Golang开发：实现基于WebSockets的实时数据推送

go get github.com/gorilla/websocket

package main

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

    "github.com/gorilla/websocket"
)

var clients = make(map[*websocket.Conn]bool) // connected clients
var broadcast = make(chan Message)           // broadcast channel

// Message 接收和发送的数据结构体
type Message struct {
    Message string `json:"message"`
}

func main() {
    // 创建一个简单的文件服务器，用于向客户端提供Web页面
    fs := http.FileServer(http.Dir("public"))
    http.Handle("/", fs)

    // 注册处理函数
    http.HandleFunc("/ws", handleConnections)

    // 启动消息广播协程
    go handleMessages()

    // 启动服务器
    fmt.Println("Server started on http://localhost:8000")
    err := http.ListenAndServe(":8000", nil)
    if err != nil {
        log.Fatal("ListenAndServe: ", err)
    }
}

func handleConnections(w http.ResponseWriter, r *http.Request) {
    // 升级HTTP连接为WebSockets
    ws, err := websocket.Upgrade(w, r, nil, 1024, 1024)
    if err != nil {
        log.Fatal(err)
    }

    // 当前连接关闭时，从全局连接池中删除
    defer func() {
        delete(clients, ws)
        ws.Close()
    }()

    // 将新的客户端连接添加到全局连接池中
    clients[ws] = true

    for {
        var msg Message
        // 读取客户端发送的消息
        err := ws.ReadJSON(&msg)
        if err != nil {
            log.Printf("error: %v", err)
            delete(clients, ws)
            break
        }
        // 将收到的消息发送到广播频道
        broadcast <- msg
    }
}

func handleMessages() {
    for {
        // 从广播频道接收消息
        msg := <-broadcast
        // 向所有客户端发送消息
        for client := range clients {
            err := client.WriteJSON(msg)
            if err != nil {
                log.Printf("error: %v", err)
                client.Close()
                delete(clients, client)
            }
        }
    }
}