如何使用中间件

➜  go-gin-test tree -L 3 .├── go.mod├── go.sum├── hello├── mian.go└── routerex    └── router.go 

package midimport (	"github.com/gin-gonic/gin")func midAuth(c *gin.Context) {	//获取请求的ip地址	ip := c.ClientIP()	//如果请求地址来源不正确，那么阻止这个请求继续	if ip != "baidu.com" {		println("ip 地址不正确")                c.Abort()		return	}	// 处理请求	c.Next()} 

package routereximport (	"example.com/m/v2/routerex/mid"	"github.com/gin-gonic/gin")func InitRouter(g *gin.Engine) {	g1 := g.Group("g1")	//中间件	g1.Use(mid.MidAuth)	g1.GET("/hello1", func(c *gin.Context) {		c.JSON(200, gin.H{			"msg": "Hello g1",		})	})	g2 := g.Group("g2")	g2.GET("/hello2", func(c *gin.Context) {		c.JSON(200, gin.H{			"msg": "Hello g2",		})	})}

➜  go-gin-test go build -o hello➜  go-gin-test lsgo.mod   go.sum   hello    mian.go 

[GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.- using env:   export GIN_MODE=release- using code:  gin.SetMode(gin.ReleaseMode)[GIN-debug] GET    /g1/hello1                --> example.com/m/v2/routerex.InitRouter.func1 (4 handlers)[GIN-debug] GET    /g2/hello2                --> example.com/m/v2/routerex.InitRouter.func2 (3 handlers)[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default[GIN-debug] Listening and serving HTTP on :8080ip 地址不正确[GIN] 2021/04/06 - 17:00:38 | 200 |      61.658µs |             ::1 | GET      "/g1/hello1" 

func midCors(c *gin.Context) {  c.Header("Access-Control-Allow-Origin", c.Request.Header.Get("Origin"))  c.Header("Access-Control-Allow-Headers", "*")  c.Header("Access-Control-Allow-Methods", "*")  c.Header("Access-Control-Allow-Credentials", "true")  //放行所有OPTIONS方法  if c.Request.Method == "OPTIONS" {  	c.AbortWithStatus(http.StatusNoContent)  }  // 处理请求  c.Next()}  
  

name := c.Param("name")

//这个写法具有默认值firstname := c.DefaultQuery("firstname", "Guest") 

//无默认值message := c.PostForm("message")//有默认值nick := c.DefaultPostForm("nick", "anonymous") 

ids := c.QueryMap("ids")names := c.PostFormMap("names") 

form, _ := c.MultipartForm()files := form.File["upload[]"] 

//结构体j := J{}c.BindJSON(j)