[网络协议]Go net/http

go net/http

Go语言内置的net/http包性能十分的优秀，提供了HTTP客户端和服务端的实现。

HTTP客户端

程序在使用完response后必须关闭回复的主体。

自定义Client

管理HTTP客户端的头域、重定向策略和其他设置

func main(){
	client := http.Client{}
	request,_:=http.NewRequest("GET","https://www.baidu.com",nil)
	request.Header.Add("user-agent","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.60 Safari/537.36 Edg/100.0.1185.29")
	response, _ :=client.Do(request)
	fmt.Println(response.Request.Header)
	defer response.Body.Close()
	body, _ := ioutil.ReadAll(response.Body)
	fmt.Println(string(body))
}

自定义Transport

管理代理、TLS配置、keep-alive、压缩和其他设置

tr := &http.Transport{
	TLSClientConfig:    &tls.Config{RootCAs: pool},
	DisableCompression: true,
}
client := &http.Client{Transport: tr}
resp, err := client.Get("https://example.com")

http请求

GET请求

func main() {
	resp, err := http.Get("https://www.baidu.com/")
	if err != nil {
		fmt.Printf("get failed, err:%v\n", err)
		return
	}
	// 关闭response
	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
	}
	// 会触发反爬
	fmt.Print(string(body))
}

-------------------------------------------------------------
func main() {
	apiUrl := "http://www.baidu.com"
	// URL param
	data := url.Values{}
	data.Set("name", "小王子")
	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
	// https://www.baidu.com?age=18&name=%E5%B0%8F%E7%8E%8B%E5%AD%90
	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))
}

Post请求

func main() {
	url := "http://127.0.0.1:9090/post"
	// 表单数据
	//contentType := "application/x-www-form-urlencoded"
	//data := "name=小王子&age=18"
	// json
	contentType := "application/json"
	data := `{"name":"小王子","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))
}

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。

// http server

func sayHello(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintln(w, "Hello 沙河！")
}

func main() {
	http.HandleFunc("/", sayHello)
	err := http.ListenAndServe(":9090", nil)
	if err != nil {
		fmt.Printf("http server failed, err:%v\n", err)
		return
	}
}