go的gin跨域中间件

func CORSMiddleware() gin.HandlerFunc {

    return func(c *gin.Context) {

        c.Writer.Header().Set("Access-Control-Allow-Origin", "*")

        c.Writer.Header().Set("Access-Control-Allow-Credentials", "true")

        c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")

        c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET, PUT")

 

        if c.Request.Method == "OPTIONS" {

            c.AbortWithStatus(204)

            return

        }

 

        c.Next()

    }

}

 

 

package handler

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

const jwtCtxUidKey = "authedUserId"
const bearerLength = len("Bearer ")

func JwtMiddleware(c *gin.Context) {
   token, ok := c.GetQuery("_t")
   if !ok {
      hToken := c.GetHeader("Authorization")
      if len(hToken) < bearerLength {
         c.AbortWithStatusJSON(http.StatusPreconditionFailed, gin.H{"msg": "header Authorization has not Bearer token"})
         return
      }
      token = strings.TrimSpace(hToken[bearerLength:])
   }
   userId, err := model.JwtParseUser(token)
   if err != nil {
      c.AbortWithStatusJSON(http.StatusPreconditionFailed, gin.H{"msg": err.Error()})
      return
   }
   //store the user Model in the context
   c.Set(jwtCtxUidKey, userId)
   c.Next()
   // after request
}

func Cors() gin.HandlerFunc {
   return func(c *gin.Context) {
   method := c.Request.Method

    c.Header("Access-Control-Allow-Origin", "*")
    c.Header("Access-Control-Allow-Headers", "Content-Type,AccessToken,X-CSRF-Token, Authorization, Token")
    c.Header("Access-Control-Allow-Methods", "POST, GET, OPTIONS")
    c.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-    Headers, Content-Type")
    c.Header("Access-Control-Allow-Credentials", "true")

//放行所有OPTIONS方法
   if method == "OPTIONS" {
          c.AbortWithStatus(http.StatusNoContent)
}
// 处理请求
c.Next()
   }
}
3）在所有接口前增加router.Use(Cors())，放行所有的借口请求；

func Login_api_start() {
    router := gin.Default()
   //放行所有的请求
    router.Use(Cors())
   //用户登录接口
   router.POST("/userlogin", Userlogin)
   //新增支出接口
    router.GET("/sub",Subtraction)
//新增收入接口
   router.GET("/add",Add)
//获取到字典表
   router.GET("/getdict",Getdict)
//获取到支出信息
   router.GET("/getsub",Getsubtraction)
//获取到每个人支出和收入的占比
   router.GET("/statistics",Statistics)
   router.Run(":8081")
}