Poco C++库网络模块例子解析2——-HttpServer

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//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)

转载于:https://www.cnblogs.com/yuedongwei/p/4122340.html