golang语言实现的文件上传与文件下载功能示例

package common
import (
 "io/ioutil"
 "os"
 "path"
 "github.com/gin-gonic/gin"
 "googo.co/goo"
 "googo.co/utils"
)
const (
 UPLOAD_DIR = "static/"
)
type Upload struct {
}
func (this Upload) DoHandle(c *gin.Context) *goo.Result {
 fh, err := c.FormFile("file")
 if err != nil {
  return goo.Err(700, "上传失败："+err.Error(), err.Error())
 }
 f, err := fh.Open()
 if err != nil {
  return goo.Err(701, "上传失败："+err.Error(), err.Error())
 }
 defer f.Close()
 bytes, err := ioutil.ReadAll(f)
 if err != nil {
  return goo.Err(702, "上传失败："+err.Error(), err.Error())
 }
 md5File := utils.MD5(bytes)
 fpath := md5File[0:2] + "/" + md5File[2:4] + "/"
 if err := os.MkdirAll(UPLOAD_DIR+fpath, 0755); err != nil {
  return goo.Err(703, "上传失败："+err.Error(), err.Error())
 }
 fname := fpath + md5File[8:24] + path.Ext(fh.Filename)
 fw, err := os.Create(UPLOAD_DIR + fname)
 if err != nil {
  return goo.Err(704, "上传失败："+err.Error(), err.Error())
 }
 defer fw.Close()
 if _, err := fw.Write(bytes); err != nil {
  return goo.Err(705, "上传失败："+err.Error(), err.Error())
 }
 return goo.Succ(gin.H{
  "url": "/file/" + fname,
 })
}

// 上传文件
r.POST("/upload", goo.Handler(common.Upload{}))
// 下载文件
r.StaticFS("/file", http.Dir("./static"))
// 访问
http://localhost:18000/file/ab/cd/efghijk.png