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));
}