golang 即时通信系统

main.go

package main

func main() {
	server := NewServer("127.0.0.1", 8888)
	server.Start()
}

server.go

package main

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

type Server struct {
	Ip   string
	Port int

	//在线用户的列表
	OnlineMap map[string]*User
	mapLock   sync.RWMutex

	//消息广播的channel
	Message chan string
}

//创建一个server的接口
func NewServer(ip string, port int) *Server {
	server := &Server{
		Ip:        ip,
		Port:      port,
		OnlineMap: make(map[string]*User),
		Message:   make(chan string),
	}

	return server
}

//监听Message广播消息channel的goroutine，一旦有消息就发送给全部的在线User
func (this *Server) ListenMessager() {
	for {
		msg := <-this.Message

		//将msg发送给全部的在线User
		this.mapLock.Lock()
		for _, cli := range this.OnlineMap {
			cli.C <- msg
		}
		this.mapLock.Unlock()
	}
}

//广播消息的方法
func (this *Server) BroadCast(user *User, msg string) {
	sendMsg := "[" + user.Addr + "]" + user.Name + ":" + msg

	this.Message <- sendMsg
}

func (this *Server) Handler(conn net.Conn) {
	//...当前链接的业务
	//fmt.Println("链接建立成功")

	user := NewUser(conn, this)

	user.Online()

	//监听用户是否活跃的channel
	isLive := make(chan bool)

	//接受客户端发送的消息
	go func() {
		buf := make([]byte, 4096)
		for {
			n, err := conn.Read(buf)
			if n == 0 {
				user.Offline()
				return
			}

			if err != nil && err != io.EOF {
				fmt.Println("Conn Read err:", err)
				return
			}

			//提取用户的消息(去除'
')
			msg := string(buf[:n-1])

			//用户针对msg进行消息处理
			user.DoMessage(msg)

			//用户的任意消息，代表当前用户是一个活跃的
			isLive <- true
		}
	}()

	//当前handler阻塞
	for {
		select {
		case <-isLive:
			//当前用户是活跃的，应该重置定时器
			//不做任何事情，为了激活select，更新下面的定时器

		case <-time.After(time.Second * 300):
			//已经超时
			//将当前的User强制的关闭

			user.SendMsg("你被踢了")

			//销毁用的资源
			close(user.C)

			//关闭连接
			conn.Close()

			//退出当前Handler
			return //runtime.Goexit()
		}
	}
}

//启动服务器的接口
func (this *Server) Start() {
	//socket listen
	listener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", this.Ip, this.Port))
	if err != nil {
		fmt.Println("net.Listen err:", err)
		return
	}
	//close listen socket
	defer listener.Close()

	//启动监听Message的goroutine
	go this.ListenMessager()

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

		//do handler
		go this.Handler(conn)
	}
}

user.go

package main

import (
	"net"
	"strings"
)

type User struct {
	Name string
	Addr string
	C    chan string
	conn net.Conn

	server *Server
}

//创建一个用户的API
func NewUser(conn net.Conn, server *Server) *User {
	userAddr := conn.RemoteAddr().String()

	user := &User{
		Name: userAddr,
		Addr: userAddr,
		C:    make(chan string),
		conn: conn,

		server: server,
	}

	//启动监听当前user channel消息的goroutine
	go user.ListenMessage()

	return user
}

//用户的上线业务
func (this *User) Online() {

	//用户上线,将用户加入到onlineMap中
	this.server.mapLock.Lock()
	this.server.OnlineMap[this.Name] = this
	this.server.mapLock.Unlock()

	//广播当前用户上线消息
	this.server.BroadCast(this, "已上线")
}

//用户的下线业务
func (this *User) Offline() {

	//用户下线,将用户从onlineMap中删除
	this.server.mapLock.Lock()
	delete(this.server.OnlineMap, this.Name)
	this.server.mapLock.Unlock()

	//广播当前用户上线消息
	this.server.BroadCast(this, "下线")

}

//给当前User对应的客户端发送消息
func (this *User) SendMsg(msg string) {
	this.conn.Write([]byte(msg))
}

//用户处理消息的业务
func (this *User) DoMessage(msg string) {
	if msg == "who" {
		//查询当前在线用户都有哪些

		this.server.mapLock.Lock()
		for _, user := range this.server.OnlineMap {
			onlineMsg := "[" + user.Addr + "]" + user.Name + ":" + "在线...
"
			this.SendMsg(onlineMsg)
		}
		this.server.mapLock.Unlock()

	} else if len(msg) > 7 && msg[:7] == "rename|" {
		//消息格式: rename|张三
		newName := strings.Split(msg, "|")[1]

		//判断name是否存在
		_, ok := this.server.OnlineMap[newName]
		if ok {
			this.SendMsg("当前用户名被使用
")
		} else {
			this.server.mapLock.Lock()
			delete(this.server.OnlineMap, this.Name)
			this.server.OnlineMap[newName] = this
			this.server.mapLock.Unlock()

			this.Name = newName
			this.SendMsg("您已经更新用户名:" + this.Name + "
")
		}

	} else if len(msg) > 4 && msg[:3] == "to|" {
		//消息格式:  to|张三|消息内容

		//1 获取对方的用户名
		remoteName := strings.Split(msg, "|")[1]
		if remoteName == "" {
			this.SendMsg("消息格式不正确，请使用 "to|张三|你好啊"格式。
")
			return
		}

