Go语言内置的net/http
包十分的优秀,提供了HTTP客户端和服务端的实现。
net/http介绍
Go语言内置的net/http
包提供了HTTP客户端和服务端的实现。
HTTP协议
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。
HTTP客户端
基本的HTTP/HTTPS请求
Get、Head、Post和PostForm函数发出HTTP/HTTPS请求。
resp, err := http.Get("http://example.com/") ... resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf) ... resp, err := http.PostForm("http://example.com/form", url.Values{"key": {"Value"}, "id": {"123"}})
程序在使用完response后必须关闭回复的主体。
resp, err := http.Get("http://example.com/") if err != nil { // handle error } defer resp.Body.Close() body, err := ioutil.ReadAll(resp.Body) // ...
[GET]
package main import ( "fmt" "io/ioutil" "net/http" ) func main() { resp, err := http.Get("https://www.liwenzhou.com/") if err != nil { fmt.Printf("get failed, err:%v\n", err) return } defer resp.Body.Close() body, err := ioutil.ReadAll(resp.Body) if err != nil { fmt.Printf("read from resp.Body failed, err:%v\n", err) return } fmt.Print(string(body)) }
带参数:
参数需要使用到net/url来处理
func main() { apiUrl := "http://127.0.0.1:9090/get" // URL param data := url.Values{} data.Set("name", "mi") data.Set("age", "18") u, err := url.ParseRequestURI(apiUrl) if err != nil { fmt.Printf("parse url requestUrl failed, err:%v\n", err) } u.RawQuery = data.Encode() // URL encode fmt.Println(u.String()) resp, err := http.Get(u.String()) if err != nil { fmt.Printf("post failed, err:%v\n", err) return } defer resp.Body.Close() b, err := ioutil.ReadAll(resp.Body) if err != nil { fmt.Printf("get resp failed, err:%v\n", err) return } fmt.Println(string(b)) }
带header头部信息:
import ( "net/http" ) url := "https://b959e645-00ae-4bc3-8a55-7224d08b1d91.mock.pstmn.io/user/1" req, _ := http.NewRequest("GET", url, nil) req.Header.Add("Authorization", "xxxx") response, err := http.DefaultClient.Do(req)
对应server端:
func getHandler(w http.ResponseWriter, r *http.Request) { defer r.Body.Close() data := r.URL.Query() fmt.Println(data.Get("name")) fmt.Println(data.Get("age")) answer := `{"status": "ok"}` w.Write([]byte(answer)) }
[POST]
package main import ( "fmt" "io/ioutil" "net/http" "strings" ) // net/http post demo func main() { url := "http://127.0.0.1:9090/post" // 表单数据 //contentType := "application/x-www-form-urlencoded" //data := "name=mi&age=18" // json contentType := "application/json" data := `{"name":"mi","age":18}` resp, err := http.Post(url, contentType, strings.NewReader(data)) if err != nil { fmt.Printf("post failed, err:%v\n", err) return } defer resp.Body.Close() b, err := ioutil.ReadAll(resp.Body) if err != nil { fmt.Printf("get resp failed, err:%v\n", err) return } fmt.Println(string(b)) }
PostForm方式
func httpPostForm() { resp, err := http.PostForm("http://www.01happy.com/demo/accept.php", url.Values{"key": {"Value"}, "id": {"123"}}) if err != nil { // handle error } defer resp.Body.Close() body, err := ioutil.ReadAll(resp.Body) if err != nil { // handle error } fmt.Println(string(body)) }
json:
func testPostJson() { data := make(map[string]interface{}) data["site"] = "www.360.com" data["name"] = "xxx" bytesData, _ := json.Marshal(data) resp, _ := http.Post("http://httpbin.org/post", "application/json", bytes.NewReader(bytesData)) body, _ := ioutil.ReadAll(resp.Body) fmt.Println(string(body)) }
带有headers参数
func httpDo() { client := &http.Client{} req, err := http.NewRequest("POST", "http://www.01happy.com/demo/accept.php", strings.NewReader("name=cjb")) if err != nil { // handle error } req.Header.Set("Content-Type", "application/x-www-form-urlencoded") req.Header.Set("Cookie", "name=anny") resp, err := client.Do(req) defer resp.Body.Close() body, err := ioutil.ReadAll(resp.Body) if err != nil { // handle error } fmt.Println(string(body)) }
对应server端:
