Golang的http編程

文章目錄

1. 概述

我們簡單的描述一下什麼是web服務的工作方式,通常一個客戶端(客戶端可以是瀏覽器或者其他任何能發送http請求得工具)請求一個URL(uniform resource locator ) ,如果這個url是域名那麼首先會去請求DNS(Domain Name System) 獲取域名對應的真實IP(InternetProtocol) ,通過IP找到對應的服務器,並與服務器建立TCP(Transmission Control Protocol) 連接,客戶端向服務器發送 HTTP Request 數據包,服務服務器處理該請求後,向客戶端響應HTTP response 包, 客戶端接受這個響應,並做響應的處理,等全部接受之後,就斷開這個TCP連接

HTPP協議就是超文本傳輸協議(HyperText Transfer Protocol ) HTTP協議承載於TCP協議之上的,也可以說HTTP協議的基礎是TCP協議

HTTPS協議超文本傳輸安全協議(Hypertext Transfer Protocol Secure) 就是HTTP協議的安全版,在HTTP的協議基礎上加入了TLS(Transport Layer Security 安全傳輸層協議)或者SSL(Secure Sockets Layer 安全套接層)協議層

通過Go語言來編寫一個http服務器非常簡單,同時通過Go語言發送http請求也很簡單,我們使用 net/http 包就能實現

2. http服務端

package main

import (
	"fmt"
	"log"
	"net/http"
)


func defaultFunc(w http.ResponseWriter, r *http.Request) {
	fmt.Println("client connect success ", r.RemoteAddr)
	// 以json格式響應給客戶端
    fmt.Fprintf(w, "%v\n", "welcome to user")

}
func main() {
	http.HandleFunc("/", defaultFunc)
	if err := http.ListenAndServe(":8080", nil); err != nil {
		log.Fatal("ListenAndServer: ", err)
	}
}

3. https服務端

首先在本地構建https證書(windows10環境)

執行指令1

$ openssl genrsa -out server.key 2048
Generating RSA private key, 2048 bit long modulus (2 primes)
..................+++++
........+++++
e is 65537 (0x010001)

執行指令2

$ openssl req -new -x509 -key server.key -out server.crt -days 365
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:CN
State or Province Name (full name) [Some-State]:demo1
Locality Name (eg, city) []:Beijing
Organization Name (eg, company) [Internet Widgits Pty Ltd]:PANG
Organizational Unit Name (eg, section) []:
Common Name (e.g. server FQDN or YOUR name) []:localhost
Email Address []:

package main

import (
	"fmt"
	"net/http"
)

func MyFunc(w http.ResponseWriter, r *http.Request) {
	fmt.Println(r.Method, r.RemoteAddr)
	fmt.Fprintf(w, "%s", "https request")
}
func main() {
	http.HandleFunc("/", MyFunc)
	cf := "E:/Go/src/GoNote/chapter9/demo12/main/server.crt"
	ck := "E:/Go/src/GoNote/chapter9/demo12/main/server.key"
    // 監聽8081端口
	http.ListenAndServeTLS(":8081", cf, ck, nil)
}

3. http客戶端發送請求

發送http請求,請求方式有POST ,GET ,PUT, DELETE等

編寫一個http web服務端用來處理客戶端的請求

httpServer.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"time"
)

type responseToClient struct {
	Code    int               `json:"code"`
	Message string            `json:"message"`
	Data    map[string]string `json:"data"`
}

func defaultFunc(w http.ResponseWriter, r *http.Request) {
	var dataForm map[string][]string
	// 標識一個客戶端的連接
	fmt.Println("client connect success ", r.RemoteAddr)
	// 獲取地址欄內容
	fmt.Println(r.Method, r.RequestURI)
	// 獲取請求頭內容
	for k, v := range r.Header {
		fmt.Println(k, v[0])
	}
	data := make(map[string]string)
	if err := r.ParseForm(); err == nil {
		if r.Form != nil {
			dataForm = r.Form
		}
	}
	// 讀取客戶端的內容
	buf := make([]byte, 2048)
	n, _ := r.Body.Read(buf)
	// 獲取請求體中的內容
	fmt.Println("receive data from body", string(buf[:n]))

	if r.Method == "GET" {
		// 解析參數
		r.ParseForm()
		for k, v := range r.Form {
			data[k] = v[0]
		}
	}
	// 處理客戶端發送的POST請求和PUT請求
	if r.Method == "POST" || r.Method == "PUT" {
		ct, ok := r.Header["Content-Type"]
		if ok {
			// 如果是json數據根據請求頭判斷
			if ct[0] == "application/json" {
				json.Unmarshal(buf[:n], &data)
			}
			// 如果是POST表單數據
			if ct[0] == "application/x-www-form-urlencoded" {
				if dataForm != nil {
					for k, v := range dataForm {
						data[k] = v[0]
					}
				}
			}
		}
	}
	// 處理客戶端的DELETE請求
	// 記錄當前時間 `2006-01-02 15:04:05` 是指的格式格式
	data["time"] = time.Now().Format("2006-01-02 15:04:05")
	m := responseToClient{200, "success", data}
	mjson, e := json.Marshal(m)
	if e != nil {
		fmt.Println(e)
	}
	// 以json格式響應給客戶端
	fmt.Fprintf(w, "%v\n", string(mjson))

