Introduction to gin of go language, routing group settings, data parsing and binding, and gin middleware

gin introduction

Gin is a golang micro-framework with elegant encapsulation, friendly API, clear source code annotations, fast, flexible, and fault-tolerant convenience.
For golang, the dependency of the web framework is much smaller than that of Python, Java and the like. Its own net/http is simple enough, and its performance is also very good.
With the help of framework development, it can not only save a lot of time brought by commonly used packaging, but also help the team's coding style and form norms

gin install

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

gin route

func main()  {
    
    
	//创建路由
	r :=gin.Default()

	//绑定路由，执行的函数
	//gin.Context,封装了request和respose
	r.GET("/", func(c *gin.Context) {
    
    
		c.String(http.StatusOK,"hello hello")
	})
	r.Run(":8080")

}

Browse and enter: localhost:8080.

gin implements simple form submission

main.go

front-end page html

Gin implements file upload

The front-end page html

main.go

limits the file upload size and uploads multiple files

gin routing group

package main

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

func main()  {
    
    
	//创建路由
	r :=gin.Default()
	v1 := r.Group("/v1")
	{
    
    
		v1.GET("/login",login)
		v1.GET("/registry",registry)
	}
	v2 := r.Group("/v2")
	{
    
    
		v2.POST("/login",login)
		v2.POST("/registry",registry)
	}

	//绑定路由，执行的函数
	//gin.Context,封装了request和respose
	r.GET("/", func(c *gin.Context) {
    
    
		c.String(http.StatusOK,"hello hello")
	})
	r.Run(":8080")

}

func login(c *gin.Context)  {
    
    
	name := c.DefaultQuery("name","jack")
	c.String(200,fmt.Sprintf("login: hello %s\n",name))
}

func registry(c *gin.Context)  {
    
    
	name := c.DefaultQuery("name","jack")
	c.String(200,fmt.Sprintf("registry: hello %s\n",name))
}

Browser input:

gin routing principle

httprpter will construct a prefix tree of all routing rules

gin data analysis and binding

Structure:

type Login struct {
    
    

	User     string `form:"username" json:"user" url:"user" xml:"user" binding:"required"`
	Password string `form:"password" json:"password" url:"password" xml:"password" binding:"required"`
}

JSON data parsing and binding

r :=gin.Default()
	//绑定路由，执行的函数
	//gin.Context,封装了request和respose
	r.GET("/", func(c *gin.Context) {
    
    
		var json Login
		err := c.ShouldBindJSON(&json)
		if err != nil {
    
    
			//返回错误
			c.JSON(500,gin.H{
    
    "error":err.Error()})
		}
		fmt.Println(json.User,json.Password)
		c.String(200,fmt.Sprintf("login: user = %s,password = %s \n",json.User,json.Password))
		//c.JSON(200,json)
	})
	r.Run(":8080")

postman call:

form binding

r.GET("/", func(c *gin.Context) {
    
    
		var form Login
		if err :=c.Bind(&form); err != nil{
    
    
			//返回错误
			c.JSON(500,gin.H{
    
    "error":err.Error()})
		}
		c.JSON(http.StatusOK,gin.H{
    
    "ok":form})
	})
	r.Run(":8080")

Postman test results:

URL data parsing and binding

r.POST("/:user/:password", func(c *gin.Context) {
    
    
		var login Login
		//如果想用地址栏拼参数的方法，例如：http://localhost:8000/gin?user=zhangsan&password=123
		//可以用c.Query("key")来获取值
		err := c.ShouldBindUri(&login)
		if err != nil {
    
    
			//返回错误
			c.JSON(500,gin.H{
    
    "error":err.Error()})
		}
		fmt.Println(login.User,login.Password)
		//c.String(200,fmt.Sprintf("login: user = %s,password = %s \n",login.User,login.Password))
		//c.JSON(200,json)
		c.JSON(http.StatusOK,gin.H{
    
    "ok":login})
	})
	r.Run(":8080")

postman test:

gin middleware

global middleware

Console effect:

partial middleware