//下面程序取自 Poco 库的Net模块例子----HTTPServer 下面开始解析代码 #include "Poco/Net/HTTPServer.h" //继承自TCPServer 实现了一个完整的HTTP多线程服务器 #include "Poco/Net/HTTPRequestHandler.h" //抽象基类类 被HttpServer所创建 用来处理Http的请求 #include "Poco/Net/HTTPRequestHandlerFactory.h" //HTTPRequestHandler的工厂 给予工厂设计模式 #include "Poco/Net/HTTPServerParams.h" //被用来指定httpserver以及HTTPRequestHandler的参数 #include "Poco/Net/HTTPServerRequest.h" //ServerRequest的抽象子类用来指定 服务器端的 http请求 #include "Poco/Net/HTTPServerResponse.h" //ServerResponse的抽象子类用来指定服务器端的http响应 #include "Poco/Net/ServerSocket.h" //提供了一个TCP服务器套接字接口 #include "Poco/Net/WebSocket.h" //这个类实现了RFC 6455 web套接字接口 专门针对web服务器用 #include "Poco/Net/NetException.h" //网络异常 #include "Poco/Util/ServerApplication.h" //Application的子类 所有服务器程序 包括 Reactor FTP HTTP等都用到 算是服务器的启动类 #include "Poco/Util/Option.h" //存储了命令行选项 #include "Poco/Util/OptionSet.h" //一个Opention对象的集合 #include "Poco/Util/HelpFormatter.h" //从OptionSet格式化帮助信息 #include "Poco/Format.h" //格式化函数的实现类似于 C的 sprintf函数 具体看文档 #include <iostream> using Poco::Net::ServerSocket; using Poco::Net::WebSocket; using Poco::Net::WebSocketException; using Poco::Net::HTTPRequestHandler; using Poco::Net::HTTPRequestHandlerFactory; using Poco::Net::HTTPServer; using Poco::Net::HTTPServerRequest; using Poco::Net::HTTPResponse; using Poco::Net::HTTPServerResponse; using Poco::Net::HTTPServerParams; using Poco::Timestamp; using Poco::ThreadPool; using Poco::Util::ServerApplication; using Poco::Util::Application; using Poco::Util::Option; using Poco::Util::OptionSet; using Poco::Util::HelpFormatter; //////页面处理器 链接到来的时候 直接打印html内容 class PageRequestHandler: public HTTPRequestHandler /// Return a HTML document with some JavaScript creating /// a WebSocket connection. { public: void handleRequest(HTTPServerRequest& request, HTTPServerResponse& response) { response.setChunkedTransferEncoding(true); response.setContentType("text/html"); std::ostream& ostr = response.send(); ostr << "<html>"; ostr << "<head>"; ostr << "<title>WebSocketServer</title>"; ostr << "<script type=\"text/javascript\">"; ostr << "function WebSocketTest()"; ostr << "{"; ostr << " if (\"WebSocket\" in window)"; ostr << " {"; ostr << " var ws = new WebSocket(\"ws://" << request.serverAddress().toString() << "/ws\");"; ostr << " ws.onopen = function()"; ostr << " {"; ostr << " ws.send(\"Hello, world!\");"; ostr << " };"; ostr << " ws.onmessage = function(evt)"; ostr << " { "; ostr << " var msg = evt.data;"; ostr << " alert(\"Message received: \" + msg);"; ostr << " ws.close();"; ostr << " };"; ostr << " ws.onclose = function()"; ostr << " { "; ostr << " alert(\"WebSocket closed.\");"; ostr << " };"; ostr << " }"; ostr << " else"; ostr << " {"; ostr << " alert(\"This browser does not support WebSockets.\");"; ostr << " }"; ostr << "}"; ostr << "</script>"; ostr << "</head>"; ostr << "<body>"; ostr << " <h1>WebSocket Server</h1>"; ostr << " <p><a href=\"javascript:WebSocketTest()\">Run WebSocket Script</a></p>"; ostr << "</body>"; ostr << "</html>"; } }; /////////http请求处理器 1 class WebSocketRequestHandler: public HTTPRequestHandler /// Handle a WebSocket connection. { public: void handleRequest(HTTPServerRequest& request, HTTPServerResponse& response) { Application& app = Application::instance(); try { WebSocket ws(request, response); app.logger().information("WebSocket