Go Web 开发核心理论与实战指南 | 极客日志

Go Web 开发核心理论与实战指南 | 极客日志

import (
	_ "github.com/go-sql-driver/mysql"
	"github.com/jmoiron/sqlx"
)

// 核心两步：打开连接并 Ping 测试
DB, err := sqlx.Open("mysql", "root:1234@tcp(localhost:3306)/goweb?parseTime=true&loc=Local")
if err != nil {
	log.Fatal(err)
}
err = DB.Ping()

// 定义语句
queryCreate := "insert into user (id,name) values (?,?)"
queryDelete := "delete from user where id =?"
queryUpdate := "update user set name=? where id=?"
queryQuery := "select * from user"

// 执行增删改
_, err := DB.Exec(queryCreate, 1, "白小纯") // 增
_, err = DB.Exec(queryDelete, 1)            // 删
_, err = DB.Exec(queryUpdate, "夜藏", 1)     // 改

// 执行查
rows, err := DB.Query(queryQuery)
for rows.Next() {
	var id int
	var name string
	err = rows.Scan(&id, &name)
	if err != nil {
		break
	}
}

func serv(w http.ResponseWriter, r *http.Request) {
	// 设置 Cookie
	cookie := &http.Cookie{
		Name:  "session_id",
		Value: "cookie",
		Expires: time.Now().Add(time.Second),
	}
	http.SetCookie(w, cookie)

	// 获取单个 Cookie
	c, _ := r.Cookie("session_id")
	fmt.Fprintln(w, c.Name, c.Value, c.Expires)

	// 循环获取所有 Cookie
	cs := r.Cookies()
	for _, co := range cs {
		fmt.Fprintln(w, co.Name, co.Value)
	}
}

// 后端界面渲染
func temp(w http.ResponseWriter, r *http.Request) {
	add := template.FuncMap{"add": Add}
	t := template.New("index").Funcs(add)
	t, _ = t.ParseFiles("new_add")
	t.Execute(w, nil)
}

<form action="/upload" enctype="multipart/form-data" method="post">
	上传照片：<input type="file" name="photo">
</form>

func upload(w http.ResponseWriter, r *http.Request) {
	f, _, _ := r.FormFile("photo")
	b, _ := io.ReadAll(f)
	// 使用 os.WriteFile 替代废弃的 ioutil
	err := os.WriteFile("/tmp/photo.jpg", b, 0777)
	if err != nil {
		fmt.Println("上传失败")
	}
}

<a href="/download?filename=file.png">点击我下载</a>

func download(w http.ResponseWriter, r *http.Request) {
	name := r.FormValue("filename")
	data, _ := os.ReadFile("./files/" + name)
	
	h := w.Header()
	h.Set("Content-Type", "application/octet-stream")
	h.Set("Content-Disposition", "attachment; filename=photo")
	w.Write(data)
}

type myStruct struct{}

func (m myStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	// 处理逻辑
}

func main() {
	s := http.Server{
		Addr:    "localhost:8888",
		Handler: myStruct{},
	}
	s.ListenAndServe()
}

func Test(w http.ResponseWriter, r *http.Request) {}

func main() {
	http.HandleFunc("/url", Test)
	s := http.Server{Addr: "localhost:8888"}
	s.ListenAndServe()
}