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Gin introduction practice

2022-07-07 01:36:00 【hualaoshuan】

A summary of this article ：

1. Environment building 、 Thermal loading ;
2. The response data ;
3. Routing values ;
4. Routing grouping ：
5. Custom controller 、 Controller inheritance ;
6. Routing middleware ;
7. Customize Model;
8. Session obtain ：
9. Use GORM Operating the database ;

1. Environment building 、 Thermal loading ;

Chinese document ：https://gin-gonic.com/zh-cn/docs/quickstart/

#  download  gin 
cd ~/go/go-gin2
go get -u github.com/gin-gonic/gin

#  If you can't download , Try 
go env -w GO111MODULE=on
go env -w GOPROXY=https://mirrors.aliyun.com/goproxy/,direct

#  Project preparation （ Use  go.mod  Management project ）
cd ~/go/go-gin2/gindemo01
go mod init gindemo01

#  Compile the code after writing 
go run main.go

#  Third party hot loading 
#  file ：https://github.com/gravityblast/fresh
export GOPROXY=https://goproxy.io
go get -u github.com/pilu/fresh
# fresh  Put it in the project folder , Will generate... In the current directory  tmp  Catalog ：
fresh

file ~/go/go-gin2/gindemo01/main.go

package main

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

func main() {
    
	//  Create a default routing engine 
 	r := gin.Default()

 	//  Configure the routing 
 	r.GET("/", func(c *gin.Context) {
    
		c.String(http.StatusOK, " value ：%v", " Hello ")
	})

 	//  establish  web  service , Default  8080  port 
 	r.Run(":8001")
}

2. The response data ;

file ~/go/go-gin2/gindemo01/templates/index.html

<h1>{
   {.title}}</h1>

file ~/go/go-gin2/gindemo01/main.go

package main

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

type Article struct {
    
	Title string `json:"title"`
	Desc string `json:"desc"`
	Content string `json:"content"`
}

func main() {
    
	//  Create a default routing engine 
 	r := gin.Default()

	//  Configure template path 
	r.LoadHTMLGlob("templates/*")

 	//  Configure the routing 
 	r.GET("/", func(c *gin.Context) {
    
 		//  Return string 
		c.String(http.StatusOK, " value ：%v", " home page ")

		//  return json
 		c.JSON(http.StatusOK, map[string]interface{
    }{
    
 			"success" : true,
 			"msg": " complete ",
		})

		//  The built-in method returns  json
		c.JSON(http.StatusOK, gin.H{
    
			"success" : true,
			"msg": " complete 2",
		})

		//  Instantiate structure data 
		a := &Article{
    
			" title ",
			" Introduce ",
			" Content ",
		}
		c.JSON(http.StatusOK, a)
		// {"title":" title ","desc":" Introduce ","content":" Content "}

		//  return jsonp
		// http://localhost:8001/?callback=12
		c.JSONP(http.StatusOK, a)

		//  return  xml
		c.XML(http.StatusOK, gin.H{
    
			"success" : false,
			"msg": "xml",
		})

		//  Rendering  html
		c.HTML(http.StatusOK, "index.html", gin.H{
    
			"title" : " home page 1",
		})

	})

 	//  establish  web  service , Default  8080  port 
 	r.Run(":8001")
}

3. Routing values ;

file ~/go/go-gin2/gindemo01/main.go

package main

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

type UserInfo struct {
    
	Username string `json:"username" form:"username"`
	Passwd string `json:"passwd" form:"passwd"`
	Age string `json:"age" form:"age"`
}

func main() {
    
	//  Create a default routing engine 
 	r := gin.Default()

 	//  obtain  get  Pass value 
 	r.GET("/user", func(c *gin.Context) {
    
		username := c.Query("username")
		page := c.DefaultQuery("page","1")

		// http://localhost:8001/user?username=hua
		c.JSON(http.StatusOK, gin.H{
    
			"username" : username,
			"page": page,
		})
	})

 	//  obtain " Forms " Of  post  Pass value 
 	r.POST("/addUser", func(c *gin.Context) {
    
		username := c.PostForm("username")
		passwd := c.PostForm("passwd")
 		age := c.DefaultPostForm("age", "20")

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


	// Bind to structure 
	// http://localhost:8001/getUser?username=hua&passwd=123456
	r.GET("/getUser", func(c *gin.Context) {
    
		user := &UserInfo{
    }
		if err := c.ShouldBind(&user); err==nil {
    
			fmt.Printf("%#v", user) //  Print 
			c.JSON(http.StatusOK, user)
		} else {
    
			c.JSON(http.StatusOK, gin.H{
    
				"err": err.Error(),
			})
		}
	})

	r.POST("/addUser2", func(c *gin.Context) {
    
		user := &UserInfo{
    }
		if err := c.ShouldBind(&user); err==nil {
    
			fmt.Printf("%#v", user) //  Print 
			c.JSON(http.StatusOK, user)
		} else {
    
			c.JSON(http.StatusOK, gin.H{
    
				"err": err.Error(),
			})
		}
	})

