type Cookie struct {
    Name  string
    Value string

    Path       string    // optional
    Domain     string    // optional
    Expires    time.Time // optional
    RawExpires string    // for reading cookies only

    // MaxAge=0 means no 'Max-Age' attribute specified.
    // MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
    // MaxAge>0 means Max-Age attribute present and given in seconds
    MaxAge   int
    Secure   bool
    HttpOnly bool
    Raw      string
    Unparsed []string // Raw text of unparsed attribute-value pairs
}

cookie := http.Cookie{Name: "testcookiename", Value: "testcookievalue", Path: "/", MaxAge: 86400}
http.SetCookie(w, &cookie)

cookie, err := req.Cookie("testcookiename")

cookie := http.Cookie{Name: "testcookiename", Path: "/", MaxAge: -1}
http.SetCookie(w, &cookie)

package main

import (
    "net/http"
)

func SayHello(w http.ResponseWriter, req *http.Request) {
    w.Write([]byte("Hello"))
}

func ReadCookieServer(w http.ResponseWriter, req *http.Request) {
    // read cookie
    cookie, err := req.Cookie("testcookiename")
    if err == nil {
        cookievalue := cookie.Value
        w.Write([]byte("<b>cookie的值是：" + cookievalue + "</b>\n"))
    } else {
        w.Write([]byte("<b>讀取出現(xiàn)錯(cuò)誤：" + err.Error() + "</b>\n"))
    }
}

func WriteCookieServer(w http.ResponseWriter, req *http.Request) {
    cookie := http.Cookie{Name: "testcookiename", Value: "testcookievalue", Path: "/", MaxAge: 86400}
    http.SetCookie(w, &cookie)

    w.Write([]byte("<b>設(shè)置cookie成功。</b>\n"))
}

func DeleteCookieServer(w http.ResponseWriter, req *http.Request) {
    cookie := http.Cookie{Name: "testcookiename", Path: "/", MaxAge: -1}
    http.SetCookie(w, &cookie)

    w.Write([]byte("<b>刪除cookie成功,。</b>\n"))
}

func main() {
    http.HandleFunc("/", SayHello)
    http.HandleFunc("/readcookie", ReadCookieServer)
    http.HandleFunc("/writecookie", WriteCookieServer)
    http.HandleFunc("/deletecookie", DeleteCookieServer)

    http.ListenAndServe(":80", nil)
}