经过一天的简单学习，尝试自己写一个简单的服务器，能够实现以下三大回调功能：onConnect onMessage onClose

下面直接贴出代码

1.BaseServer抽象类

BaseServer.h

/*
name：BaseServer
use：the basest server
author：hezijian(hezijian22@163.com)
*/

#ifdef _MSC_VER
#define _WIN32_WINNT 0x0501
#endif

#ifndef _BASE_SERVER_H_
#define _BASE_SERVER_H_

#include <boost/asio.hpp>

#include "SERVER_CONSTANT.h"


using namespace boost::asio;
using boost::system::error_code;
using ip::tcp;

class Session{
public:
	Session(io_service& iosev):
		m_buf((char*)malloc(SERVER_CONTANT::SESSION_BUF_LEN)),
		m_socket(iosev)
	{
		memset(m_buf,0,SERVER_CONTANT::SESSION_BUF_LEN);
	}
	~Session(){
		delete[] m_buf;
	}
	inline ip::tcp::socket& getSocket(){return m_socket;}
	inline char* getBuf(){return m_buf;}

private:
	ip::tcp::socket m_socket;
	char* m_buf;
};

class BaseServer
{
public:
	BaseServer(io_service &iosev);
	//初始化
	void init();

	//等待连接
	void start();
	
	//当有连接时
	void connect(std::shared_ptr<Session> pSession, error_code ec);

	//当有消息传递时
	void message(std::shared_ptr<Session> pSession, error_code ec);

	//当断开连接时
	void close(std::shared_ptr<Session> pSession, error_code ec);
	
	//以下是回调函数,由子类重写
	virtual void onConnect(std::shared_ptr<Session> pSession, error_code ec)=0;
	virtual void onMessage(std::shared_ptr<Session> pSession, error_code ec)=0;
	virtual void onClose(std::shared_ptr<Session> pSession, error_code ec)=0;


private:
	io_service &m_iosev;
	ip::tcp::acceptor m_acceptor;
	int m_unique_id;
};

#endif

#include "BaseServer.h"
#include <iostream>

BaseServer::BaseServer(io_service &iosev):
	m_iosev(iosev),m_acceptor(iosev, tcp::endpoint(tcp::v4(), SERVER_CONTANT::PORT)),m_unique_id(1){
		init();
}

void BaseServer::init(){
	return; 
}

void BaseServer::start(){
	std::shared_ptr<Session> pSession(new Session(m_iosev));

	m_acceptor.async_accept(pSession->getSocket(),
		std::bind(&BaseServer::connect,this, pSession, std::placeholders::_1));
}



void BaseServer::connect(std::shared_ptr<Session> pSession, error_code ec){
	std::cout << 
		"一个新的连接:" << pSession->getSocket().remote_endpoint().address()
 	    << std::endl;

	onConnect(pSession,ec);
	
	if(ec) return;
	//继续等待连接
	start();

	pSession->getSocket().async_read_some(buffer(pSession->getBuf(),SERVER_CONTANT::SESSION_BUF_LEN),
			std::bind(&BaseServer::message,this,pSession,std::placeholders::_1));
}

void BaseServer::message(std::shared_ptr<Session> pSession, error_code ec){
	if(ec){  
		BaseServer::close(pSession,ec);
		return;
	}
	std::cout << 
		"从客户端"<< pSession->getSocket().remote_endpoint().address() << "收到数据:" << pSession->getBuf()
		<< std::endl;

	onMessage(pSession,ec);

	//清空缓冲区,继续等待数据
	memset(pSession->getBuf(),0,sizeof(pSession->getBuf()));
	pSession->getSocket().async_read_some(buffer(pSession->getBuf(),SERVER_CONTANT::SESSION_BUF_LEN),
			std::bind(&BaseServer::message,this,pSession,std::placeholders::_1));
}

void BaseServer::close(std::shared_ptr<Session> pSession, error_code ec){
	std::cout << boost::system::system_error(ec).what() << std::endl;
	std::cout << pSession->getSocket().remote_endpoint().address() << " disconnect" << std::endl;
	pSession->getSocket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, const_cast<boost::system::error_code&>(ec));
	pSession->getSocket().close(const_cast<boost::system::error_code&>(ec));
	
	onClose(pSession,ec);

	return;  
}

Session暂时是一个包装了socket和buf的类，以后可能还会丰富修改

2.MyServer继承BaseServer

MyServer.h

#ifndef _MY_SERVER_H_
#define _MY_SERVER_H_
#include "BaseServer.h"

class MyServer : public BaseServer{
public:
	MyServer(io_service& iosev);

	virtual void onConnect(std::shared_ptr<Session> pSession, error_code ec);
	
	virtual void onMessage(std::shared_ptr<Session> pSession, error_code ec);

	virtual void onClose(std::shared_ptr<Session> pSession, error_code ec);
};
#endif

#include "MyServer.h"

MyServer::MyServer(io_service& iosev):BaseServer(iosev){

}
void MyServer::onConnect(std::shared_ptr<Session> pSession, error_code ec){

	printf("onConnect\n");
}
	
void MyServer::onMessage(std::shared_ptr<Session> pSession, error_code ec){
	
	printf("onMessage\n");
}

void MyServer::onClose(std::shared_ptr<Session> pSession, error_code ec){
	
	printf("onClose\n");
}

3.main函数

#include "MyServer.h"
#include <iostream>
int main(int argc, char* argv[])
{
	try{
		io_service iosev;
		MyServer sev(iosev);
		// 开始等待连接
		sev.start();

		std::cout << "服务器启动成功！" << std::endl;
		
		iosev.run();
		
	}catch(std::exception e){
		std::cout << e.what() << std::endl;
	}
	return 0;
}

基于boost::asio封装搭建的简单服务器