快速开发-基于gin的中间件web项目开发

一、概述

在 Gin 框架中，中间件（Middleware）是一种在处理 HTTP 请求之前或之后执行的函数。使用中间件可以方便地实现诸如身份验证（Auth）、日志记录、请求限流等功能。

二、编写中间件

// 中间件
func StartCost1(c *gin.Context) {log.Info("......start1......")start := time.Now()c.Next() //调用后续的处理函数// c.Abort() //阻止调用后续的处理函数cost := time.Since(start)log.Info("cost1:", cost)log.Info("......end1......")
}func StartCost2(c *gin.Context) {log.Info("......start2......")log.Info("......end2......")
}func authMiddleware(doCheck bool) gin.HandlerFunc {return func(ctx *gin.Context) {if doCheck {//检查用户信息ctx.Set("token", "20240814")// TODOlog.Info("检查用户登录信息")ctx.Next()} else {//不检查用户信息log.Error("不检查用户信息即可处理")ctx.Next()}}
}

三、使用中间件

func main() {r := gin.Default()r.Use(StartCost1, StartCost2, authMiddleware(true))r.LoadHTMLFiles("./index.html", "./home.html")r.GET("/web", func(c *gin.Context) {name := c.Query("query")c.JSON(http.StatusOK, gin.H{"name": name,})})r.GET("/login", func(ctx *gin.Context) {ctx.HTML(http.StatusOK, "index.html", nil)})r.GET("/home", func(ctx *gin.Context) {ctx.Request.URL.Path = "/b"r.HandleContext(ctx)})r.GET("/b", func(ctx *gin.Context) {log.Info("request /b GetLocalIP: " + GetLocalIP())ctx.Redirect(http.StatusMovedPermanently, GetLocalIP()+":9090/login")})r.POST("/login", func(ctx *gin.Context) {log.Info("request /login GetLocalIP: " + GetLocalIP())username := ctx.PostForm("username")password := ctx.PostForm("password")//从请求中获取携带的参数f, err := ctx.FormFile("file")if err != nil {ctx.JSON(http.StatusBadRequest, gin.H{"error": err,})} else {filePath := path.Join("./", f.Filename)ctx.SaveUploadedFile(f, filePath)ctx.HTML(http.StatusOK, "home.html", gin.H{"Name":     username,"Password": password,"Token":    ctx.GetString("token"),})}})r.Run(":9090")}

四、后端完整代码

package mainimport ("net""net/http""path""time""github.com/gin-gonic/gin"log "github.com/sirupsen/logrus"
)func GetLocalIP() string {ip := "127.0.0.1"addrs, err := net.InterfaceAddrs()if err != nil {return ip}for _, a := range addrs {if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {if ipnet.IP.To4() != nil {ip = ipnet.IP.String()break}}}return ip}// 中间件
func StartCost1(c *gin.Context) {log.Info("......start1......")start := time.Now()c.Next() //调用后续的处理函数// c.Abort() //阻止调用后续的处理函数cost := time.Since(start)log.Info("cost1:", cost)log.Info("......end1......")
}func StartCost2(c *gin.Context) {log.Info("......start2......")log.Info("......end2......")
}func authMiddleware(doCheck bool) gin.HandlerFunc {return func(ctx *gin.Context) {if doCheck {//检查用户信息ctx.Set("token", "20240814")// TODOlog.Info("检查用户登录信息")ctx.Next()} else {//不检查用户信息log.Error("不检查用户信息即可处理")ctx.Next()}}
}func main() {r := gin.Default()r.Use(StartCost1, StartCost2, authMiddleware(true))r.LoadHTMLFiles("./index.html", "./home.html")r.GET("/web", func(c *gin.Context) {name := c.Query("query")c.JSON(http.StatusOK, gin.H{"name": name,})})r.GET("/login", func(ctx *gin.Context) {ctx.HTML(http.StatusOK, "index.html", nil)})r.GET("/home", func(ctx *gin.Context) {ctx.Request.URL.Path = "/b"r.HandleContext(ctx)})r.GET("/b", func(ctx *gin.Context) {log.Info("request /b GetLocalIP: " + GetLocalIP())ctx.Redirect(http.StatusMovedPermanently, GetLocalIP()+":9090/login")})r.POST("/login", func(ctx *gin.Context) {log.Info("request /login GetLocalIP: " + GetLocalIP())username := ctx.PostForm("username")password := ctx.PostForm("password")//从请求中获取携带的参数f, err := ctx.FormFile("file")if err != nil {ctx.JSON(http.StatusBadRequest, gin.H{"error": err,})} else {filePath := path.Join("./", f.Filename)ctx.SaveUploadedFile(f, filePath)ctx.HTML(http.StatusOK, "home.html", gin.H{"Name":     username,"Password": password,"Token":    ctx.GetString("token"),})}})r.Run(":9090")}

五、前端页面

1、index.html

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Form</title>
</head><body><form action="/login" method="post" enctype="multipart/form-data"><div><label for="username">用户名：</label><input type="text" name="username" id="username" /></div><div><label for="password">密 码：</label><input type="text" name="password" id="password" /></div><div><label for="file">上传文件：</label><input type="file" name="file" id="file" /></div><div><input type="submit" value="提交"></div></form></body></html>

2、home.html

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>用户信息</title>
</head><body><h1> 您好，{{.Name}}</h1><span>密码：{{.Password}}</span><span>Token：{{.Token}}</span>
</body></html>