golang 下载和上传

package main

import (
    "net/http"
    "os"
    "io"
    "strconv"
)


func main() {
    f, err := os.OpenFile("K:/file.exe", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
    stat, err := f.Stat()    //获取文件状态
    if err != nil { panic(err) }  
    url := "http://dl.google.com/chrome/install/696.57/chrome_installer.exe"

    req,err := http.NewRequest("GET",url,nil)
    if err !=nil { panic(err)}
    req.Header.Set("Range", "bytes=" + strconv.FormatInt(stat.Size(),10) + "-")
    resp, err := http.DefaultClient.Do(req)
    if err != nil { panic(err) }
    written, err := io.Copy(f, resp.Body)
    if err != nil { panic(err) }
    println("written: ", written)
}

    http.Handle("/assets/", http.StripPrefix("/assets/", http.FileServer(http.Dir("radio"))))