fixed(api/v1/example/exa_excel.go): 下载模版失败 (#916)

Co-authored-by: Nyangping <yangping@66nao.com>

server/api/v1/example/exa_excel.go

 package example
 
 import (
+	"os"
+
 	"github.com/flipped-aurora/gin-vue-admin/server/global"
 	"github.com/flipped-aurora/gin-vue-admin/server/model/common/response"
 	"github.com/flipped-aurora/gin-vue-admin/server/model/example"
-	"github.com/flipped-aurora/gin-vue-admin/server/utils"
 	"github.com/gin-gonic/gin"
 	"go.uber.org/zap"
 )
@@ -89,12 +90,18 @@ func (e *ExcelApi) LoadExcel(c *gin.Context) {
 func (e *ExcelApi) DownloadTemplate(c *gin.Context) {
 	fileName := c.Query("fileName")
 	filePath := global.GVA_CONFIG.Excel.Dir + fileName
-	ok, err := utils.PathExists(filePath)
-	if !ok || err != nil {
+
+	fi, err := os.Stat(filePath)
+	if err != nil {
 		global.GVA_LOG.Error("文件不存在!", zap.Error(err))
 		response.FailWithMessage("文件不存在", c)
 		return
 	}
+	if fi.IsDir() {
+		global.GVA_LOG.Error("不支持下载文件夹!", zap.Error(err))
+		response.FailWithMessage("不支持下载文件夹", c)
+		return
+	}
 	c.Writer.Header().Add("success", "true")
 	c.File(filePath)
 }