3.核心代码解析 a.DubboProtocol
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:20882 DubboExporter<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 event Boolean 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heartbeat url = 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; |
