public <T> Exporter<T> export(Invoker<T> invoker) throws RpcException {URL url = invoker.getUrl();//获取url信息// export service.String key = serviceKey(url);//产生与发布的接口映射的key ,格式例如：com.alibaba.dubbo.demo.DemoService:20882DubboExporter<T> exporter = new DubboExporter<T>(invoker, key, exporterMap);//创建DubboExporter对象exporterMap.put(key, exporter);//缓存此对象//export an stub service for dispaching eventBoolean isStubSupportEvent = url.getParameter(Constants.STUB_EVENT_KEY,Constants.DEFAULT_STUB_EVENT);Boolean isCallbackservice = url.getParameter(Constants.IS_CALLBACK_SERVICE, false);if (isStubSupportEvent && !isCallbackservice){String stubServiceMethods = url.getParameter(Constants.STUB_EVENT_METHODS_KEY);if (stubServiceMethods == null || stubServiceMethods.length() == 0 ){if (logger.isWarnEnabled()){logger.warn(new IllegalStateException("consumer [" +url.getParameter(Constants.INTERFACE_KEY) +"], has set stubproxy support event ,but no stub methods founded."));}} else {stubServiceMethodsMap.put(url.getServiceKey(), stubServiceMethods);}}openServer(url);//打开服务return exporter;
}private void openServer(URL url) {// find server.String key = url.getAddress();//client 也可以暴露一个只有server可以调用的服务。boolean isServer = url.getParameter(Constants.IS_SERVER_KEY,true);if (isServer) {ExchangeServer server = serverMap.get(key);if (server == null) {serverMap.put(key, createServer(url));//创建新的服务} else {//server支持reset,配合override功能使用
            server.reset(url);}}
}private ExchangeServer createServer(URL url) {//默认开启server关闭时发送readonly事件url = url.addParameterIfAbsent(Constants.CHANNEL_READONLYEVENT_SENT_KEY, Boolean.TRUE.toString());//默认开启heartbeaturl = url.addParameterIfAbsent(Constants.HEARTBEAT_KEY, String.valueOf(Constants.DEFAULT_HEARTBEAT));String str = url.getParameter(Constants.SERVER_KEY, Constants.DEFAULT_REMOTING_SERVER);if (str != null && str.length() > 0 && ! ExtensionLoader.getExtensionLoader(Transporter.class).hasExtension(str))throw new RpcException("Unsupported server type: " + str + ", url: " + url);url = url.addParameter(Constants.CODEC_KEY, Version.isCompatibleVersion() ? COMPATIBLE_CODEC_NAME : DubboCodec.NAME);ExchangeServer server;try {server = Exchangers.bind(url, requestHandler);} catch (RemotingException e) {throw new RpcException("Fail to start server(url: " + url + ") " + e.getMessage(), e);}str = url.getParameter(Constants.CLIENT_KEY);if (str != null && str.length() > 0) {Set<String> supportedTypes = ExtensionLoader.getExtensionLoader(Transporter.class).getSupportedExtensions();if (!supportedTypes.contains(str)) {throw new RpcException("Unsupported client type: " + str);}}return server;

protected void doOpen() throws Throwable {NettyHelper.setNettyLoggerFactory();ExecutorService boss = Executors.newCachedThreadPool(new NamedThreadFactory("NettyServerBoss", true));//boss线程池ExecutorService worker = Executors.newCachedThreadPool(new NamedThreadFactory("NettyServerWorker", true));//工作线程池ChannelFactory channelFactory = new NioServerSocketChannelFactory(boss, worker, getUrl().getPositiveParameter(Constants.IO_THREADS_KEY, Constants.DEFAULT_IO_THREADS));bootstrap = new ServerBootstrap(channelFactory);//服务启动类final NettyHandler nettyHandler = new NettyHandler(getUrl(), this);channels = nettyHandler.getChannels();// https://issues.jboss.org/browse/NETTY-365// https://issues.jboss.org/browse/NETTY-379// final Timer timer = new HashedWheelTimer(new NamedThreadFactory("NettyIdleTimer", true));bootstrap.setPipelineFactory(new ChannelPipelineFactory() {public ChannelPipeline getPipeline() {NettyCodecAdapter adapter = new NettyCodecAdapter(getCodec() ,getUrl(), NettyServer.this);ChannelPipeline pipeline = Channels.pipeline();/*int idleTimeout = getIdleTimeout();if (idleTimeout > 10000) {pipeline.addLast("timer", new IdleStateHandler(timer, idleTimeout / 1000, 0, 0));}*/pipeline.addLast("decoder", adapter.getDecoder());//增加解码器pipeline.addLast("encoder", adapter.getEncoder());//增加编码器pipeline.addLast("handler", nettyHandler);//业务处理类return pipeline;}});// bindchannel = bootstrap.bind(getBindAddress());
}