Go's gin framework learning

Frame installation

1、 Setting agent
In the download gin Before frame , We also need to configure go Public proxy image , The purpose is to solve github Unable to access or slow access , stay cmd Execute command in window ：

#  Here I set it to automatic mode ,on After I started the mode of, I couldn't execute it inexplicably gin The code download 
go env -w GO111MODULE=auto
#  Setting agent 
go env -w GOPROXY=https://goproxy.io,direct

2、 download gin frame

go get -u github.com/gin-gonic/gin

3、 establish demo project , function gin frame

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

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

	router.GET("/", func(context *gin.Context) {
    
		context.String(http.StatusOK, "HelloWorld")
	})

	router.Run(":3333")
}

4、 Lack of package error handling
Because of the Internet , Here and google Related packages are inaccessible , Need to download separately

..\github.com\go-playground\universal-translator\errors.go:7:2: cannot find package "github.com/go-playground/locales" in any of:
	C:\Program Files\Go\src\github.com\go-playground\locales (from $GOROOT)
	D:\go_work\src\github.com\go-playground\locales (from $GOPATH)
..\github.com\go-playground\validator\baked_in.go:23:2: cannot find package "github.com/leodido/go-urn" in any of:
	C:\Program Files\Go\src\github.com\leodido\go-urn (from $GOROOT)
	D:\go_work\src\github.com\leodido\go-urn (from $GOPATH)
..\github.com\gin-gonic\gin\logger.go:14:2: cannot find package "github.com/mattn/go-isatty" in any of:
	C:\Program Files\Go\src\github.com\mattn\go-isatty (from $GOROOT)
	D:\go_work\src\github.com\mattn\go-isatty (from $GOPATH)
..\github.com\gin-gonic\gin\binding\msgpack.go:15:2: cannot find package "github.com/ugorji/go/codec" in any of:
	C:\Program Files\Go\src\github.com\ugorji\go\codec (from $GOROOT)
	D:\go_work\src\github.com\ugorji\go\codec (from $GOPATH)
..\github.com\go-playground\validator\baked_in.go:20:2: cannot find package "golang.org/x/crypto/sha3" in any of:
	C:\Program Files\Go\src\golang.org\x\crypto\sha3 (from $GOROOT)
	D:\go_work\src\golang.org\x\crypto\sha3 (from $GOPATH)
..\github.com\gin-gonic\gin\gin.go:19:2: cannot find package "golang.org/x/net/http2" in any of:
	C:\Program Files\Go\src\golang.org\x\net\http2 (from $GOROOT)
	D:\go_work\src\golang.org\x\net\http2 (from $GOPATH)
..\github.com\gin-gonic\gin\gin.go:20:2: cannot find package "golang.org/x/net/http2/h2c" in any of:
	C:\Program Files\Go\src\golang.org\x\net\http2\h2c (from $GOROOT)
	D:\go_work\src\golang.org\x\net\http2\h2c (from $GOPATH)
..\github.com\go-playground\validator\baked_in.go:21:2: cannot find package "golang.org/x/text/language" in any of:
	C:\Program Files\Go\src\golang.org\x\text\language (from $GOROOT)
	D:\go_work\src\golang.org\x\text\language (from $GOPATH)
..\github.com\gin-gonic\gin\binding\protobuf.go:12:2: cannot find package "google.golang.org/protobuf/proto" in any of:
	C:\Program Files\Go\src\google.golang.org\protobuf\proto (from $GOROOT)
	D:\go_work\src\google.golang.org\protobuf\proto (from $GOPATH)

Compilation finished with exit code 1

1） stay GOPATH The directory src Under the table of contents , New folder google.golang.org, then cmd Window , Switch to the directory , Carry out orders ：
Notice that it's not github.com Under the table of contents , It is src Under the table of contents
D:\go_work\src\google.golang.org

git clone https://github.com/protocolbuffers/protobuf-go.git

When the download is complete , take protobuf-go Rename the directory to protobuf

2） Because of the Internet , Here and golang.org Related packages cannot be downloaded
stay GOPATH The directory src Under the table of contents , New folder golang.org, then cmd Window , Switch to the directory , Carry out orders ：
Notice that it's not github.com Under the table of contents , It is src Under the table of contents
D:\go_work\src\golang.org

git clone https://github.com/golang/tools.git

When the download is complete , take tools Rename the directory to x

3） Get into x Catalog , Go ahead with the order ：
D:\go_work\src\golang.org\x

git clone https://github.com/golang/crypto.git

4） Install as required github.com Missing package
1、 Get into D:\go_work\src\github.com\go-playground Under the table of contents

git clone https://github.com/go-playground/locales.git

2、 Get into D:\go_work\src\github.com\leodido Under the table of contents

git clone https://github.com/leodido/go-urn.git

3、 Get into D:\go_work\src\github.com\mattn Under the table of contents

git clone https://github.com/mattn/go-isatty.git

4、 Get into D:\go_work\src\github.com\ugorji Under the table of contents
Wrong presentation ：cannot find package “github.com/ugorji/go/codec” in any of:

git clone https://github.com/ugorji/go.git

5、 Get into D:\go_work\src\golang.org\x Under the table of contents , The lack of net package
Wrong presentation ：cannot find package “golang.org/x/net/http2” in any of:
cannot find package “golang.org/x/net/http2/h2c” in any of:

git clone https://github.com/golang/net.git

6、 Get into D:\go_work\src\golang.org\x Under the table of contents , The lack of text package
Wrong presentation ：cannot find package “golang.org/x/text/language” in any of:
cannot find package “golang.org/x/text/secure/bidirule” in any of:

git clone https://github.com/golang/text.git

Successfully started the service
visit ：http://127.0.0.1:3333/

Use of simple routing

gin Your route comes from httprouter library , therefore httprouter Functions gin Also has the

actual combat
Code ：

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
    
	// initialization router
	router := gin.Default()
	// Define the path , Use a colon : Instead of variables 
	router.GET("/user/:name/:age", func(context *gin.Context) {
    
		// obtain name value 
		name := context.Param("name")
		age := context.Param("age")
		message := name + " is " + age
		// Return value 
		context.String(http.StatusOK, "hello %s", message)
	})

	router.Run()
}

visit
http://127.0.0.1:8080/user/user11/18

Get Request to use

1、context.DefaultQuery Set the default value when the value cannot be obtained
2、context.Query Direct value

Code

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
    
	// initialization router
	router := gin.Default()
	// Define the path 
	router.GET("/user/", func(context *gin.Context) {
    
		// obtain name value 
		name := context.DefaultQuery("name"," The default value is ")
		age := context.Query("age")
		message := name + " is " + age
		// Return value 
		context.String(http.StatusOK, "hello %s", message)
	})

	router.Run()
}

visit
http://127.0.0.1:8080/user/?name=user1&age=18

Post Request to use

Common scenes
1、application/json （request Sent in json data , use post Mode sending Content-type use application/json）
2、application/x-www-form-urlencode （ Common form submission , hold query_string Put the content of body in vivo , Also need to urlencode）
3、application/xml （http As a transport protocol ,xml As a coding method, remote call specification ）
4、multipart/form-data（ File transfer ）

Code

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
    
	// initialization router
	router := gin.Default()
	// Definition POST Method path 
	router.POST("/form_post", func(context *gin.Context) {
    
		// Get the value passed 
		name := context.PostForm("name")
		age := context.DefaultPostForm("age","10")
		// With JSON Format return 
		context.JSON(http.StatusOK, gin.H{
    "status":gin.H{
    "status_code":http.StatusOK,"status":"ok"},"name":name,"age":age})
	})

	router.Run()
}

Access and return results
D:\go_work\src>curl -X POST http://127.0.0.1:8080/form_post -H “application/x-www-form-urlencode” -d “name=user123&age=18”

{“age”:“18”,“name”:“user123”,“status”:{“status”:“ok”,“status_code”:200}}

File upload use

Use post Method , Type used multipart/form-data

Code

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
    
	// initialization router
	router := gin.Default()
	// Definition POST Method path 
	router.POST("/upload", func(context *gin.Context) {
    
		// Get the value passed 
		name := context.PostForm("name") // according to name Property to get the alias 
		file, err := context.FormFile("upload")
		if err != nil {
    
			context.JSON(http.StatusBadRequest, gin.H{
    "status": gin.H{
    "status_code": http.StatusBadRequest, "msg": "a bad request"}})
			return
		}
		filename := file.Filename
		if err := context.SaveUploadedFile(file, filename); err != nil {
    
			context.JSON(http.StatusBadRequest, gin.H{
    "status": gin.H{
    "status_code": http.StatusBadRequest, "msg": "upload file err:" + err.Error()}})
			return
		}
		// With JSON Format return 
		context.JSON(http.StatusOK, gin.H{
    "status": gin.H{
    "status_code": http.StatusOK, "status": "ok"}, "name":name,"filename": filename})
	})

	router.Run()
}

Access and return results

Multi route access

http://localhost:8080/v1/submit
http://localhost:8080/v1/login
http://localhost:8080/v1/read

http://localhost:8080/v2/submit
http://localhost:8080/v2/login
http://localhost:8080/v2/read

v1 := router.Group(“v1”)
{
v1.Get(“/login”, Method name )
}

Code

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
)

func login(ctx *gin.Context) {
    
	fmt.Println("this is a login method")
}

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

	v1 := router.Group("v1")
	{
    
		v1.GET("/login", login)
	}

	v2 := router.Group("v2")
	{
    
		v2.GET("/login", login)
	}

	router.Run()
}

visit
http://127.0.0.1:8080/v1/login
http://127.0.0.1:8080/v2/login