}
func main() {
	http.HandleFunc("/", defaultFunc)
	if err := http.ListenAndServe(":8080", nil); err != nil {
		log.Fatal("ListenAndServer: ", err)
	}
}

編寫一能發送http請求的客戶端包含 post,get,put,delete請求

httpClients.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"strconv"
	"strings"
)

const BC = "http://127.0.0.1:8080/"

// 發送一個簡單的http GET請求
func httpSimpleGet() {
	resp, err := http.Get(BC + "index?aa=AA&bb=BB")
	if err != nil {
		log.Println(err)
	}
	defer resp.Body.Close()
	// 獲取響應內容
	resultByte, _ := ioutil.ReadAll(resp.Body)
	fmt.Println(string(resultByte))
}

// 設置請求頭和請求參數的Get請求
func httpGet() {
	client := &http.Client{}
	request, err := http.NewRequest("GET", BC, nil)
	if err != nil {
		log.Println(err)
	}
	// 在請求頭中添加自定義數據
	request.Header.Add("company", "PG")
	request.Header.Add("appkey", "Test_0001")
	// 添加請求參數
	params := request.URL.Query()
	params.Add("name", "pg")
	params.Add("addr", "chain")
	request.URL.RawQuery = params.Encode()
	// 發送http請求,請求成功,獲取響應
	resp, err := client.Do(request)
	if err != nil {
		log.Println(err)
	}
	// 獲取所有的響應內容
	result, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Println(err)
	}
	// 打印響應的內容
	fmt.Println(string(result))
}

// http POST請求,併發送json數據
func httpPostJson() {
	// post json 數據應用比較廣泛
	// 發送json數據,我們一般是用使用map或者結構體存儲數據
	// 然後轉換成json數據
	// 然後轉換成byte數據,放在發送的body中一起發送
	// 我們模擬一下這個過程
	var std map[string]string = map[string]string{"work": "programmer", "skills": "golang", "addr": "北京"}
	data, err := json.Marshal(std)
	if err != nil {
		log.Println(err)
	}
	body := bytes.NewBuffer([]byte(data))
	req, err := http.NewRequest("POST", BC, body)
	if err != nil {
		log.Println(err)
	}
	// 設置請求頭
	req.Header.Add("Accept", "application/json")
	req.Header.Add("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	defer resp.Body.Close()
	if err != nil {
		log.Println(err)
	}
	result, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Println(err)
	}
	fmt.Println(string(result))
}

// 模擬post發送表單數據
func HttpPosForm() {
	formData := url.Values{}
	formData.Set("userName", "admin")
	formData.Set("userPwd", "admin123456")
	req, err := http.NewRequest("POST", BC, strings.NewReader(formData.Encode()))
	if err != nil {
		log.Println(err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.Header.Set("Content-Length", strconv.Itoa(len(formData.Encode())))
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Println(err)
	}
	defer resp.Body.Close()
	result, err := ioutil.ReadAll(resp.Body)
	fmt.Println(string(result))

}

// 模擬客戶端發送PUT請求
func HttpPut() {
	// 發送PUT請求和POST請求類似都可以發送json和form數據
	std := map[string]string{"method": "PUT"}
	data, err := json.Marshal(std)
	if err != nil {
		log.Println(err)
	}
	body := bytes.NewBuffer([]byte(data))
	req, err := http.NewRequest("PUT", BC, body)
	if err != nil {
		log.Println(err)
	}
	req.Header.Add("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	defer resp.Body.Close()
	if err != nil {
		log.Println(err)
	}
	result, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Println(err)
	}
	fmt.Println(string(result))
}

//模擬客戶端發送DELETE請求
func HttpDelete() {
	req, err := http.NewRequest("DELETE", BC, nil)
	if err != nil {
		log.Println(err)
	}
	// 添加請求參數 與發送get請求類似
	params := req.URL.Query()
	params.Add("user", "pahnaskdjalsdklasd")
	req.URL.RawQuery = params.Encode()
	// 發送http請求,請求成功,獲取響應
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Println(err)
	}
	// 獲取所有的響應內容
	result, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Println(err)
	}
	// 打印響應的內容
	fmt.Println(string(result))
}
func main() {

	//httpSimpleGet()
	//httpGet()
	//httpPostJson()
	//HttpPosForm()
	//HttpPut()
	HttpDelete()
}

Golang的http編程

文章目錄

1. 概述

2. http服務端

3. https服務端

3. http客戶端發送請求

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