8. 客户端实现

main.go | server.go | user.go | client.go

// client.go
package mainimport ("flag""fmt""io""net""os"
)type Client struct {ServerIp   stringServerPort intName       stringconn       net.Connflag       int
}// 创建一个客户端
func NewClient(serverIp string, serverPort int) *Client {client := &Client{ServerIp:   serverIp,ServerPort: serverPort,flag:       999,}// 连接服务器conn, err := net.Dial("tcp", fmt.Sprintf("%s:%d", serverIp, serverPort))if err != nil {fmt.Println("net.Dial error:", err)return nil}client.conn = connreturn client
}// 将服务端的消息打印到客户端
func (client *Client) DealResponse() {// 一旦 client.conn 有数据,copy 到 stdout 上, 永久阻塞监听io.Copy(os.Stdout, client.conn)
}// 展示功能目录
func (client *Client) menu() bool {var flag intfmt.Println("1. public chat")fmt.Println("2. private chat")fmt.Println("3. update username")fmt.Println("0. quit")fmt.Scanln(&flag)if 0 <= flag && flag <= 3 {client.flag = flagreturn true} else {fmt.Println(">>>>>>>>> please input a legal number ...")return false}
}// 公聊模式
func (client *Client) PublicChat() {var chatMsg stringfmt.Println(">>>>>>>>>> please input chat content, \"exit\" for quit")fmt.Scanln(&chatMsg)for chatMsg != "exit" {// 发送给服务器if len(chatMsg) != 0 {sendMsg := chatMsg + "\n"_, err := client.conn.Write([]byte(sendMsg))if err != nil {fmt.Println("conn Write err:", err)break}}chatMsg = ""fmt.Println(">>>>>>>>>> please input chat content, \"exit\" for quit")fmt.Scanln(&chatMsg)}
}// 查询在线用户
func (client *Client) SelectUsers() {sendMsg := "who\n"_, 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 stringvar chatMsg stringclient.SelectUsers()fmt.Println(">>>>>>>>>> please input chat userName, \"exit\" for quit")fmt.Scanln(&remoteName)for remoteName != "exit" {fmt.Println(">>>>>>>>>> please input chat content, \"exit\" for quit")fmt.Scanln(&chatMsg)for chatMsg != "exit" {if len(chatMsg) > 0 {sendMsg := "to|" + remoteName + "|" + chatMsg + "\n"_, err := client.conn.Write([]byte(sendMsg))if err != nil {fmt.Println("conn Write err:", err)break}}chatMsg = ""fmt.Println(">>>>>>>>>> please input chat content, \"exit\" for quit")fmt.Scanln(&chatMsg)}client.SelectUsers()fmt.Println(">>>>>>>>>> please input chat userName, \"exit\" for quit")fmt.Scanln(&remoteName)}
}// 修改当前客户端用户名
func (client *Client) UpdateName() bool {fmt.Println(">>>>>>>>>> please input username:")fmt.Scanln(&client.Name)sendMsg := "rename|" + client.Name + "\n"_, err := client.conn.Write([]byte(sendMsg))if err != nil {fmt.Println("conn.Write err:", err)return false}return true
}// 运行
func (client *Client) Run() {for client.flag != 0 {for client.menu() != true {}// 根据不同模式处理不同业务switch client.flag {case 1:// 公聊模式client.PublicChat()breakcase 2:// 私聊模式client.PrivateChat()breakcase 3:// 更新用户名client.UpdateName()break}}
}var serverIp string
var serverPort int// ./client -ip 127.0.0.1
func init() {flag.StringVar(&serverIp, "ip", "127.0.0.1", "设置服务器ip地址（默认 127.0.0.1）")flag.IntVar(&serverPort, "port", 8888, "设置服务器端口（默认 8888）")
}func main() {// client.exe -ip 127.0.0.1 -port 8888// 命令行解析flag.Parse()client := NewClient(serverIp, serverPort)if client == nil {fmt.Println(">>>>>>>>>> link to server failed ...")return}// 单独开启一个 goroutine 处理 server 的回执消息go client.DealResponse()fmt.Println(">>>>>>>>>> link to server succeed ...")// 启动客户端业务client.Run()
}