英文:
Easiest way to download a file?
问题
我可以做类似下面的事情，这会给我一个响应类，但我不确定如何将io.reader写入文件。最直接的方法是什么？
http.Get("https://www.domain.com/some.jpg")
英文:
I can do something like below, which gives me a response class, but I'm not exactly sure how to write the io.reader to a file. What is the most straightforward way?
http.Get("https://www.domain.com/some.jpg")
答案1
得分: 9
如果文件足够小，最简单的解决方案是使用ioutil.WriteFile和ioutil.ReadAll的组合：
resp, err := http.Get("your url")
bytes, err := ioutil.ReadAll(resp.Body)
err = ioutil.WriteFile(filename, bytes, 0666)
如果文件不太小，最好避免创建和填充bytes数组。然后你应该使用io.Copy，它只是将字节从读取器复制到写入器：
resp, err := http.Get("your url")
f, err := os.Create(filename)
defer f.Close()
_, err := io.Copy(f, resp.Body)
在这两种情况下，你必须添加相关的错误处理。
英文:
If the file is small enough the easiest solution is to use ioutil.WriteFile combined with ioutil.ReadAll :
resp, err := http.Get("your url")
bytes, err := ioutil.ReadAll(resp.Body)
err = ioutil.WriteFile(filename, bytes, 0666)
If your file isn't so small, you'd better avoid creating and filling the bytes array. Then you should use io.Copy which simply copies the bytes from the reader to the writer :
resp, err := http.Get("your url")
f, err := os.Create(filename)
defer f.Close()
_, err := io.Copy(f, resp.Body)
You must add the relevant error handling in both cases.
答案2
得分: 0
ReadFrom在某些情况下非常有用：
package main
import (
"net/http"
"os"
)
func main() {
r, e := http.Get("http://speedtest.lax.hivelocity.net")
if e != nil {
panic(e)
}
defer r.Body.Close()
f, e := os.Create("index.html")
if e != nil {
panic(e)
}
defer f.Close()
f.ReadFrom(r.Body)
}
https://golang.org/pkg/os#File.ReadFrom
英文:
ReadFrom is useful in some cases:
package main
import (
"net/http"
"os"
)
func main() {
r, e := http.Get("http://speedtest.lax.hivelocity.net")
if e != nil {
panic(e)
}
defer r.Body.Close()
f, e := os.Create("index.html")
if e != nil {
panic(e)
}
defer f.Close()
f.ReadFrom(r.Body)
}
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