Go-微框架Gin简单使用

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---

框架的使用对于敏捷开发来说是非常重要的，虽然有不要重复造轮子的老话，但是在使用框架的同时一定要学习人家的思想与实现方式，免得发生没了框架就不会写代码的境地。
Gin的github地址：
https://github.com/gin-gonic/gin
中文文档地址：
https://gin-gonic.com/zh-cn/docs/

学习例子

1 hello word

import (
    "gopkg.in/gin-gonic/gin.v1"
    "net/http"
)

func main(){

    router := gin.Default()

    router.GET("/", func(c *gin.Context) {
        c.String(http.StatusOK, "Hello World")
    })
    router.Run(":8000")
}

2 GET请求

func main(){
    router := gin.Default()

    router.GET("/user/:name", func(c *gin.Context) {
        name := c.Param("name")
        c.String(http.StatusOK, "Hello %s", name)
    })
}

3简单的post请求

router.POST("/form_post", func(c *gin.Context) {
		message := c.PostForm("message")
		nick := c.DefaultPostForm("nick", "anonymous")

		c.JSON(http.StatusOK, gin.H{
			"status": gin.H{
				"status_code": http.StatusOK,
				"status":      "ok",
			},
			"message": message,
			"nick":    nick,
		})
	})

4 PUT 请求

router.PUT("/post", func(c *gin.Context) {
	id := c.Query("id")
	page := c.DefaultQuery("page", "0")
	name := c.PostForm("name")
	message := c.PostForm("message")
	fmt.Printf("id: %s; page: %s; name: %s; message: %s \n", id, page, name, message)
	c.JSON(http.StatusOK, gin.H{
		"status_code": http.StatusOK,
	})
})

5上传文件

router.POST("/upload", func(c *gin.Context) {
	name := c.PostForm("name")
	fmt.Println(name)
	file, header, err := c.Request.FormFile("upload")
	if err != nil {
		c.String(http.StatusBadRequest, "Bad request")
		return
	}
	filename := header.Filename

	fmt.Println(file, err, filename)

	c.String(http.StatusCreated, "upload successful")
})

6 批量上传文件

router.POST("/multi/upload", func(c *gin.Context) {
	err := c.Request.ParseMultipartForm(200000)
	if err != nil {
		log.Fatal(err)
	}

	formdata := c.Request.MultipartForm
	files := formdata.File["upload"]
	for i := range files {
		file, err := files[i].Open()
		filename := files[i].Filename
		fmt.Println(file, err, filename)
		defer file.Close()
		if err != nil {
			log.Fatal(err)
		}
		c.String(http.StatusCreated, "upload successful")

	}

})

####7 c.HTML模板

router.LoadHTMLGlob("G:\\GO\\src\\go-study\\src\\templates/*")
router.GET("/upload", func(c *gin.Context) {
	c.HTML(http.StatusOK, "upload.html", gin.H{})
})

####8 c.BindJSON和c.BindWith

router.POST("/login", func(c *gin.Context) {
	var user User
	var err error
	contentType := c.Request.Header.Get("Content-Type")

	switch contentType {
	case "application/json":
		err = c.BindJSON(&user)
	case "application/x-www-form-urlencoded":
		err = c.BindWith(&user, binding.Form)
	}

	if err != nil {
		fmt.Println(err)
		log.Fatal(err)
	}

	c.JSON(http.StatusOK, gin.H{
		"user":   user.Username,
		"passwd": user.Passwd,
		"age":    user.Age,
	})

})

9 自动Bind

router.POST("/login", func(c *gin.Context) {
	var user User

	err := c.Bind(&user)
	if err != nil {
		fmt.Println(err)
		log.Fatal(err)
	}

	c.JSON(http.StatusOK, gin.H{
		"username": user.Username,
		"passwd":   user.Passwd,
		"age":      user.Age,
	})

})

10 c.JSON与c.XML

router.GET("/render", func(c *gin.Context) {
	contentType := c.DefaultQuery("content_type", "json")
	if contentType == "json" {
		c.JSON(http.StatusOK, gin.H{
			"user":   "rsj217",
			"passwd": "123",
		})
	} else if contentType == "xml" {
		c.XML(http.StatusOK, gin.H{
			"user":   "rsj217",
			"passwd": "123",
		})
	}

})

11 重定向

//重定向
router.GET("/redict/google", func(c *gin.Context) {
	c.Redirect(http.StatusMovedPermanently, "https://google.com")
})

12 路由分组

//分组路由
	v1 := router.Group("/v1")

	v1.GET("/login", func(c *gin.Context) {
		c.String(http.StatusOK, "v1 login")
	})

	v2 := router.Group("/v2")

	v2.GET("/login", func(c *gin.Context) {
		c.String(http.StatusOK, "v2 login")
	})

13 middleware中间件

	//全局中间件
	router.Use(MiddleWare())
	{
		router.GET("/middleware", func(c *gin.Context) {
			request := c.MustGet("request").(string)
			req, _ := c.Get("request")
			c.JSON(http.StatusOK, gin.H{
				"middile_request": request,
				"request":         req,
			})
		})
	}
	//单个路由中间件
	router.GET("/before", MiddleWare(), func(c *gin.Context) {
		request := c.MustGet("request").(string)
		c.JSON(http.StatusOK, gin.H{
			"middile_request": request,
		})
	})
	//鉴权中间件
	router.GET("/auth/signin", func(c *gin.Context) {
		cookie := &http.Cookie{
			Name:     "session_id",
			Value:    "123",
			Path:     "/",
			HttpOnly: true,
		}
		http.SetCookie(c.Writer, cookie)
		c.String(http.StatusOK, "Login successful")
	})

	router.GET("/home", AuthMiddleWare(), func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"data": "home"})
	})
//鉴权中间件
func AuthMiddleWare() gin.HandlerFunc {
	return func(c *gin.Context) {
		if cookie, err := c.Request.Cookie("session_id"); err == nil {
			value := cookie.Value
			fmt.Println(value)
			if value == "123" {
				c.Next()
				return
			}
		}
		c.JSON(http.StatusUnauthorized, gin.H{
			"error": "Unauthorized",
		})
		c.Abort()
		return
	}
}

//全局中间件
func MiddleWare() gin.HandlerFunc {
	return func(c *gin.Context) {
		fmt.Println("before middleware")
		c.Set("request", "clinet_request")
		c.Next()
		fmt.Println("before middleware")
	}
}

14 异步协程

//异步协程
router.GET("/sync", func(c *gin.Context) {
	time.Sleep(5 * time.Second)
	log.Println("Done! in path" + c.Request.URL.Path)
})

15 自定义router

	//自定义router
	router.GET("/async", func(c *gin.Context) {
		cCp := c.Copy()
		go func() {
			time.Sleep(5 * time.Second)
			log.Println("Done! in path" + cCp.Request.URL.Path)
		}()
	})
	s := &http.Server{
		Addr:           ":8000",
		Handler:        router,
		ReadTimeout:    10 * time.Second,
		WriteTimeout:   10 * time.Second,
		MaxHeaderBytes: 1 << 20,
	}
	s.ListenAndServe()
	//_ = router.Run(":8000")
}