Go语言http之请求接收和处理 代码

package main

import (
    "encoding/json"
    "fmt"
    "github.com/julienschmidt/httprouter"
    "net/http"
)

//ResponseWriter是一个接口 拥有三个方法 Write WriteHeader的参数为响应码 Header方法
func Hello(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
    fmt.Fprintf(w, "hello ,%s
", p.ByName("name"))
}

//读取请求头
func headers(w http.ResponseWriter, r *http.Request) {
    //map[Accept:[*/*] Accept-Encoding:[gzip, deflate, br]
    // Cache-Control:[no-cache] Connection:[keep-alive] Content-Length:[42] Content-Type:[text/plain]
    // Postman-Token:[9d84b4f5-1b43-411a-89c3-fbd9c34d199f] User-Agent:[PostmanRuntime/7.24.0]]
    h := r.Header
    fmt.Fprintln(w, h)
}

//表单数据提交
func process(w http.ResponseWriter, r *http.Request) {
    r.ParseForm()
    fmt.Fprintln(w, r.Form) //map[hello:[sau sheong] post:[456]]
    //r.PostForm 是只获取表单键值对 不会回去URL键值对
}

func body(w http.ResponseWriter, r *http.Request) {
    len := r.ContentLength //获取主体数据的长度
    body := make([]byte, len)
    r.Body.Read(body)
    fmt.Fprintln(w, len)
    fmt.Fprintln(w, string(body))
}

//ResponseWriter返回json数据

type Post struct {
    User    string
    Threads []string
}

//向浏览器返回json数据
func jsonExample(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/json")
    post := &Post{
        User:    "zhangsan",
        Threads: []string{"nihao", "wohao"},
    }
    json, _ := json.Marshal(post) //Json Marshal：将数据编码成json字符串
    w.Write(json)
}

//向浏览器发送cookie
func setCookie(w http.ResponseWriter, r *http.Request) {
    c1 := http.Cookie{
        Name:     "first_cookie",
        Value:    "Go Web Programming",
        HttpOnly: true,
    }
    c2 := http.Cookie{
        Name:     "second_cookie",
        Value:    "Manning Programming",
        HttpOnly: true,
    }
    //w.Header().Set("Set-Cookie",c1.String())
    //w.Header().Add("Set-Cookie",c2.String())
    http.SetCookie(w, &c1)
    http.SetCookie(w, &c2) //三种设置cookie的方法
}

//从浏览器获得cookie
func getCookie(w http.ResponseWriter, r *http.Request) {
    h := r.Header["Cookie"]
    cs := r.Cookies()
    fmt.Fprintln(w, h)
    fmt.Fprintln(w, cs)
}

func main() {
    //mux:=httprouter.New()
    //mux.GET("/hello/:name",Hello)
    //log.Fatal(http.ListenAndServe(":8080",mux))
    //
    //http.HandleFunc("/header",headers)
    //http.HandleFunc("/body",body)
    //http.HandleFunc("/process",process)
    //http.HandleFunc("/json",jsonExample)
    http.HandleFunc("/setcookie", setCookie)
    http.HandleFunc("/getcookie", getCookie)

    http.ListenAndServe(":8080", nil)

}