go webscoket-Go服务器开发

下面是一个简单的示例，展示如何使用Go语言编写一个基于WebSocket的服务器和客户端。

服务端代码（server.go）：

package main
import (
	"fmt"
	"log"
	"net/http"
	"github.com/gorilla/websocket"
)
var clients = make(map[*websocket.Conn]bool) // 存储所有连接的客户端
var broadcast = make(chan Message)           // 广播通道
// 定义消息结构体
type Message struct {
	Username string `json:"username"`
	Message  string `json:"message"`
}
func main() {
	http.HandleFunc("/ws", handleWebSocket)
	go startBroadcast()
	log.Println("Server is running on http://localhost:8080")
	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		log.Fatal("ListenAndServe: ", err)
	}
}
func handleWebSocket(w http.ResponseWriter, r *http.Request) {
	upgrader := websocket.Upgrader{
		CheckOrigin: func(r *http.Request) bool { return true },
	}
	conn, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		log.Println("Upgrade error:", err)
		return
	}
	defer conn.Close()
	log.Println("New client connected")
	clients[conn] = true
	for {
		var message Message
		err := conn.ReadJSON(&message)
		
        if err != nil {
			log.Printf("ReadJSON error: %v\n", err)
			delete(clients, conn)
			break
		}
        log.Printf("Received message from %s: %s\n", message.Username, message.Message)
        broadcast <- message
    }
}
func startBroadcast() {
	for {
        message := <-broadcast
        
        log.Printf("Broadcasting message from %s: %s\n", message.Username, message.Message)
        
        for client := range clients {
			err := client.WriteJSON(message)
			if err != nil {
				log.Printf("WriteJSON error: %v\n", err)
				client.Close()
				delete(clients, client)
			}
		}
    }
}

客户端代码（client.go）：

package main
import (
	"bufio"
	"fmt"
	"log"
	"net/url"
	"os"
	"github.com/gorilla/websocket"
)
func main() {
	reader := bufio.NewReader(os.Stdin)
	fmt.Print("Enter your username: ")
	username, _ := reader.ReadString('\n')
	u := url.URL{Scheme: "ws", Host: "localhost:8080", Path: "/ws"}
	log.Printf("Connecting to server %s...", u.String())
	conn, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
	if err != nil {
		log.Fatal("Dial error:", err)
	}
	defer conn.Close()
	go receiveMessages(conn)
	for {
        fmt.Print("Enter message (or 'exit' to quit): ")
        message, _ := reader.ReadString('\n')
        
        if message == "exit\n" {
            break
        }
        
        err = conn.WriteJSON(Message{
            Username: username,
            Message:  message,
        })
        
        if err != nil {
            log.Printf("WriteJSON error: %v\n", err)
            break
        }
    }
    log.Println("Disconnected from server")
}
func receiveMessages(conn *websocket.Conn) {
	for {
		var message Message
		err := conn.ReadJSON(&message)
		
        if err != nil {
			log.Printf("ReadJSON error: %v\n", err)
			break
		}
        log.Printf("[%s] %s\n", message.Username, message.Message)
    }
}