Gin框架使用jwt

做个笔记，没有连数据库，没有存redis，只是demo

package main

import (
	"errors"
	"fmt"
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/dgrijalva/jwt-go/v4"
	"github.com/gin-gonic/gin"
)

type Users struct {
	Username string `json:"username"`
	Password string `json:"password"`
}

type CustomClaims struct {
	Users
	jwt.StandardClaims
}

var MySecret = []byte("密钥")

// 创建 Token
func GenToken(user Users) (string, error) {
	claim := CustomClaims{
		user,
		jwt.StandardClaims{
			ExpiresAt: jwt.At(time.Now().Add(time.Minute * 5)), //5分钟后过期
			Issuer:    "xx",                                    //签发人
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claim)
	return token.SignedString(MySecret)
}

// 解析 token
func ParseToken(tokenStr string) (*CustomClaims, error) {
	token, err := jwt.ParseWithClaims(tokenStr, &CustomClaims{}, func(token *jwt.Token) (interface{}, error) {
		return MySecret, nil
	})
	if err != nil {
		fmt.Println(" token parse err:", err)
		return nil, err
	}
	if claims, ok := token.Claims.(*CustomClaims); ok && token.Valid {
		return claims, nil
	}
	return nil, errors.New("invalid token")
}

// 刷新 Token
func RefreshToken(tokenStr string) (string, error) {
	jwt.TimeFunc = func() time.Time {
		return time.Unix(0, 0)
	}

	token, err := jwt.ParseWithClaims(tokenStr, &CustomClaims{}, func(token *jwt.Token) (interface{}, error) {
		return MySecret, nil
	})
	if err != nil {
		return "", err
	}
	if claims, ok := token.Claims.(*CustomClaims); ok && token.Valid {
		jwt.TimeFunc = time.Now
		claims.StandardClaims.ExpiresAt = jwt.At(time.Now().Add(time.Minute * 10))
		return GenToken(claims.Users)
	}
	return "", errors.New("Cloudn't handle this token")
}

// JWTAuth 中间件，检查token
func JWTAuth() gin.HandlerFunc {
	return func(ctx *gin.Context) {
		authHeader := ctx.Request.Header.Get("Authorization")
		if authHeader == "" {
			ctx.JSON(http.StatusOK, gin.H{
				"code": -1,
				"msg":  "无权限访问，请求未携带token",
			})
			ctx.Abort() //结束后续操作
			return
		}
		log.Print("token:", authHeader)

		//按空格拆分
		parts := strings.SplitN(authHeader, " ", 2)
		if !(len(parts) == 2 && parts[0] == "Bearer") {
			ctx.JSON(http.StatusOK, gin.H{
				"code": -1,
				"msg":  "请求头中auth格式有误",
			})
			ctx.Abort()
			return
		}

		//解析token包含的信息
		claims, err := ParseToken(parts[1])
		if err != nil {
			ctx.JSON(http.StatusOK, gin.H{
				"code": -1,
				"msg":  "无效的Token",
			})
			ctx.Abort()
			return
		}
		// 将当前请求的claims信息保存到请求的上下文c上
		ctx.Set("claims", claims)
		ctx.Next() // 后续的处理函数可以用过ctx.Get("claims")来获取当前请求的用户信息

	}
}

func LoginController(ctx *gin.Context) {
	username := ctx.Query("username")
	password := ctx.Query("password")
	if !(username == "admin" && password == "123456") {
		ctx.JSON(http.StatusOK, gin.H{
			"code": -1,
			"msg":  "用户名或密码错误",
		})
		return
	}
	user := Users{
		Username: "admin",
		Password: "123456",
	}
	//生成token
	token, err := GenToken(user)
	if err != nil {
		ctx.JSON(http.StatusOK, gin.H{
			"code": -1,
			"msg":  err,
		})
		return
	}

	ctx.JSON(http.StatusOK, gin.H{
		"code": 0,
		"msg":  "成功",
		"data": gin.H{"token": token},
	})

}

func UserListController(ctx *gin.Context) {
	ctx.JSON(http.StatusOK, gin.H{
		"code": 1,
		"msg":  "成功",
		"data": "[]",
	})
}

func main() {
	r := gin.Default()
	//路由
	r.GET("/login", LoginController)
	//使用中间件
	r.Use(JWTAuth())
	//获取列表数据
	r.GET("/list", UserListController)
	r.Run()
}