 	//  Dynamic routing 
 	r.GET("/list/:cid", func(c *gin.Context) {
    
 		cid := c.Param("cid")
 		c.String(http.StatusOK, "%v", cid)
	})

 	//  establish  web  service , Default  8080  port 
 	r.Run(":8001")
}

4. Routing grouping ：

Insert picture description here

file ~/go/go-gin2/gindemo01/routers/defaultRouters.go

package routers

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

func DefaultRoutersInit (r *gin.Engine) {
    
	defaultRouters := r.Group("/")
	{
    
		defaultRouters.GET("/", func(c *gin.Context) {
    
			c.String(http.StatusOK, " home page ")
		})
	}
}

file ~/go/go-gin2/gindemo01/main.go

package main

import (
	"gindemo01/routers"
	"github.com/gin-gonic/gin"

)

func main() {
    
	//  Create a default routing engine 
	var r = gin.Default() 

	// Routing grouping 
	routers.DefaultRoutersInit(r)

 	//  establish  web  service , Default  8080  port 
 	r.Run(":8001")
}

5. Custom controller 、 Controller inheritance ;

Insert picture description here

file ~/go/go-gin2/gindemo01/controllers/baseControllers.go

package _default

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

type BaseController struct {
    

}

func (con BaseController) success (c *gin.Context) {
    
	c.String(http.StatusOK, "ok")
}

func (con BaseController) error (c *gin.Context) {
    
	c.String(http.StatusOK, "error")
}

file ~/go/go-gin2/gindemo01/controllers/userControllers.go

package _default

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

type UserController struct{
    
	BaseController	//  Controller inheritance 
}

func (con UserController) Index (c *gin.Context) {
    
	c.String(http.StatusOK, " User list ")
}

func (con UserController) Add (c *gin.Context) {
    
	c.String(http.StatusOK, " Add users ")
	con.success(c)
}

file ~/go/go-gin2/gindemo01/routers/defaultRouters.go

package routers

import (
	_default "gindemo01/controllers/default"
	"github.com/gin-gonic/gin"
	"net/http"
)

func DefaultRoutersInit (r *gin.Engine) {
    
	defaultRouters := r.Group("/")
	{
    
		defaultRouters.GET("/", func(c *gin.Context) {
    
			c.String(http.StatusOK, " home page ")
		})
		
		//  User list 
		// UserIndex()  Execution method , Without parentheses is the registration method 
		defaultRouters.GET("/user", _default.UserController{
    }.Index)

		//  Add users 
		defaultRouters.GET("/user/add", _default.UserController{
    }.Add)
	}
}

6. Routing middleware ;

Insert picture description here
If used in middleware goroutine：

When in middleware or handler Start a new goroutine when , Out of commission The original context c *gin.Context, Must use its read-only copy c.Copy()
file ~/go/go-gin2/gindemo01/middlewares/init.go

package middlewares

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

func InitMiddleware(c *gin.Context) {
    
	fmt.Println(time.Now())
	fmt.Println(c.Request.URL)

	//  Set up the data 
	c.Set("username", "zhang")

	//  Define the process statistics log 
	cc := c.Copy()
	go func() {
    
		time.Sleep(2 * time.Second)
		fmt.Println("Done! in path " + cc.Request.URL.Path)
	}()

}

file ~/go/go-gin2/gindemo01/routers/defaultRouters.go

package routers

import (
	"fmt"
	_default "gindemo01/controllers/default"
	"gindemo01/middlewares"
	"github.com/gin-gonic/gin"
	"net/http"
)

func DefaultRoutersInit (r *gin.Engine) {
    


	defaultRouters := r.Group("/")
	//  Configure global middleware 
	defaultRouters.Use(middlewares.InitMiddleware)
	{
    
		defaultRouters.GET("/", func(c *gin.Context) {
    
			//  Get the data of middleware 
			username, _ := c.Get("username")
			fmt.Println(username)

			//  Types of assertions 
			v, ok := username.(string)
			if ok == true {
    
				fmt.Println(" User name ：" +v)
			} else {
    
				fmt.Println(" Failed to get user ")
			}

			c.String(http.StatusOK, " home page ")
		})

		//  User list 
		// UserIndex()  Execution method , Without parentheses is the registration method 
		defaultRouters.GET("/user", _default.UserController{
    }.Index)

		//  Add users 
		defaultRouters.GET("/user/add", _default.UserController{
    }.Add)
	}
}

7. Customize Model;

About Model

If the application is very simple , Can be in Controller It handles common business logic . But if there is a function that you want to use in multiple controllers 、 Or reuse in multiple templates , The common functions can be extracted separately as a module （Model）.Model It is a process of gradual abstraction , Usually in Model Encapsulate some public methods to make it different Controller Use , You can also smash Model To deal with data
file ~/go/go-gin2/gindemo01/models/tools.go

package models

import (
	"time"
)

