gin框架学习-中间件

所有网络请求,都可以使用中间件进行增强处理, 过滤处理等

跨域处理:

//跨域访问: cross origin resource share
func Cors()gin.HandlerFunc  {
	return func (context *gin.Context){
		method := context.Request.Method
		origin := context.Request.Header.Get("Origin")
		var headerKeys []string
		for key, _ := range context.Request.Header{
			headerKeys = append(headerKeys, key)
		}
		headerStr := strings.Join(headerKeys, ",")
		if headerStr != ""{
			headerStr = fmt.Sprintf("access-control-allow-origin, access-control-allow-headers, %s", headerStr)
		} else{
			headerStr = "access-control-allow-origin, access-control-allow-headers"
		}

		if origin != ""{
			context.Writer.Header().Set("Access-Control-Allow-Origin", "*")
			context.Header("Access-Control-Allow-Origin", "*") // 设置允许访问所有域
			context.Header("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE,UPDATE")
			context.Header("Access-Control-Allow-Headers", "Authorization, Content-Length, X-CSRF-Token, Token,session,X_Requested_With,Accept, Origin, Host, Connection, Accept-Encoding, Accept-Language,DNT, X-CustomHeader, Keep-Alive, User-Agent, X-Requested-With, If-Modified-Since, Cache-Control, Content-Type, Pragma")
			context.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers,Cache-Control,Content-Language,Content-Type,Expires,Last-Modified,Pragma,FooBar")
			context.Header("Access-Control-Max-Age", "172800")
			context.Header("Access-Control-Allow-Credentials", "false")
			context.Set("content-type", "application/json")  设置返回格式是json
		}

		if method == "OPTIONS"{
			context.JSON(http.StatusOK, "Options Request!")
		}
		//处理请求
		context.Next()
	}
}