【Golang 即时通讯系统V5】在线用户查询

user.go

package main

import "net"

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
}

// 用户的上线功能
func (this *User) Online() {
	// 用户上线,将用户加入到OnlineMap中
	this.server.mapLock.Lock()
	this.server.OnlineMap[user.Name] = this
	this.server.mapLock.Unlock()
	// 广播当前用户上线消息
	this.server.Broadcast(this, "已上线")
}

// 用户的下线功能
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()
  // 广播当前用户下线消息
  this.server.Broadcast(this, "已下线")
}
// 给当前user对应的客户端发消息
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...\n"
	this.sendMsg(onlineMsg)
}
this.server.mapLock.Unlock()
	} else {
		this.Broadcast(user, msg)
	}
}

// 监听当前user channel的方法，一旦有消息就直接发送给客户端
func (this *User) ListenMessage() {
	for {
		msg := <-this.C
		this.conn.Write([]byte(msg + "\n"))
	}
}