从浏览器中获取cookie

从请求的首部获取cookie

语句r.Header[“Cookie”]返回了一个切片，这个切片包含了一个字符串，而这个字符串又包含了客户端发送的任意多个cookie。

package main
import (
   "fmt"
   "net/http"
)
func setCookie(w http.ResponseWriter, r *http.Request) {
c1 :=http.Cookie{
   Name: "fu",
   Value: "Go1",
   HttpOnly: true,
}
c2 :=http.Cookie{
   Name: "fu2",
   Value: "Go2",
   HttpOnly: true,
}
http.SetCookie(w,&c1)
http.SetCookie(w,&c2)
}
func getCookie(w http.ResponseWriter, r *http.Request)  {
   h :=r.Header["Cookie"]
   fmt.Fprintln(w,h)
}
func main() {
   server := http.Server{
      Addr:"127.0.0.1:8080",
   }
   http.HandleFunc("/set_cookie", setCookie)
   http.HandleFunc("/get_cookie", getCookie)
   server.ListenAndServe()
}

使用Cookie方法和Cookies

Go语言为Request结构提供了一个Cookie方法，这个方法可以获取指定名字的cookie。如果指定的cookie不存在，那么方法将返回一个错误。因为Cookie方法只能获取单个cookie，所以如果想要同时获取多个cookie，就需要用到Request结构的Cookies方法：Cookies方法可以返回一个包含了所有cookie的切片

package main

import (
   "fmt"
   "net/http"
)
func setCookie(w http.ResponseWriter, r *http.Request) {
c1 :=http.Cookie{
   Name: "fu",
   Value: "Go1",
   HttpOnly: true,
}
c2 :=http.Cookie{
   Name: "fu2",
   Value: "Go2",
   HttpOnly: true,
}
http.SetCookie(w,&c1)
http.SetCookie(w,&c2)
}
func getCookie(w http.ResponseWriter, r *http.Request)  {
   c1,err :=r.Cookie("fu")
   if err != nil {
      fmt.Fprintln(w,"Cannot get the first cookie")
   }
   cs :=r.Cookies()
   fmt.Fprintln(w,c1)
   fmt.Fprintln(w,cs)
}
func main() {
   server := http.Server{
      Addr:"127.0.0.1:8080",
   }
   http.HandleFunc("/set_cookie", setCookie)
   http.HandleFunc("/get_cookie", getCookie)
   server.ListenAndServe()
}