golang의 Websocket을 사용하여 실시간 알림 기능을 개발하는 방법

go get github.com/gorilla/websocket

import (
    "github.com/gorilla/websocket"
    "net/http"
)

var upgrader = websocket.Upgrader{
    ReadBufferSize:  1024,
    WriteBufferSize: 1024,
}

func websocketHandler(w http.ResponseWriter, r *http.Request) {
    // 升级HTTP连接为Websocket连接
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        // 处理连接错误
        log.Println(err)
        return
    }
    
    // 在此处处理Websocket连接
    defer conn.Close()
    
    // 循环接收和发送消息
    for {
        // 读取消息
        _, message, err := conn.ReadMessage()
        if err != nil {
            // 处理读取错误
            log.Println(err)
            break
        }
        
        // 处理接收到的消息
        log.Println(string(message))
        
        // 发送消息
        err = conn.WriteMessage(websocket.TextMessage, message)
        if err != nil {
            // 处理写入错误
            log.Println(err)
            break
        }
    }
}

http.HandleFunc("/websocket", websocketHandler)

log.Fatal(http.ListenAndServe(":8080", nil))

var socket = new WebSocket("ws://localhost:8080/websocket");

socket.onopen = function(event) {
    console.log("Websocket connected.");
}

socket.onmessage = function(event) {
    console.log("Received message:", event.data);
}

socket.onclose = function(event) {
    console.log("Websocket closed.");
}

// 发送消息
socket.send("Hello, server!");

func sendNotification(conn *websocket.Conn, message string) {
    // 发送消息
    err := conn.WriteMessage(websocket.TextMessage, []byte(message))
    if err != nil {
        log.Println(err)
    }
}