http请求后如何获得响应

Question

I'm studying Go and am a real newbie in this field.

I am facing a problem when I try to copy some value.

What I am doing is:

1. I want to get some response in [response] using httpRequest.

httpClient := &http.Client{}
response, err := httpClient.Do(req)
if err != nil {
   panic(err)
}

1. After that, I want to save the stored value in response at 'origin.txt'

origin_ ,_:= ioutil.ReadAll(response.Body)
f_, err := os.Create("origin.txt")
f_.Write(origin_);

1. And I want to get a specific value by using goquery package.

doc, err := goquery.NewDocumentFromReader(response.Body)
if err != nil {
    log.Fatal(err)
}
doc.Find(".className").Each(func(i int, s *goquery.Selection) {
    w.WriteString("============" + strconv.Itoa(i) + "============")
    s.Find("tr").Each(func(i int, s_ *goquery.Selection) {
    fmt.Println(s_.Text())
    w.WriteString(s_.Text())    
    })
}

)

But in this case, I can get a value exactly what I want from 2) but cannot get anything from 3).

At first, I think the problem is, the response object at 3) is affected by 2) action. Because it is a reference object.

So I tried to copy it to another object and then do it again.

origin := *response

but, I got the same result as first.

What should I do? How can I assign a reference value to another one by its value?

Should I request it twice for each attempt?

Answer 1

I actually don't see where you use shared resources between 2 and 3.

However that being said origin := *response won't buy you much. The data (response.Body) is a io.ReadCloser. The ioutil.ReadAll() will consume and store all the data that the stream has. You only get to do this once.

However you have the data stored in origin. If you need another io.Reader for that data (say for case 3), then you can make that byte slice look like an io.Reader again: bytes.NewReader(origin).