		//2 根据用户名 得到对方User对象
		remoteUser, ok := this.server.OnlineMap[remoteName]
		if !ok {
			this.SendMsg("该用户名不不存在
")
			return
		}

		//3 获取消息内容，通过对方的User对象将消息内容发送过去
		content := strings.Split(msg, "|")[2]
		if content == "" {
			this.SendMsg("无消息内容，请重发
")
			return
		}
		remoteUser.SendMsg(this.Name + "对您说:" + content)

	} else {
		this.server.BroadCast(this, msg)
	}
}

//监听当前User channel的 方法,一旦有消息，就直接发送给对端客户端
func (this *User) ListenMessage() {
	for {
		msg := <-this.C

		this.conn.Write([]byte(msg + "
"))
	}
}

client.go

package main

import (
	"flag"
	"fmt"
	"io"
	"net"
	"os"
)

type Client struct {
	ServerIp   string
	ServerPort int
	Name       string
	conn       net.Conn
	flag       int //当前client的模式
}

func NewClient(serverIp string, serverPort int) *Client {
	//创建客户端对象
	client := &Client{
		ServerIp:   serverIp,
		ServerPort: serverPort,
		flag:       999,
	}

	//链接server
	conn, err := net.Dial("tcp", fmt.Sprintf("%s:%d", serverIp, serverPort))
	if err != nil {
		fmt.Println("net.Dial error:", err)
		return nil
	}

	client.conn = conn

	//返回对象
	return client
}

//处理server回应的消息， 直接显示到标准输出即可
func (client *Client) DealResponse() {
	//一旦client.conn有数据，就直接copy到stdout标准输出上, 永久阻塞监听
	io.Copy(os.Stdout, client.conn)
}

func (client *Client) menu() bool {
	var flag int

	fmt.Println("1.公聊模式")
	fmt.Println("2.私聊模式")
	fmt.Println("3.更新用户名")
	fmt.Println("0.退出")

	fmt.Scanln(&flag)

	if flag >= 0 && flag <= 3 {
		client.flag = flag
		return true
	} else {
		fmt.Println(">>>>请输入合法范围内的数字<<<<")
		return false
	}

}

//查询在线用户
func (client *Client) SelectUsers() {
	sendMsg := "who
"
	_, err := client.conn.Write([]byte(sendMsg))
	if err != nil {
		fmt.Println("conn Write err:", err)
		return
	}
}

//私聊模式
func (client *Client) PrivateChat() {
	var remoteName string
	var chatMsg string

	client.SelectUsers()
	fmt.Println(">>>>请输入聊天对象[用户名], exit退出:")
	fmt.Scanln(&remoteName)

	for remoteName != "exit" {
		fmt.Println(">>>>请输入消息内容, exit退出:")
		fmt.Scanln(&chatMsg)

		for chatMsg != "exit" {
			//消息不为空则发送
			if len(chatMsg) != 0 {
				sendMsg := "to|" + remoteName + "|" + chatMsg + "

"
				_, err := client.conn.Write([]byte(sendMsg))
				if err != nil {
					fmt.Println("conn Write err:", err)
					break
				}
			}

			chatMsg = ""
			fmt.Println(">>>>请输入消息内容, exit退出:")
			fmt.Scanln(&chatMsg)
		}

		client.SelectUsers()
		fmt.Println(">>>>请输入聊天对象[用户名], exit退出:")
		fmt.Scanln(&remoteName)
	}
}

func (client *Client) PublicChat() {
	//提示用户输入消息
	var chatMsg string

	fmt.Println(">>>>请输入聊天内容，exit退出.")
	fmt.Scanln(&chatMsg)

	for chatMsg != "exit" {
		//发给服务器

		//消息不为空则发送
		if len(chatMsg) != 0 {
			sendMsg := chatMsg + "
"
			_, err := client.conn.Write([]byte(sendMsg))
			if err != nil {
				fmt.Println("conn Write err:", err)
				break
			}
		}

		chatMsg = ""
		fmt.Println(">>>>请输入聊天内容，exit退出.")
		fmt.Scanln(&chatMsg)
	}

}

func (client *Client) UpdateName() bool {

	fmt.Println(">>>>请输入用户名:")
	fmt.Scanln(&client.Name)

	sendMsg := "rename|" + client.Name + "
"
	_, err := client.conn.Write([]byte(sendMsg))
	if err != nil {
		fmt.Println("conn.Write err:", err)
		return false
	}

	return true
}

func (client *Client) Run() {
	for client.flag != 0 {
		for client.menu() != true {
		}

		//根据不同的模式处理不同的业务
		switch client.flag {
		case 1:
			//公聊模式
			client.PublicChat()
			break
		case 2:
			//私聊模式
			client.PrivateChat()
			break
		case 3:
			//更新用户名
			client.UpdateName()
			break
		}
	}
}

var serverIp string
var serverPort int

//./client -ip 127.0.0.1 -port 8888
func init() {
	flag.StringVar(&serverIp, "ip", "127.0.0.1", "设置服务器IP地址(默认是127.0.0.1)")
	flag.IntVar(&serverPort, "port", 8888, "设置服务器端口(默认是8888)")
}

func main() {
	//命令行解析
	flag.Parse()

	client := NewClient(serverIp, serverPort)
	if client == nil {
		fmt.Println(">>>>> 链接服务器失败...")
		return
	}

	//单独开启一个goroutine去处理server的回执消息
	go client.DealResponse()

	fmt.Println(">>>>>链接服务器成功...")

	//启动客户端的业务
	client.Run()
}