1. 渲染 XML/JSON/YAML/ProtoBuf

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

	// gin.H is a shortcut for map[string]interface{}
	r.GET("/someJSON", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"message": "hello", "status": http.StatusOK})
	})

	r.GET("/moreJSON", func(c *gin.Context) {
		// You also can use a struct
		var msg struct {
			Name    string `json:"user"`
			Message string
			Number  int
		}
		msg.Name = "wohu"
		msg.Message = "hello"
		msg.Number = 123
		// Note that msg.Name becomes "user" in the JSON
		// Will output  :   {"user": "wohu", "Message": "hello", "Number": 123}
		c.JSON(http.StatusOK, msg)
	})

	r.GET("/someXML", func(c *gin.Context) {
		c.XML(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})
	})

	r.GET("/someYAML", func(c *gin.Context) {
		c.YAML(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})
	})

	r.GET("/someProtoBuf", func(c *gin.Context) {
		reps := []int64{int64(1), int64(2)}
		label := "test"
		// The specific definition of protobuf is written in the testdata/protoexample file.
		data := &protoexample.Test{
			Label: &label,
			Reps:  reps,
		}
		// Note that data becomes binary data in the response
		// Will output protoexample.Test protobuf serialized data
		c.ProtoBuf(http.StatusOK, data)
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

输出结果：

wohu@wohu-pc:~$ curl  http://127.0.0.1:8080/someJSON
{"message":"hello","status":200}

wohu@wohu-pc:~$ curl  http://127.0.0.1:8080/moreJSON
{"user":"wohu","Message":"hello","Number":123}

wohu@wohu-pc:~$ curl  http://127.0.0.1:8080/someXML
<map><message>hey</message><status>200</status></map>

wohu@wohu-pc:~$ curl  http://127.0.0.1:8080/someYAML
message: hey
status: 200
wohu@wohu-pc:~$

2. 上传单个文件

The filename is always optional and must not be used blindly by the application: path information should be stripped, and conversion to the server file system rules should be done.

func main() {
	router := gin.Default()
	// Set a lower memory limit for multipart forms (default is 32 MiB)
	router.MaxMultipartMemory = 8 << 20  // 8 MiB
	router.POST("/upload", func(c *gin.Context) {
		// single file
		file, _ := c.FormFile("file")
		log.Println(file.Filename)

		// Upload the file to specific dst.
        dst := "test.png"
		c.SaveUploadedFile(file, dst)

		c.String(http.StatusOK, fmt.Sprintf("'%s' uploaded!", file.Filename))
	})
	router.Run(":8080")
}

使用方法

curl -X POST http://localhost:8080/upload \
  -F "file=@/Users/appleboy/test.zip" \
  -H "Content-Type: multipart/form-data"

3. 上传多个文件

func main() {
	router := gin.Default()
	// Set a lower memory limit for multipart forms (default is 32 MiB)
	router.MaxMultipartMemory = 8 << 20  // 8 MiB
	router.POST("/upload", func(c *gin.Context) {
		// Multipart form
		form, _ := c.MultipartForm()
		files := form.File["upload[]"]

		for _, file := range files {
			log.Println(file.Filename)

			// Upload the file to specific dst.
			c.SaveUploadedFile(file, dst)
		}
		c.String(http.StatusOK, fmt.Sprintf("%d files uploaded!", len(files)))
	})
	router.Run(":8080")
}

使用方法：

curl -X POST http://localhost:8080/upload \
  -F "upload[]=@/Users/appleboy/test1.zip" \
  -F "upload[]=@/Users/appleboy/test2.zip" \
  -H "Content-Type: multipart/form-data"

4. 替换 JSON 编译

Gin使用 encoding/json作为默认的 json包，但可以通过从其他标签构建来改变它。

• jsoniter

$ go build -tags=jsoniter .

• go_json

$ go build -tags=go_json .

5. 无 MsgPack 渲染功能编译

Gin默认启用 MsgPack渲染功能。但可以通过指定 nomsgpack build标签来禁用这一功能。

$ go build -tags=nomsgpack .

这对于减少可执行文件的二进制大小很有用。