TCP/IP 网络编程 | 服务端 客户端的封装

设计模式

一、socket.h 接口（interface）

#ifndef SOCKET_H
#define SOCKET_H#include <string>
using std::string;class Socket
{
public:Socket();~Socket();bool bind(int port);bool listen(int backlog = 5);int accept();bool connect(const string &ip, int port);  // ✅ 客户端连接方法int fd() const { return m_sockfd; } // 可选：暴露 sockfd 方便客户端用private:int m_sockfd;
};#endif // SOCKET_H

二、socket.cpp 实现（implementation）

// socket.cpp
#include "socket.h"#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <cstring>
#include <cstdio>
#include <cerrno>using std::string;Socket::Socket()
{m_sockfd = ::socket(AF_INET, SOCK_STREAM, 0);if (m_sockfd < 0){printf("Socket creation failed: errno=%d, errmsg=%s\n", errno, strerror(errno));}
}Socket::~Socket()
{if (m_sockfd >= 0){::close(m_sockfd);}
}bool Socket::connect(const string &ip, int port)
{sockaddr_in addr;std::memset(&addr, 0, sizeof(addr));addr.sin_family = AF_INET;addr.sin_port = htons(port);if (::inet_pton(AF_INET, ip.c_str(), &addr.sin_addr) <= 0){printf("Invalid IP address: %s\n", ip.c_str());return false;}int ret = ::connect(m_sockfd, (struct sockaddr*)&addr, sizeof(addr));if (ret < 0){printf("Connect failed: errno=%d, errmsg=%s\n", errno, strerror(errno));return false;}return true;
}void Socket::close()
{if (m_sockfd >= 0){::close(m_sockfd);m_sockfd = -1;}
}

三、server.cpp 使用封装（main 函数）

#include "socket.h"#include <iostream>
#include <unistd.h>    // read(), write()
#include <cstring>     // memsetint main()
{Socket server;if (!server.bind(8888)){std::cerr << "Failed to bind port 8888" << std::endl;return 1;}if (!server.listen()){std::cerr << "Failed to listen on port 8888" << std::endl;return 1;}std::cout << "Server listening on port 8888..." << std::endl;while (true){int client_fd = server.accept();if (client_fd < 0){continue; // accept failed}char buffer[1024];ssize_t n = ::read(client_fd, buffer, sizeof(buffer) - 1);if (n > 0){buffer[n] = '\0';std::cout << "Received: " << buffer << std::endl;std::string response = "Echo: ";response += buffer;::write(client_fd, response.c_str(), response.size());}::close(client_fd);}return 0;
}

四、client.cpp 使用封装（main 函数）

#include "socket.h"#include <iostream>
#include <unistd.h>     // read(), write()
#include <cstring>      // strlen()int main()
{Socket client;if (!client.connect("127.0.0.1", 8888)){std::cerr << "Failed to connect to server." << std::endl;return 1;}std::cout << "Connected to server." << std::endl;std::string input;while (true){std::cout << "Enter message: ";std::getline(std::cin, input);if (input == "exit")break;::write(client.fd(), input.c_str(), input.size());char buffer[1024];ssize_t n = ::read(client.fd(), buffer, sizeof(buffer) - 1);if (n > 0){buffer[n] = '\0';std::cout << "Server response: " << buffer << std::endl;}else{std::cout << "Server closed connection." << std::endl;break;}}return 0;
}

五、退出方法

1. 客户端：
   当你在客户端输入：

Enter message: exit

客户端程序会退出（break 出循环）。

2. 服务器：
   • 当前版本是永不退出的死循环
   • 你可以使用 Ctrl+C 来中断服务器进程

六、终端输出

1. 终端 1：服务器

$ ./server
Server listening on port 8888...
Received: hello
Received: world

2. 终端 2：客户端

$ ./client
Connected to server.
Enter message: hello
Server response: Echo: helloEnter message: world
Server response: Echo: worldEnter message: exit