golang使用websocket

要在Golang中使用WebSocket，你可以使用`github.com/gorilla/websocket`包。首先，你需要安装该包：

go get github.com/gorilla/websocket

然后，你可以使用以下代码示例创建WebSocket服务器和客户端：

// 服务器端
package main

import (
	"fmt"
	"log"
	"net/http"

	"github.com/gorilla/websocket"
)

// 处理WebSocket连接
func handleWebSocket(w http.ResponseWriter, r *http.Request) {
	// 升级HTTP连接为WebSocket协议
	conn, err := websocket.Upgrade(w, r, nil, 1024, 1024)
	if err != nil {
		log.Println(err)
		return
	}
	defer conn.Close()

	// 在这里处理WebSocket消息
	for {
		// 读取客户端发送的消息
		_, msg, err := conn.ReadMessage()
		if err != nil {
			log.Println(err)
			break
		}
		fmt.Println(string(msg))

		// 发送消息给客户端
		if err := conn.WriteMessage(websocket.TextMessage, []byte("Hello from server")); err != nil {
			log.Println(err)
			break
		}
	}
}

func main() {
	http.HandleFunc("/", handleWebSocket)
	log.Fatal(http.ListenAndServe(":8080", nil))
}

// 客户端
package main

import (
	"fmt"
	"log"
	"net/url"
	"os"
	"os/signal"
	"time"

	"github.com/gorilla/websocket"
)

func main() {
	interrupt := make(chan os.Signal, 1)
	signal.Notify(interrupt, os.Interrupt)

	u := url.URL{Scheme: "ws", Host: "localhost:8080", Path: "/"}
	log.Printf("connecting to %s", u.String())

	c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
	if err != nil {
		log.Fatal("dial:", err)
	}
	defer c.Close()

	done := make(chan struct{})

	// 接收和处理服务端发送的消息
	go func() {
		defer close(done)
		for {
			_, message, err := c.ReadMessage()
			if err != nil {
				log.Println("read:", err)
				return
			}
			fmt.Printf("received: %s\n", message)
		}
	}()

	// 定期向服务端发送消息
	ticker := time.NewTicker(time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-done:
			return
		case t := <-ticker.C:
			err := c.WriteMessage(websocket.TextMessage, []byte(t.String()))
			if err != nil {
				log.Println("write:", err)
				return
			}
		case <-interrupt:
			log.Println("interrupt")
			err := c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
			if err != nil {
				log.Println("write close:", err)
				return
			}
			select {
			case <-done:
			case <-time.After(time.Second):
			}
			return
		}
	}
}

这是一个简单的示例，服务器接收客户端的消息并将其打印出来，然后向客户端发送"Hello from server"的消息。客户端定期向服务器发送当前时间。