boost ASIO实例

client端代码

#include <iostream>
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
using boost::asio::ip::tcp;
class client
{
public:
    client(boost::asio::io_service& io_service,tcp::endpoint& endpoint)
        : socket(io_service)//这里就把socket实例化了
    {
        //连接服务端 connect
        socket.async_connect(endpoint,
            boost::bind(&client::handle_connect,this,boost::asio::placeholders::error)
            );
        memset(getBuffer,'',1024);
    }
    ~client()
    {}
private:
    void handle_connect(const boost::system::error_code& error)
    {
        if(!error)
        {
            //一连上，就向服务端发送信息
            boost::asio::async_write(socket,boost::asio::buffer("hello,server!"),
                boost::bind(&client::handle_write,this,boost::asio::placeholders::error));

            /**读取服务端发下来的信息
            *这里很奇怪，用async_read根本就不能进入handle_read函数
            **/

            // --已经解决，boost::asio::async_read(...)读取的字节长度不能大于数据流的长度，否则就会进入
            // ioservice.run()线程等待，read后面的就不执行了。
            //boost::asio::async_read(socket,
            //     boost::asio::buffer(getBuffer,1024),
            //     boost::bind(&client::handle_read,this,boost::asio::placeholders::error)
            //    );
            socket.async_read_some(boost::asio::buffer(getBuffer,1024),
                boost::bind(&client::handle_read,this,boost::asio::placeholders::error)
                );
        }
        else
        {
            socket.close();
        }
    }
    void handle_read(const boost::system::error_code& error)
    {
        if(!error)
        {
            std::cout << getBuffer << std::endl;
            //boost::asio::async_read(socket,
            //         boost::asio::buffer(getBuffer,1024),
            //         boost::bind(&client::handle_read,this,boost::asio::placeholders::error)
            //        );

            //这样就可以实现循环读取了，相当于while（1）
            //当然，到了这里，做过网络的朋友就应该相当熟悉了，一些逻辑就可以自行扩展了
            //想做聊天室的朋友可以用多线程来实现
            socket.async_read_some(
                boost::asio::buffer(getBuffer,1024),
                boost::bind(&client::handle_read,this,boost::asio::placeholders::error)
                );
        }
        else
        {
            socket.close();
        }
    }
    void handle_write(const boost::system::error_code& error)
    {
    }

private:
    tcp::socket socket;
    char getBuffer[1024];
};

int main(int argc,char* argv[])
{
    //if(argc != 3)
    //{
    // std::cerr << “Usage: chat_client <host> <port>
”;
    //    return 1;
    //}

    //我觉IO_SERVICE是一个基本性的接口，基本上通常用到的类实例都需要通过它来构造
    //功能我们可以看似socket
    boost::asio::io_service io_service;
    //这个终端就是服务器
    //它的定义就可以看作时sockaddr_in,我们用它来定义IP和PORT
    tcp::endpoint endpoint(boost::asio::ip::address_v4::from_string("127.0.0.1"/*argv[1]*/),8100/*argv[2]*/);
    //既然socket和sockaddr_in已经定义好了，那么，就可以CONNECT了
    //之所以为了要把连接和数据处理封成一个类，就是为了方便管理数据,这点在服务端就会有明显的感觉了
    boost::shared_ptr<client> client_ptr(new client(io_service,endpoint));
    //执行收发数据的函数
    io_service.run();
    return 0;
}

客户端代码

#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <iostream>
using boost::asio::ip::tcp;
#define max_len 1024
class clientSession
    :public boost::enable_shared_from_this<clientSession>
{
public:
    clientSession(boost::asio::io_service& ioservice)
        :m_socket(ioservice)
    {
        memset(data_,'',sizeof(data_));
    }
    ~clientSession()
    {}
    tcp::socket& socket()
    {
        return m_socket;
    }
    void start()
    {
        boost::asio::async_write(m_socket,
            boost::asio::buffer("link successed!"),
            boost::bind(&clientSession::handle_write,shared_from_this(),
            boost::asio::placeholders::error));

        /*async_read跟客户端一样，还是不能进入handle_read函数,如果你能找到问题所在，请告诉我，谢谢*/

        // --已经解决，boost::asio::async_read(...)读取的字节长度不能大于数据流的长度，否则就会进入
        // ioservice.run()线程等待，read后面的就不执行了。
        //boost::asio::async_read(m_socket,boost::asio::buffer(data_,max_len),

        //         boost::bind(&clientSession::handle_read,shared_from_this(),

        //         boost::asio::placeholders::error));
        //max_len可以换成较小的数字，就会发现async_read_some可以连续接收未收完的数据

        m_socket.async_read_some(boost::asio::buffer(data_,max_len),
            boost::bind(&clientSession::handle_read,shared_from_this(),
            boost::asio::placeholders::error));
    }
private:
    void handle_write(const boost::system::error_code& error)
    {

        if(error)
        {
            m_socket.close();
        }

    }
    void handle_read(const boost::system::error_code& error)
    {

        if(!error)
        {
            std::cout << data_ << std::endl;
            //boost::asio::async_read(m_socket,boost::asio::buffer(data_,max_len),

            //     boost::bind(&clientSession::handle_read,shared_from_this(),

            //     boost::asio::placeholders::error));

            m_socket.async_read_some(boost::asio::buffer(data_,max_len),
                boost::bind(&clientSession::handle_read,shared_from_this(),
                boost::asio::placeholders::error));
        }
        else
        {
            m_socket.close();
        }

    }
private:
    tcp::socket m_socket;
    char data_[max_len];
};

class serverApp
{
    typedef boost::shared_ptr<clientSession> session_ptr;
public:
    serverApp(boost::asio::io_service& ioservice,tcp::endpoint& endpoint)
        :m_ioservice(ioservice),
        acceptor_(ioservice,endpoint)
    {
        session_ptr new_session(new clientSession(ioservice));
        acceptor_.async_accept(new_session->socket(),
            boost::bind(&serverApp::handle_accept,this,boost::asio::placeholders::error,
            new_session));
    }
    ~serverApp()
    {
    }
private:
    void handle_accept(const boost::system::error_code& error,session_ptr& session)
    {
        if(!error)
        {
            std::cout << "get a new client!" << std::endl;
            //实现对每个客户端的数据处理

            session->start();
            //在这就应该看出为什么要封session类了吧，每一个session就是一个客户端

            session_ptr new_session(new clientSession(m_ioservice));
            acceptor_.async_accept(new_session->socket(),
                boost::bind(&serverApp::handle_accept,this,boost::asio::placeholders::error,
                new_session));
        }
    }
private:
    boost::asio::io_service& m_ioservice;
    tcp::acceptor acceptor_;
};

int main(int argc , char* argv[])
{
    boost::asio::io_service myIoService;
    short port = 8100/*argv[1]*/;
    //我们用的是inet4

    tcp::endpoint endPoint(tcp::v4(),port);
    //终端（可以看作sockaddr_in）完成后，就要accept了

    serverApp sa(myIoService,endPoint);
    //数据收发逻辑

    myIoService.run();
    return 0;
}