golang框架面试题集锦

package main

import (
    "<a style='color:#f60; text-decoration:underline;' href="https://www.codesou.cn/" target="_blank">git</a>hub.com/gin-gonic/gin"
    "<a style='color:#f60; text-decoration:underline;' href="https://www.codesou.cn/" target="_blank">golang</a>.org/x/time/rate"
    "time"
)

func main() {
    r := gin.Default()

    // 创建一个每秒允许 5 个请求的速率限制器
    limiter := rate.NewLimiter(5, 5)

    // 定义一个中间件，它使用速率限制器检查每个请求
    middleware := func(c *gin.Context) {
        if !limiter.Allow() {
            c.AbortWithStatus(http.StatusTooManyRequests)
            return
        }

        // 继续处理请求
        c.Next()
    }

    // 将中间件应用到所有路由
    r.Use(middleware)

    r.Run()
}

package main

import (
    "fmt"
    "github.com/gorilla/sessions"
    "github.com/gorilla/mux"
    "log"
    "net/http"
)

const (
    SessionName = "session-name"
    CookieName  = "session-id"
    Secret      = "secret-key"
)

var (
    sessionStore *sessions.CookieStore
)

func main() {
    // 创建 session 存储
    sessionStore = sessions.NewCookieStore([]byte(Secret))

    // 创建路由器
    r := mux.NewRouter()
    r.HandleFunc("/login", loginHandler)
    r.HandleFunc("/profile", profileHandler)

    // 启动服务器
    log.Fatal(http.ListenAndServe(":8080", r))
}

// loginHandler 处理登录请求并创建 session
func loginHandler(w http.ResponseWriter, r *http.Request) {
    // 创建 session
    session, err := sessionStore.Get(r, SessionName)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }

    // 将用户 ID 设置为 session 数据
    session.Values["user_id"] = 10

    // 保存 session
    if err = sessionStore.Save(r, w, session); err != nil {
       http.Error(w, err.Error(), http.StatusInternalServerError)
       return
    }

    // 重定向到个人资料页面
    http.Redirect(w, r, "/profile", http.StatusFound)
}

// profileHandler 处理个人资料请求并检索 session 数据
func profileHandler(w http.ResponseWriter, r *http.Request) {
    // 获取 session
    session, err := sessionStore.Get(r, SessionName)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }

    // 从 session 中检索用户 ID
    userID, ok := session.Values["user_id"].(int)
    if !ok {
        http.Error(w, "Invalid user ID in session", http.StatusBadRequest)
        return
    }

    // 使用用户 ID 渲染个人资料页面
    fmt.Fprintf(w, "Your profile page, user ID: %d", userID)
}