connection established."); char buffer[1024]; int flags; int n; do { n = ws.receiveFrame(buffer, sizeof(buffer), flags); app.logger().information(Poco::format("Frame received (length=%d, flags=0x%x).", n, unsigned(flags))); ws.sendFrame(buffer, n, flags); } while (n > 0 || (flags & WebSocket::FRAME_OP_BITMASK) != WebSocket::FRAME_OP_CLOSE); app.logger().information("WebSocket connection closed."); } catch (WebSocketException& exc) { app.logger().log(exc); switch (exc.code()) { case WebSocket::WS_ERR_HANDSHAKE_UNSUPPORTED_VERSION: response.set("Sec-WebSocket-Version", WebSocket::WEBSOCKET_VERSION); // fallthrough case WebSocket::WS_ERR_NO_HANDSHAKE: case WebSocket::WS_ERR_HANDSHAKE_NO_VERSION: case WebSocket::WS_ERR_HANDSHAKE_NO_KEY: response.setStatusAndReason(HTTPResponse::HTTP_BAD_REQUEST); response.setContentLength(0); response.send(); break; } } } }; //HTTP请求处理器工厂 class RequestHandlerFactory: public HTTPRequestHandlerFactory { public: HTTPRequestHandler* createRequestHandler(const HTTPServerRequest& request) //覆盖方法 { Application& app = Application::instance(); app.logger().information("Request from " + request.clientAddress().toString() + ": " + request.getMethod() + " " + request.getURI() + " " + request.getVersion()); //打印所有链接请求 for (HTTPServerRequest::ConstIterator it = request.begin(); it != request.end(); ++it) { app.logger().information(it->first + ": " + it->second); } //可以选择输出html页面 或者不输出 通过http请求参数 if(request.find("Upgrade") != request.end() && request["Upgrade"] == "websocket") return new WebSocketRequestHandler; else return new PageRequestHandler; } }; //////////网络应用程序的启动器 都是ServerApplication class WebSocketServer: public Poco::Util::ServerApplication { public: WebSocketServer(): _helpRequested(false) { } ~WebSocketServer() { } protected: ///再启动的时候先调用 void initialize(Application& self) { loadConfiguration(); // load default configuration files, if present ServerApplication::initialize(self); } //在释放的时候调用 void uninitialize() { ServerApplication::uninitialize(); } ///覆盖基类的函数 定义一些命令选项 void defineOptions(OptionSet& options) { ServerApplication::defineOptions(options); options.addOption( Option("help", "h", "display help information on command line arguments") .required(false) .repeatable(false)); } ///处理命令行选项 void handleOption(const std::string& name, const std::string& value) { ServerApplication::handleOption(name, value); if (name == "help") _helpRequested = true; } //打印帮助 void displayHelp() { HelpFormatter helpFormatter(options()); helpFormatter.setCommand(commandName()); helpFormatter.setUsage("OPTIONS"); helpFormatter.setHeader("A sample HTTP server supporting the WebSocket protocol."); helpFormatter.format(std::cout); } //在初始化完毕之后调用 int main(const std::vector<std::string>& args) { if (_helpRequested) { displayHelp(); } else { // get parameters from configuration file //从配置文件中获取端口 unsigned short port = (unsigned short) config().getInt("WebSocketServer.port", 9980); // 安装一个ServerSocket ServerSocket svs(port); // s安装一个HttpServer实例 并且传递 请求处理器工厂 和一个HttpServerParams对象 HTTPServer srv(new RequestHandlerFactory, svs, new HTTPServerParams); // 启动服务器 srv.start(); // 等待kill 或者控制台CTRL+C waitForTerminationRequest(); // 停止HTTP服务器 srv.stop(); } return Application::EXIT_OK; //返回正常退出状态 } private: bool _helpRequested; }; //启动web 服务器 POCO_SERVER_MAIN(WebSocketServer)
