创建接口：

func main() {
    r := gin.Default()
    r.POST("/upload",upload)
    r.Run()
}

// upload 上传
func upload(c *gin.Context)  {
    file, err := c.FormFile("file")
    if err != nil {
        fmt.Printf("111111111upload error:%v \n",err)
        return
    }
    ext := strings.Split(file.Filename, ".")
    if !Container(ext[1],[...]string{"jpg","png"}){
        c.JSON(http.StatusOK,gin.H{"code":1,"msg":"文件格式不支持！"})
        return
    }
    filePath := fmt.Sprintf("./img/%s/",time.Now().Format("2006/01/02"))
    _, err = os.Stat(filePath)
    if err != nil {
        if !os.IsExist(err) { // 目录不存在，创建目录
            err := os.MkdirAll(filePath, os.ModePerm)
            if err != nil {
                fmt.Println(err)
                return
            }
        }
    }
    //文件重命名
    file_name := strconv.FormatInt(time.Now().Unix(),10) + strconv.Itoa(rand.Intn(999999-100000)+100000) + path.Ext(file.Filename)
    filePath = filePath + file.Filename;
   // filePath = filePath + file.Filename;
    err = c.SaveUploadedFile(file, filePath)
    if err != nil {
        fmt.Printf("upload error:%v \n",err)
        return
    }
    c.JSON(http.StatusOK,gin.H{"msg":"ok","path":filePath})
}

// container 判断 target 中是否包含 obj
func container(obj interface{},target interface{}) bool {
    targetValue  := reflect.ValueOf(target)
    switch reflect.TypeOf(target).Kind() {
    case reflect.Array,reflect.Slice:
        for i := 0; i < targetValue.Len(); i++ {
            if targetValue.Index(i).Interface() == obj {
                return true
            }
        }
    case reflect.Map:
        if targetValue.MapIndex(reflect.ValueOf(obj)).IsValid() {
            return true
        }
    }
    return false
}