//  Time into date 
func UnixToTime(timestamp int) string {
    
	t := time.Unix(int64(timestamp), 0)
	return t.Format("2006-01-02 15:04:05")
}

call ：

time := models.UnixToTime(1653639435)
fmt.Println(" current time ："+time)

8. Session obtain ：

Gin Not provided session Related documents , Need a third party session Middleware to achieve

file ：https://github.com/gin-contrib/sessions
Installation mode ：go get github.com/gin-contrib/sessions
file ~/go/go-gin2/gindemo01/main.go

package main

import (
	"gindemo01/routers"
	"github.com/gin-contrib/sessions/redis"
	"github.com/gin-gonic/gin"
	"github.com/gin-contrib/sessions"
	"github.com/gin-contrib/sessions/cookie"
)

func main() {
    
	//  Create a default routing engine 
	var r = gin.Default()

	//  To configure  session  middleware 
	//  Create based on  cookie  Storage engine for ,secret  The parameter is the secret key used for encryption 
	store := cookie.NewStore([]byte("secret"))
	//  To configure  session  middleware ,store  Is the storage engine created earlier 
	r.Use(sessions.Sessions("mysession", store))

	// To configure  redis  Storage engine 
	store_redis, _ := redis.NewStore(10, "tcp", "localhost:6379", "", []byte("secret"))
	r.Use(sessions.Sessions("mysession_redis", store_redis))

	// Routing grouping 
	routers.DefaultRoutersInit(r)
	routers.ApiRoutersInit(r)

 	//  establish  web  service , Default  8080  port 
 	r.Run(":8001")
}

file ~/go/go-gin2/gindemo01/controllers/default/userController.go

package _default

import (
	"fmt"
	"gindemo01/models"
	"github.com/gin-contrib/sessions"
	"github.com/gin-gonic/gin"
	"net/http"
)

type UserController struct{
    
	BaseController	//  Controller inheritance 
}

func (con UserController) Index (c *gin.Context) {
    
	session := sessions.Default(c)
	//  Set expiration time, etc 
	session.Options(sessions.Options{
    
		MaxAge: 3600 * 6,
	})

	//  Set up  session
	session.Set("username1", "hua")
	session.Save()	// preservation 

	//  obtain  session
	username := session.Get("username1")
	c.String(http.StatusOK, "username=%v", username)

	time := models.UnixToTime(1653639435)
	fmt.Println(" current time ："+time)
	c.String(http.StatusOK, " User list ")
}

func (con UserController) Add (c *gin.Context) {
    
	c.String(http.StatusOK, " Add users ")
	con.success(c)
}

9. Use GORM Operating the database ;

brief introduction

GORM yes golang One of the orm frame ,orm It is through the syntax of the instance object , The technology of completing the operation of relational database 、 Is the abbreviation of object mapping
file ：https://gorm.io/zh_CN/docs/index.html
file ~/go/go-gin2/gindemo01/models/core.go

package models

import (
	"fmt"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

var DB *gorm.DB
var err error

func init () {
    
	//  Reference resources  https://github.com/go-sql-driver/mysql#dsn-data-source-name  For more details 
	dsn := "root:[email protected](127.0.0.1:3306)/test?charset=utf8mb4&parseTime=True&loc=Local"
	DB, err = gorm.Open(mysql.Open(dsn), &gorm.Config{
    })

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

file ~/go/go-gin2/gindemo01/models/user.go

package models

//  Structure initial capital 
//  Corresponding to the data table name , For example, the table is  user_info  Structure is defined as  UserInfo
//  By default, the table name is the plural form of the interface body 
type User struct {
    
	Id int
	Username string
	Age int
	Email string
	AddTime string
}

//  Modify the default table name of the structure , Configuration data sheet 
func (User) TableName() string {
    
	return "user"
}

file ~/go/go-gin2/gindemo01/controllers/default/userController.go

package _default

import (
	"gindemo01/models"
	"github.com/gin-gonic/gin"
	"net/http"
)

type UserController struct{
    
	BaseController	//  Controller inheritance 
}

func (con UserController) Index (c *gin.Context) {
    
	user := []models.User{
    }	//  Defining slices 
	//models.DB.Find(&user)
	models.DB.Where("age>20").Find(&user)
	c.JSON(http.StatusOK, gin.H{
    
		"result" : user,
	})
}

func (con UserController) Add (c *gin.Context) {
    
	c.String(http.StatusOK, " Add users ")
	con.success(c)
}

func (con UserController) Edit (c *gin.Context) {
    
	c.String(http.StatusOK, " Modify the user ")
}

func (con UserController) Delete (c *gin.Context) {
    
	c.String(http.StatusOK, " Delete user ")
}