func postHandler(w http.ResponseWriter, r *http.Request) { defer r.Body.Close() // 1. 请求类型是application/x-www-form-urlencoded时解析form数据 r.ParseForm() fmt.Println(r.PostForm) // 打印form数据 fmt.Println(r.PostForm.Get("name"), r.PostForm.Get("age")) // 2. 请求类型是application/json时从r.Body读取数据 b, err := ioutil.ReadAll(r.Body) if err != nil { fmt.Printf("read request.Body failed, err:%v\n", err) return } fmt.Println(string(b)) answer := `{"status": "ok"}` w.Write([]byte(answer)) }
自定义Client
要管理HTTP客户端的头域、重定向策略和其他设置,创建一个Client:
client := &http.Client{ CheckRedirect: redirectPolicyFunc, } resp, err := client.Get("http://example.com") // ... req, err := http.NewRequest("GET", "http://example.com", nil) // ... req.Header.Add("If-None-Match", `W/"wyzzy"`) resp, err := client.Do(req)
自定义Transport
要管理代理、TLS配置、keep-alive、压缩和其他设置,创建一个Transport:
tr := &http.Transport{ TLSClientConfig: &tls.Config{RootCAs: pool}, DisableCompression: true, } client := &http.Client{Transport: tr} resp, err := client.Get("https://example.com")
Client和Transport类型都可以安全的被多个goroutine同时使用。出于效率考虑,应该一次建立、尽量重用。
服务端
默认的Server
ListenAndServe使用指定的监听地址和处理器启动一个HTTP服务端。处理器参数通常是nil,这表示采用包变量DefaultServeMux作为处理器。
Handle和HandleFunc函数可以向DefaultServeMux添加处理器。
http.Handle("/foo", fooHandler) http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) { fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path)) }) log.Fatal(http.ListenAndServe(":8080", nil))
默认的Server示例
使用Go语言中的net/http
包来编写一个简单的接收HTTP请求的Server端示例,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。具体的代码如下:
package main import ( "fmt" "net/http" ) func sayHello(w http.ResponseWriter, r *http.Request) { fmt.Fprintln(w, "Hello shanghai!") } func main() { http.HandleFunc("/", sayHello) err := http.ListenAndServe(":9090", nil) if err != nil { fmt.Printf("http server failed, err:%v\n", err) return } }
将上面的代码编译之后执行,打开你电脑上的浏览器在地址栏输入127.0.0.1:9090
回车
自定义Server
要管理服务端的行为,可以创建一个自定义的Server:
s := &http.Server{ Addr: ":8080", Handler: myHandler, ReadTimeout: 10 * time.Second, WriteTimeout: 10 * time.Second, MaxHeaderBytes: 1 << 20, } log.Fatal(s.ListenAndServe())
demo:
package main import ( "encoding/json" _"encoding/json" "fmt" "io/ioutil" "net/http" "net/url" "strings" ) var ( api = "http://xxxxx.com" token = "9adf92861" ) type Result struct { Code int `json:"code"` Msg string `json:"msg"` } type Resp struct { Code string `json:"code"` Msg string `json:"msg"` } func wechatUrlHandle(w http.ResponseWriter, r *http.Request){ // 获取链接地址 var wechatUrl string values := r.URL.Query() wechatUrl = values.Get("url") // 验证URL的正确性 targetUrl, err := url.ParseRequestURI(wechatUrl) if err != nil { fmt.Printf("parse url failed, err:%v\n", err) } fmt.Printf(fmt.Sprintf("url: %v", targetUrl)) // 拼接参数发起请求 data := fmt.Sprintf("token=%s&url=%s", token, targetUrl.String()) headers := "application/x-www-form-urlencoded" res, err := http.Post(api, headers, strings.NewReader(data)) if err != nil { fmt.Printf("post failed, err: %v\n", err) return } // 关闭请求资源 defer res.Body.Close() body, err := ioutil.ReadAll(res.Body) if err != nil{ fmt.Fprintf(w, fmt.Sprintf("get resp failed. err: %v\n", err)) return } var info Result var ress Resp w.Header().Set("Content-Type", "application/json") if err := json.Unmarshal(body, &info); err == nil { fmt.Println(info.Code, info.Msg) ress.Code = "200" ress.Msg = "Success" t, _ := json.Marshal(ress) w.Write(t) }else{ ress.Code = "200" ress.Msg = "failure" t, _ := json.Marshal(ress) fmt.Println("err: ", err) w.Write(t) } } func main() { http.HandleFunc("/wechat/url", wechatUrlHandle) err := http.ListenAndServe(":9090", nil) // 处理器参数一般未nil if err != nil { fmt.Printf("Http server failed. err: %v\n", err) return } }