Go语言编写一个简易聊天室服务端的实现

package main

import (
    "fmt"
    "net"
    "sync"
    "time"
)

type Client struct {
    conn     net.Conn
    username string
}

type ChatServer struct {
    clients map[*Client]bool
    lock    sync.Mutex
}

func NewChatServer() *ChatServer {
    return &ChatServer{
        clients: make(map[*Client]bool),
    }
}

func (server *ChatServer) addClient(client *Client) {
    server.lock.Lock()
    defer server.lock.Unlock()
    server.clients[client] = true
}

func (server *ChatServer) removeClient(client *Client) {
    server.lock.Lock()
    defer server.lock.Unlock()
    delete(server.clients, client)
}

func (server *ChatServer) broadcastMessage(message string, sender *Client) {
    server.lock.Lock()
    defer server.lock.Unlock()

    for client := range server.clients {
        if client != sender {
            _, err := client.conn.Write([]byte(message))
            if err != nil {
                fmt.Println("发送消息失败:", err)
            }
        }
    }
}

func handleConnection(conn net.Conn, server *ChatServer) {
    defer conn.Close()
    var client *Client

    fmt.Println("新的客户端连接:", conn.RemoteAddr())

    // 为每个客户端创建唯一的连接对象
    client = &Client{conn: conn}

    // 发送欢迎信息
    conn.Write([]byte("欢迎加入聊天室! 请输入你的昵称:\n"))

    // 获取用户名
    var username string
    fmt.Fscan(conn, &username)
    client.username = username
    server.addClient(client)

    // 向所有客户端广播消息，通知新用户加入
    server.broadcastMessage(client.username+" 加入了聊天室\n", client)

    // 处理客户端消息
    go func() {
        reader := make([]byte, 1024)
        for {
            length, err := conn.Read(reader)
            if err != nil {
                fmt.Println("客户端断开:", client.username)
                server.removeClient(client)
                break
            }
            message := fmt.Sprintf("%s: %s", client.username, string(reader[:length]))
            server.broadcastMessage(message+"\n", client)
        }
    }()

    // 保持主线程
    for {
        time.Sleep(time.Second * 1)
    }
}

func main() {
    server := NewChatServer()

    // 启动服务器并监听端口
    listener, err := net.Listen("tcp", ":8080")
    if err != nil {
        fmt.Println("无法启动服务器:", err)
        return
    }
    defer listener.Close()

    fmt.Println("聊天室服务端已启动，监听端口 8080...")

    for {
        conn, err := listener.Accept()
        if err != nil {
            fmt.Println("连接错误:", err)
            continue
        }

        go handleConnection(conn, server)
    }
}

package main

import (
    "fmt"
    "net"
    "os"
    "bufio"
    "strings"
)

func main() {
    fmt.Print("请输入聊天室服务器的IP地址: ")
    var serverIP string
    fmt.Scanln(&serverIP)

    conn, err := net.Dial("tcp", serverIP+":8080")
    if err != nil {
        fmt.Println("连接服务器失败:", err)
        return
    }
    defer conn.Close()

    fmt.Print("请输入你的昵称: ")
    var username string
    fmt.Scanln(&username)

    conn.Write([]byte(username + "\n"))

    // 读取服务器的消息并显示
    go func() {
        reader := bufio.NewReader(conn)
        for {
            message, _ := reader.ReadString('\n')
            fmt.Print(message)
        }
    }()

    // 输入消息并发送到服务器
    for {
        fmt.Print("请输入消息: ")
        reader := bufio.NewReader(os.Stdin)
        message, _ := reader.ReadString('\n')
        message = strings.TrimSpace(message)

        if message == "exit" {
            fmt.Println("退出聊天室...")
            break
        }

        conn.Write([]byte(message + "\n"))
    }
}

go run server.go

go run client.go

go func() {
    reader := make([]byte, 1024)
    for {
        length, err := conn.Read(reader)
        if err != nil {
            fmt.Println("客户端断开:", client.username)
            server.removeClient(client)
            break
        }
        message := fmt.Sprintf("%s: %s", client.username, string(reader[:length]))
        server.broadcastMessage(message+"\n", client)
    }
}()

func (server *ChatServer) broadcastMessage(message string, sender *Client) {
    server.lock.Lock()
    defer server.lock.Unlock()

    for client := range server.clients {
        if client != sender {
            _, err := client.conn.Write([]byte(message))
            if err != nil {
                fmt.Println("发送消息失败:", err)
            }
        }
    }
}

server.removeClient(client)