GolangHTTP参数解析实战教程

func handler(w http.ResponseWriter, r *http.Request) {
    name := r.FormValue("name")
    age := r.FormValue("age")
    fmt.Fprintf(w, "Name: %s, Age: %s", name, age)
}

err := r.ParseForm()
if err != nil {
    http.Error(w, "无法解析表单", http.StatusBadRequest)
    return
}
names := r.Form["name"] // 返回字符串切片

func postHandler(w http.ResponseWriter, r *http.Request) {
    if r.Method != "POST" {
        http.Error(w, "仅支持POST方法", http.StatusMethodNotAllowed)
        return
    }

    err := r.ParseForm()
    if err != nil {
        http.Error(w, "解析表单失败", http.StatusBadRequest)
        return
    }

    username := r.FormValue("username")
    password := r.FormValue("password")

    fmt.Fprintf(w, "用户: %s 提交了登录请求", username)
}

type User struct {
    Name  string `json:"name"`
    Email string `json:"email"`
}

func jsonHandler(w http.ResponseWriter, r *http.Request) {
    if r.Header.Get("Content-Type") != "application/json" {
        http.Error(w, "Content-Type需为application/json", http.StatusUnsupportedMediaType)
        return
    }

    var user User
    decoder := json.NewDecoder(r.Body)
    err := decoder.Decode(&user)
    if err != nil {
        http.Error(w, "JSON解析失败", http.StatusBadRequest)
        return
    }
    defer r.Body.Close()

    fmt.Fprintf(w, "收到用户: %s, 邮箱: %s", user.Name, user.Email)
}

func uploadHandler(w http.ResponseWriter, r *http.Request) {
    err := r.ParseMultipartForm(32 << 20) // 最大32MB
    if err != nil {
        http.Error(w, "解析 multipart 失败", http.StatusBadRequest)
        return
    }

    file, handler, err := r.FormFile("uploadfile")
    if err != nil {
        http.Error(w, "获取文件失败", http.StatusBadRequest)
        return
    }
    defer file.Close()

    // 保存文件或处理内容
    fmt.Fprintf(w, "上传文件名: %s, 大小: %d", handler.Filename, handler.Size)
}