net/http包提供了HTTP客户端和服务端的实现
超文本传输协议（HTTP，HyperText Transfer Protocol)是互联网上应用最为广泛的一种网络传输协议
所有的WWW文件都必须遵守这个标准。设计HTTP最初的目的是为了提供一种发布和接收HTML页面的方法。

1.HTTP客户端

1.2GET请求

  1. resp, err := http.Get("https://www.bilibili.com/")
  2. if err != nil {
  3.     fmt.Printf("get failed,err:%v\n",err)
  4.     return
  5. }
  6. defer resp.Body.Close()
  7. body, err := ioutil.ReadAll(resp.Body)
  8. if err != nil {
  9.     fmt.Printf("read failed,err:%v\n",err)
  10.     return
  11. }
  12. fmt.Println(string(body))

1.3带参数的GET请求

关于GET请求的参数需要使用Go语言内置的net/url这个标准库来处理

  1. import (
  2.     "fmt"
  3.     "io/ioutil"
  4.     "net/http"
  5.     "net/url"
  6. )
  8. func main() {
  9.     apiUrl := "http://127.0.0.1:9000/get"
  10.     u, err := url.ParseRequestURI(apiUrl)
  11.     if err != nil {
  12.         fmt.Printf("parse failed,err:%v\n",err)
  13.     }
  14.     fmt.Printf("%T\n",u)   //*url.URL
  15.     fmt.Println(u)   //http://127.0.0.1:9000/get
  16.     data := url.Values{}
  17.     data.Set("name","cheng")
  18.     data.Set("age","18")
  19.     //encode := data.Encode()
  20.     //fmt.Println(encode)  //age=18&name=cheng
  21.     u.RawQuery = data.Encode()
  22.     fmt.Println(u)   //http://127.0.0.1:9000/get
  23.     resp, err := http.Get(u.String())
  24.     if err != nil {
  25.         fmt.Printf("get failed,err:%v",err)
  26.         return
  27.     }
  28.     defer resp.Body.Close()
  29.     body, err := ioutil.ReadAll(resp.Body)
  30.     if err != nil {
  31.         fmt.Printf("get failed,err:%v",err)
  32.         return
  33.     }
  34.     fmt.Println(string(body))
  35. }

对应的Server端HandlerFunc

  1. func getHandler(w http.ResponseWriter, r *http.Request) {
  2.     defer r.Body.Close()
  3.     data := r.URL.Query()
  4.     fmt.Println(data.Get("name"))
  5.     fmt.Println(data.Get("age"))
  6.     answer := `{"status": "ok"}`
  7.     w.Write([]byte(answer))
  8. }

2.Post请求

  1. url := "http://127.0.0.1:9090/post"
  2. contentType := "application/json"
  3. data := `{name:"cheng",age:"18"}`
  4. resp, err := http.Post(url, contentType, strings.NewReader(data))
  5. if err != nil {
  6.     fmt.Printf("post failed,err:%v\n",err)
  7.     return
  8. }
  9. defer resp.Body.Close()
  10. body, err := ioutil.ReadAll(resp.Body)
  11. if err != nil {
  12.     fmt.Printf("get failed,err:%v\n",err)
  13.     return
  14. }
  15. fmt.Println(string(body))
  1. url := "http://www.bilibili.com/"
  2. contentType := "application/json"
  3. data := ``
  4. resp, err := http.Post(url, contentType, strings.NewReader(da
  5. if err != nil {
  6.     fmt.Printf("post failed,err:%v\n",err)
  7.     return
  8. }
  9. defer resp.Body.Close()
  10. body, err := ioutil.ReadAll(resp.Body)
  11. if err != nil {
  12.     fmt.Printf("get failed,err:%v\n",err)
  13.     return
  14. }
  15. fmt.Println(string(body))

对应的Server端HandlerFunc

  1. func postHandler(w http.ResponseWriter, r *http.Request){
  2.     defer r.Body.Close()
  3.     r.ParseForm()
  4.     fmt.Println(r.PostForm)  //打印form数据
  5.     fmt.Println(r.PostForm.Get("name"),r.PostForm.Get("age"))
  6.     body, err := ioutil.ReadAll(r.Body)
  7.     if err != nil {
  8.         fmt.Printf("read failed,err:%v",err)
  9.         return
  10.     }
  11.     fmt.Println(string(body))
  12.     answer := `{"status"："ok"}`
  13.     w.Write([]byte(answer))
  14. }

3.默认的Server

net/http包是对net包的进一步封装，专门用来处理HTTP协议的数据。

  1. func sayHello(w http.ResponseWriter,r *http.Request)  {
  2.     fmt.Fprint(w,"HelloWorld")
  3. }
  4. func main() {
  5.     http.HandleFunc("/",sayHello)
  6.     err := http.ListenAndServe(":9000", nil)
  7.     if err != nil {
  8.         fmt.Printf("http server failed,err:%v\n",err)
  9.         return
  10.     }
  11. }