Go中的move_uploaded_file等效项

Question

I am saving an canvas image in png format, and sending it to my server. The string I am sending is in this format...

data:image/png;base64,iVBORw0K...

I want to save this image to a folder called images on my server. But when I look for examples I can't find any. I basically want to do what move_uploaded_file would do in PHP. Right now I have this...

type test_struct struct {
    Test string `json:"image"`
}

func GetImage(rw http.ResponseWriter, req *http.Request, _ httprouter.Params) {

    var img test_struct
    json.NewDecoder(req.Body).Decode(&img)

Now how would I save img.Test, which is the string format above, to a folder in my server so that when I open that folder I can see the image?

Answer 1

If you already have a string with the file encoded in base64, you must to decode it and get the []byte data, and finally write a file with it.

position := strings.Index(img.Test, ",")
if position == -1 {
    // image format doesn't match with 'data:image/png;base64,iVBO...'
}
// decode the base64 string, removing 'data:image/png;base64,' from it
reader := base64.NewDecoder(base64.StdEncoding, bytes.NewBufferString(img.Image[position+1:]))

data, err := ioutil.ReadAll(reader)
if err != nil {
    // error handler
}
// you write the file in wherever you want
ioutil.WriteFile("./image.png", data, 0644)