamingService(Properties properties) {    try {        return createNamingService(properties);    }    catch (NacosException e) {        throw new RuntimeException(e);    }}// NacosFactory中的办法public static NamingService createNamingService(Properties properties) throws NacosException {    return NamingFactory.createNamingService(properties);}

NamingFactory#createNamingService

通过反射的形式创立了com.alibaba.nacos.client.naming.NacosNamingService对象。

public static NamingService createNamingService(String serverList) throws NacosException {    try {        Class<?> driverImplClass = Class.forName("com.alibaba.nacos.client.naming.NacosNamingService");        Constructor constructor = driverImplClass.getConstructor(String.class);        NamingService vendorImpl = (NamingService) constructor.newInstance(serverList);        return vendorImpl;    } catch (Throwable e) {        throw new NacosException(NacosException.CLIENT_INVALID_PARAM, e);    }}

NacosNamingService#init

次要是初始化namespace、序列化、注册核心服务地址、WebRootContext上下文、缓存门路、日志名称、EventDispatcher、NamingProxy、BeatReactor、HostReactor。
EventDispatcher负责解决服务监听相干。
NamingProxy负责和Nacos服务的通信，比方服务注册、服务勾销注册、心跳等。
BeatReactor负责检测心跳。
HostReactor负责获取、更新并保留服务信息。

private void init(Properties properties) throws NacosException {    ValidatorUtils.checkInitParam(properties);    // namespace默认public    this.namespace = InitUtils.initNamespaceForNaming(properties);    // 序列化初始化    InitUtils.initSerialization();    // 注册核心服务地址初始化，这个从配置文件取    initServerAddr(properties);    //初始化WebRootContext上下文    InitUtils.initWebRootContext();    // 初始化缓存门路 System.getProperty("user.home") + "/nacos/naming/" + namespace    initCacheDir();    // 初始化日志名称naming.log    initLogName(properties);    // 初始化EventDispatcher    this.eventDispatcher = new EventDispatcher();    // 初始化NamingProxy    this.serverProxy = new NamingProxy(this.namespace, this.endpoint, this.serverList, properties);    // 初始化BeatReactor    this.beatReactor = new BeatReactor(this.serverProxy, initClientBeatThreadCount(properties));    // 初始化HostReactor    this.hostReactor = new HostReactor(this.eventDispatcher, this.serverProxy, beatReactor, this.cacheDir,            isLoadCacheAtStart(properties), initPollingThreadCount(properties));}